The Stress Resilience Stack - Temp & Environment

Optimizing your surroundings

One of the most consistent patterns we see at A3 across hundreds of clients and thousands of data points is chronic stress. Not the acute, productive kind, but the low-grade, always-on kind that shows up in suppressed HRV, cortisol that never quite normalizes, and performance that degrades over time. We think of it as the unsung tax on high achievement. This series is a deep dive into a full stack of evidence-based interventions for doing something about it. As we said in Part 1, the research is clear: while there may not be a single magic bullet, multiple moderate interventions quickly add up.

Part 1 covered the entry point: breathing and mental practices. Part 2 tackled the foundations: exercise and sleep. Those are the things you do, the active interventions that require your time and attention.

This post is about something easier to overlook: your surroundings.

We spend enormous energy optimizing our habits and behaviors, but comparatively little attention on the environments that shape them. Yet some of the most reliable interventions we've seen aren't about willpower or discipline at all. They're about design.

Take nutrition, another big focus with our clients. Keeping healthy snacks visible and accessible, adding friction to the crappy stuff, designing your kitchen so the easy choice is the good choice. These changes don't require daily discipline. They work because they change the default.

The same principle applies to stress. Like fish who don't notice water, we tend to be blind to the environments we're immersed in, even as those environments continuously shape our physiology and behavior.

This post covers three layers of environment that affect stress resilience:

• Temperature: deliberate hot and cold exposure as training stimuli;

• Physical surroundings: air quality, light, noise, and the spaces you inhabit; and,

• Social environment: the people around you, and why they might be the most important environmental factor of all.

Let's get into it.

Temperature

In Part 2, we touched on bedroom temperature as a lever for deep sleep. But temperature manipulation goes far beyond keeping your room cool at night. Deliberate exposure to thermal stress—both cold and heat—is one of the most powerful (and underutilized) tools in the stress resilience stack.

The mechanism is, again, hormesis: controlled, recoverable stress that builds adaptive capacity. Cold and heat work through different pathways, but both train your body's stress response systems in ways that carry over to other domains.

Cold Exposure: Dramatic Effects, Accessible Entry Points

The research on cold exposure is striking. A landmark study by Šrámek found that one hour of immersion at 14°C (57°F) produced a 530% increase in norepinephrine and a 250% increase in dopamine above baseline. These aren't small effects; they far exceed what any supplement can produce. And unlike pharmacological interventions that cause brief spikes followed by crashes, cold-induced elevations are prolonged and sustained.

That said, you don't need hour-long ice baths to benefit. Susanna Søberg's research identified the minimum effective dose: approximately 11 minutes total per week, spread across 2-4 sessions of 1-5 minutes each, at temperatures between 50-59°F (10-15°C). That's achievable with cold showers, an outdoor cold plunge, or even a chest freezer conversion if you're committed.

A few practical notes:

End on cold. If you're alternating between hot and cold (sauna then plunge, or hot and cold shower, for example), finishing with cold rather than warming up afterward appears to maximize brown fat activation and metabolic benefits.

The stress response habituates, but the benefits remain. Over 4+ weeks of regular cold exposure, your cortisol and ACTH response to the cold diminishes. You stop experiencing it as stressful. But the benefits (boosted norepinephrine and dopamine) persist. You're training your system to produce the upside without the downside.

Timing matters for strength training. Cold water immersion immediately after resistance training can blunt muscle growth (or hypertrophy), by interfering with the protein synthesis signals that drive adaptation. If you're doing both, do cold exposure on separate days, or either before or 6-8+ hours after lifting.

Cold showers are a legitimate entry point. A large Dutch RCT (n=3,018) found that just 30-90 seconds of cold showering reduced self-reported sick days by 29%. Interestingly, there was no dose-dependent difference between 30, 60, and 90 seconds—minimal exposure was enough to move the needle. If you're not ready for full immersion, a cold shower finish is a great place to start.

Sauna: The Long Game

If cold exposure is about acute activation, sauna is about long-term resilience. The research here is anchored by the Kuopio Ischemic Heart Disease Risk Factor Study—a 20+ year follow-up of 2,315 Finnish men that remains one of the most impressive datasets in lifestyle medicine.

The findings: compared to once-weekly sauna use, 4-7 sessions per week was associated with a 63% reduction in sudden cardiac death, 50% reduction in fatal coronary heart disease, and 40% reduction in all-cause mortality. Sessions exceeding 19 minutes at 80-100°C (176-212°F) showed the greatest benefit.

These are massive effect sizes—larger than most pharmaceutical interventions for cardiovascular risk. And while the study was observational (you can't easily randomize people to decades of sauna use, especially in a country where it's stranger if you don't sauna), the dose-response relationship and biological plausibility make a strong case that the sauna itself is driving outcomes, not just healthy-user bias.

Beyond cardiovascular effects, sauna produces acute hormonal shifts. Growth hormone increases 2-5x with standard protocols, and up to 16x with more aggressive approaches (four 30-minute sessions in a single day with cooling periods between). These effects diminish with habituation, but the cardiovascular and longevity benefits appear to persist with consistent use.

One practical application: sauna 1-2 hours before bed can enhance sleep by raising your core temperature, which then facilitates a steeper drop as you cool down—the same mechanism as the warm bath we mentioned in Part 2. If you have access to a sauna and struggle with sleep onset, evening sessions are worth the experiment.

Access is the main barrier. Unlike cold exposure (where a cold shower is always available), sauna requires either a gym membership with decent facilities, a spa, or a significant home investment. If you have access, the evidence suggests using it frequently (3-4+ times per week) is where the benefits really accumulate. If you don't, this isn't something to stress about. The other interventions in this series will still move the needle.

Physical Surroundings

Temperature is the most dramatic environmental lever, but it's not the only one. The spaces you inhabit, whether your office or home, continuously shape your physiology in ways that are easy to ignore precisely because they're constant.

Air Quality: The Invisible Drag

Most people never think about the air they're breathing indoors. That's a mistake.

Carbon dioxide levels are the clearest example. Outdoor air sits around 400 ppm CO2. But indoor spaces, especially poorly ventilated ones, accumulate CO2 quickly from human respiration. Studies show that at 1,000 ppm, cognitive performance begins to decline across multiple domains (decision-making, strategic thinking, information processing). At 2,500 ppm, strategic thinking becomes what researchers describe as "dysfunctional."

Conference rooms regularly exceed 2,000 ppm within an hour of a meeting starting. Home offices with closed doors aren't much better. You're not imagining that you feel foggy after a long meeting in a stuffy room; you're experiencing measurable cognitive impairment.

The fix is straightforward: ventilation. Open windows when possible. Take breaks that get you into fresh air. If you work from home, don't keep your office door closed all day.

A CO2 monitor ($100-200) is one of the highest-ROI purchases in this entire series. It makes the invisible visible. Once you see your levels climbing past 1,000 ppm, you'll actually open the window. The data changes behavior in a way that abstract knowledge doesn't.

Light: Beyond the Morning

In Part 2, we covered morning light as a circadian anchor. But light environment matters *throughout* the day.

Bright light during daytime hours—especially in the morning and midday—reinforces circadian rhythms and supports alertness. Dim light in the evening, particularly in the 2-3 hours before bed, allows melatonin to rise naturally. The problem is that modern life inverts this: we spend days in dim offices and evenings bathed by screens.

The practical fixes are intuitive: maximize natural light during work hours (sit near windows, take outdoor breaks), and dim your environment in the evening (prioritizing floor lamps rather than overhead lights). Night mode on devices helps marginally, but the bigger lever is overall light levels in your space.

Blue light blocking glasses have become popular, but the evidence is mixed. Studies in healthy adults show minimal objective improvement in sleep outcomes. Put simply, they're not harmful, but they're also not a substitute for actually turning off screens and turning down the lights.

Creating a Serene Space

This one will sound soft compared to cold plunges and CO2 monitors, but the research supports it: your visual and auditory environment affects your stress physiology.

Chronic noise exposure is associated with elevated cortisol and increased cardiovascular risk. Cluttered, chaotic environments are linked to higher baseline stress and impaired focus. Conversely, exposure to natural elements, like plants, natural materials, and views of greenery, produces measurable reductions in stress markers.

The practical application isn't about achieving touch-grass perfection. It's about reducing unnecessary friction in the spaces where you spend the most time:

Noise: If you work in a loud environment, noise-canceling headphones are a legitimate stress intervention, not just a productivity tool. If you control your space, consider background white or brown noise to mask irregular sounds.

Visual clutter: You don't need to Marie Kondo your entire life. But your immediate workspace (the desk, the room you're in most of the day) is worth keeping reasonably clear. The cognitive load of visual chaos is real.

Natural elements: A few plants, natural light, a view of something green if possible. These aren't luxuries. They're low-cost environmental modifications with documented effects on stress and focus.

This might feel like a lower priority than the other interventions in this series. But environment is cumulative. A chronically noisy, cluttered, artificially-lit space is a constant low-grade stressor. Exactly the kind of always-on load we're trying to reduce.

Aromatherapy: Surprisingly Legit

We'll be honest: aromatherapy sounds like it's one step away from crystals and intention candles. But the research is harder to ignore than expected.

A meta-analysis of 65 randomized controlled trials found that lavender inhalation reduces anxiety with an effect size of g = -0.73. That's a large effect, comparable to some pharmaceutical interventions. Oral lavender oil (Silexan, a standardized pharmaceutical-grade extract) has been shown in clinical trials to be comparable to lorazepam 0.5mg for anxiety, without the sedation or dependency risk.

You don't need the pharmaceutical version to benefit. A simple diffuser with lavender essential oil costs $30-50 and, based on the research, produces real acute effects on stress and anxiety. The inhalation route works within minutes.

Especially for acute stress moments or winding down before sleep, it's worth considering. Turns out, sometimes the soft interventions have hard data behind them.

Social Environment

We've covered temperature, air quality, light, and the spaces you inhabit. But there's one more layer of environment that matters more than any of those. And it's the one most likely to get deprioritized when life gets busy: the people around you.

Social Connection: The Irreplaceable Intervention

Here's a statistic that should stop you cold: social isolation carries a mortality risk comparable to smoking 15 cigarettes a day. It's a larger risk factor than obesity, physical inactivity, or air pollution. And yet we treat social connection as a luxury, something to fit in after work is done, if there's time.

The physiological effects are direct and measurable. Partner support during acute stress significantly reduces cortisol response. Close social bonds are associated with higher HRV, lower inflammation, and better immune function. Loneliness, conversely, is associated with elevated cortisol, increased sympathetic activation, and impaired sleep.

This isn't about being extroverted or having a large social network. The research consistently shows that quality matters far more than quantity. A few close, supportive relationships are more protective than a broad but shallow social circle. What matters is feeling genuinely connected, having people who know you, who you can be honest with, and who show up when things are hard.

Why High Achievers Get This Wrong

For the high-achieving, high-responsibility people we work with at A3, social connection is often the first thing to go when demands increase. Work expands to fill available time. Family obligations take whatever's left. And friendships—the relationships that require active maintenance but don't have built-in forcing functions—quietly atrophy.

The logic feels sound in the moment: "I'll reconnect once this project is done, once things settle down, once I have more bandwidth." But things never settle down. And the costs of social disconnection compound silently, in exactly the same way as chronic stress.

Here's the reframe: social connection isn't a reward for finishing your work. It's not leisure. It's a stress intervention, one of the most powerful ones available.

Practical Implications

This isn't a section where we can give you a protocol. There's no "11 minutes per week" minimum effective dose for friendship, regular NY Times articles to the contrary. But there are some principles worth considering:

Prioritize consistency over intensity. Brief, regular contact with close friends is more protective than occasional epic gatherings. A weekly call, a recurring dinner, a standing weekend walk. These rhythms compound over time in ways that sporadic reunion trips don't.

Protect the time proactively. If social connection matters (and the research says it should), it needs to go on the calendar with the same priority as workouts or work meetings. Not "if there's time," but scheduled and defended.

Audit your social environment. Not all relationships are restorative. Some are obligations; some are actively draining. You don't need to cut people out dramatically, but it's worth being honest about which relationships leave you feeling better versus worse, and allocating your limited time accordingly.

Consider the people you live and work with. These are your highest-dose social exposures. A supportive partner, a collaborative team, a household that feels calm rather than chaotic. These aren't just "nice to have." They're the environmental factors that shape your stress physiology daily.

The One Thing You Can't Hack

Throughout this series, we've covered interventions you can stack, optimize, and systematize. Breathing protocols, training programs, temperature exposure, supplements. Many of them can be done solo. That's part of their appeal for self-reliant high achievers.

Social connection is different. It can't be optimized in isolation. It requires vulnerability, reciprocity, and time—things that don't fit neatly into a productivity framework.

Nonetheless, of all the interventions in this series, it might be the one that matters most. Not because the effect sizes are largest in any single study, but because the absence of connection corrodes everything else. Sleep suffers. Resilience drops. The other tools in your stack become less effective when you're running on empty socially.

The people around you are part of your environment. Choose them with care. Invest in them consistently. And don't let the urgent crowd out the essential.

Things to Try Today

We've covered a lot of ground, from ice baths to lavender diffusers to the people you spend time with. Here's how to actually start:

If you're new to cold exposure: Start with cold showers. Finish your normal shower with 30-60 seconds of the coldest water you can tolerate. That's enough to begin building the habit and (based on the Dutch RCT) enough to produce measurable benefits. Work up from there if you want more.

If you have sauna access: Use it more frequently. The benefits accumulate at 3-4+ sessions per week, and evening sessions 1-2 hours before bed can double as a sleep intervention. If you don't have access, don't stress; this one's a bonus, not a requirement.

For an immediate air quality win: Open a window. Seriously. If you work from home or have any control over your space, better ventilation is the lowest-friction fix for cognitive fog. If you want to get precise about it, a CO2 monitor ($100-200) is one of the highest-ROI purchases in this entire stack.

To fix your light environment: Maximize natural light during the day (sit near windows, take outdoor breaks), and dim your space in the evening (prioritizing floor lamps instead of overhead lights). Screens off or dimmed in the 1-2 hours before bed. Night mode helps marginally; actually reducing light levels helps more.

If you're skeptical about aromatherapy: Try it anyway. A lavender diffuser costs $30-50, the effect sizes in the research are legitimately large, and the downside is... your room smells nice. Run it while winding down before sleep and see what you notice.

For your social environment: When did you last have unhurried time with a close friend? Not a work event, not a family obligation, but actual connection with someone who knows you. If you can't remember, that's data. Put something on the calendar this week, even if it's just a 30-minute call. Protect it like you would a workout.

The non-negotiable minimum: Be intentional about at least one environmental factor. Temperature, air quality, light, space, or people. Pick the one where you're currently most exposed to chronic low-grade stress, and make one change. Environment is cumulative; small fixes compound.

What's Next

Environment is the invisible hand shaping your stress physiology. Most people ignore it entirely, which means most people are leaving easy gains on the table.

But there's still one major category we haven't addressed: what you put in your body.

Next up: Nutrition, Supplements, and Adaptogens—from the basics (blood sugar, caffeine) to the things worth considering (ashwagandha, magnesium, creatine, etc.) to the melatonin dosing most people get wrong.

The interventions in this post work for most people—but "most people" isn't the same as you specifically. At A3, we combine biomarker data, genetic insights, and ongoing coaching to help clients figure out exactly which protocols will move the needle for their particular physiology and goals. If you want help building a personalized stack rather than experimenting on your own, we're here to help.

The Stress Resilience Stack: Exercise and Sleep

The non-negotiable foundations

One of the most consistent patterns we see at A3 across hundreds of clients and thousands of data points is chronic stress. Not the acute, productive kind, but the low-grade, always-on kind that shows up in suppressed HRV, cortisol that never quite normalizes, and performance that degrades over time. We think of it as the unsung tax on high achievement. This series is a deep dive into a full stack of evidence-based interventions for doing something about it. As we said in Part 1, the research is clear: while there may not be a single magic bullet, multiple moderate interventions quickly add up.

Part 1 covered the entry point: breathing and mental practices. Those are free, portable, and surprisingly powerful. They're techniques you can use anywhere, anytime, with nothing but your own body and attention.

But here's the thing: those techniques work best when they're built on a solid foundation. You can do all the cyclic sighing and slow breathing you want, but if you're sleeping five hours a night or haven't broken a sweat in months, you're fighting an uphill battle. The breathing practices shift your nervous system in the moment; exercise and sleep determine what your nervous system's baseline looks like in the first place.

That's what this post is about: the non-negotiables. The load-bearing walls of stress resilience that everything else builds on.

Exercise and sleep aren't separate interventions. They're deeply interconnected. Exercise quality affects sleep architecture; sleep quality affects recovery, HRV, and your capacity to adapt to training stress. Get these right, and the other tools in your stack work better. Get them wrong, and you'll undercut the effects of nearly everything else.

The good news: the research here is robust, the protocols are well-established, and the interventions don't require exotic supplements or expensive devices. The bad news: there are no shortcuts. This is where consistency matters more than optimization.

Let's get into it.

Exercise

There's a paradox at the heart of exercise and stress: physical exertion is itself a stressor. It spikes cortisol, elevates heart rate, and temporarily suppresses immune function. Yet regular exercisers consistently show lower baseline cortisol, higher HRV, and better stress resilience than sedentary people.

The resolution is hormesis, the process by which controlled, recoverable stress makes you more resilient to stress in general. Exercise is a training stimulus for your entire stress-response system, not just your muscles. But the details matter. Different types of exercise produce different adaptations, and more isn't always better.

Zone 2 Cardio: Building Parasympathetic Reserve

If there's one type of exercise that earns the "non-negotiable" label for stress resilience, it's Zone 2 cardio—longer-duration aerobic work at 60-70% of your max heart rate (essentially, the pace at which you could still mostly carry on a conversation). Think jogging, cycling, swimming, or brisk walking—anything that keeps your heart rate elevated for 30-60 minutes straight.

The research here is robust. Meta-analyses show that consistent aerobic training produces significant increases in HRV metrics (RMSSD, high-frequency power, SDNN) over 8-12 weeks. Higher training frequencies and longer durations generally produce larger effects, at least when balanced against recovery needs. The sweet spot for most people: 30-60 minutes, 3-5 sessions per week.

Physiologically, Zone 2 training builds your parasympathetic reserve. Regular aerobic exercise increases vagal tone, the strength of your parasympathetic nervous system's influence on your heart. That means a lower resting heart rate, faster recovery from acute stressors, and a higher HRV baseline. You're expanding the capacity of your "rest and digest" system.

Even better, the effects aren't just cardiovascular. Aerobic exercise increases BDNF (brain-derived neurotrophic factor), which supports neuroplasticity and has antidepressant effects. It improves insulin sensitivity, reduces systemic inflammation, and enhances sleep quality. It builds the broadest base of adaptive benefits with the lowest recovery cost.

Before you hop in, one practical note: Zone 2 should feel easy. If you're gasping or can't hold a conversation, you've drifted into Zone 3 or higher. Especially if you're not a already a competitive endurance athlete, you probably need to start much slower than you'd think.

HIIT: Stress Inoculation

High-intensity interval training—short bursts of all-out effort followed by recovery periods—works through a different mechanism than Zone 2. Where Zone 2 builds your aerobic base gradually, HIIT is all about acute stress inoculation.

A typical HIIT session spikes cortisol by roughly 80% immediately post-exercise. Testosterone surges, too. But by 2-3 hours later, both hormones then drop well below baseline (with impressive effect sizes around d = -0.95 to -1.08 for cortisol in particular). Stress followed by super-compensation, also known as "hormesis," is what builds resilience over time.

Research shows that trained athletes display significantly lower cortisol responses to psychological stress compared to untrained individuals. Their systems have learned, through repeated exposure to controlled physical stress, to mount an appropriate response and then recover efficiently. HIIT trains this capacity directly.

That said, there's a ceiling. More than 2-3 HIIT sessions per week, without adequate recovery, will likely tip you into overtraining territory (further discussed below). The stress stops being hormetic, and starts becoming cumulative. If you're already dealing with high life stress (like most of our clients), piling on too much high-intensity training can easily backfire, adding to your total stress load rather than building resilience against it.

The practical recommendation: 2-3 HIIT sessions per week maximum, with at least one full rest day between sessions. If you're new to exercise or in a particularly stressful life period, start with Zone 2 only and add HIIT once your aerobic base is established or life has evened out.

Strength Training: Powerful, but Not Sufficient

Given that strength training is central to what we do at A3, we're adding this section to address the elephant in the room: while resistance training has real benefits for stress resilience, it's probably not enough on its own.

Research shows that strength training can reduce anxiety symptoms, with meta-analyses finding small-to-moderate effect sizes. It improves sleep quality, boosts self-efficacy, and produces favorable changes in cortisol patterns over time. Acute sessions spike cortisol similarly to HIIT, with the same hormetic recovery pattern. And the downstream benefits, like improved body composition, better insulin sensitivity, and increased functional capacity all contribute indirectly to stress resilience.

But there's still a real gap. Strength training doesn't build aerobic capacity or parasympathetic reserve the way Zone 2 cardio does. The HRV improvements from resistance training alone are modest compared to those from sustained aerobic or HIIT work. If you're only lifting and never doing cardio, you're leaving significant adaptations on the table.

Our take: strength training is essential for long-term health, performance, and longevity, and it's a core part of what we program for clients. But for stress resilience specifically, it works best as a complement to aerobic training, not a replacement for it. The ideal stack includes all of the above: Zone 2 for building parasympathetic reserve, strength training for the structural and metabolic benefits, and HIIT used sparingly for high-intensity stress inoculation.

Yoga: Meaningful Effects, Different Pathway

Yoga often gets dismissed as "not real exercise" by the intensity-focused crowd, which is a mistake. Meta-analyses show yoga produces large effect sizes for anxiety reduction. HRV improvements are documented across yoga styles, with increases in high-frequency power and decreases in the LF/HF ratio that indicate a shift toward parasympathetic dominance.

What makes yoga interesting is that it combines physical movement with breath regulation and attentional focus—essentially integrating the breathing practices from Part 1 with low-intensity exercise. For people who find pure cardio tedious or have physical limitations that preclude running or cycling, yoga offers a genuine alternative pathway to stress resilience.

The minimum effective dose appears to be once-weekly, 1-hour sessions, sustained for at least 8 weeks. Two to three sessions per week produces stronger effects. But it’s not a quick fix; like most stress interventions, the benefits compound with consistency.

Nature Walking: The Multiplier

We covered nature exposure in Part 1 as a mental practice, but it's worth revisiting here because combining exercise with nature amplifies the benefits of both.

Walking in nature reduces cortisol by 53%, compared to 37% for urban walking at the same intensity and duration. HRV shows a 104% increase in RMSSD during nature walks. A 50-minute nature walk decreased anxiety, reduced rumination, and improved working memory compared to an urban walk. Same physical activity, dramatically different physiological and psychological outcomes.

The practical implication: if you're choosing between a treadmill and a park, choose the park. If you're choosing between a gym and a trail, choose the trail. You're not sacrificing training quality, you're adding a multiplier. Even 15 minutes of walking in a green space produces measurable changes in stress markers.

Overtraining: The Warning Signs

More exercise isn’t always better. Overtraining syndrome is real, and it's especially insidious because the early symptoms—fatigue, irritability, poor sleep—look a lot like the very stress you're trying to address.

The clearest objective marker is HRV: a sustained decline over 3-4 weeks, despite adequate sleep and nutrition, is a red flag. Other warning signs include unexplained performance plateaus or declines, elevated resting heart rate, persistent fatigue that doesn't resolve with rest, sleep disturbances, mood deterioration, and increased susceptibility to illness.

Prevention is straightforward: build in deload weeks. Every 4-6 weeks, reduce training volume and intensity by 40-50%. This isn't lost progress, it's when adaptation actually consolidates. Monitor your morning HRV if you have a wearable (and remember that trends matter more than absolute numbers). And if you're going through a high-stress life period, consider temporarily reducing training load rather than pushing through.

The goal is to use exercise as a stress inoculator, not to add another source of unrecovered stress to your life.

Sleep

If exercise is where you start building stress resilience, sleep is where you actually lock it in. Every adaptation we just discussed (HRV improvements, hormetic recovery from training, parasympathetic gains) consolidates during sleep. Skimp on sleep, and you're not just tired, you're actively undercutting the impact of your exercise efforts, and degrading the systems that protect you from stress.

Sleep deprivation reliably increases cortisol, reduces HRV, impairs emotional regulation, and compromises immune function. One night of poor sleep is recoverable. But chronic sleep debt compounds. And the effects look remarkably similar to chronic stress itself, because physiologically, that's exactly what it is.

The challenge here is that most high achievers have become completely accustomed to a baseline of suboptimal sleep. Your brain on five or six hours starts to feel normal. Caffeine masks the subjective experience of tiredness. And because the decline is gradual, you lose the reference point for what "well-rested" even feels like. Still, the ugly truth is: you're not fine, you've just forgotten what fine is.

To get things fixed, here's what actually moves the needle.

Morning Light: Anchoring Your Circadian Rhythm

The single most underrated sleep intervention doesn't happen at night. It happens within the first 30-60 minutes after you wake up: exposure to bright light.

Morning light exposure advances your circadian phase, enhances the cortisol awakening response (which you want—it's what makes you alert in the morning), and sets up your melatonin secretion timing for the following night. Meta-analyses show substantial sleep improvement effect sizes (g = 0.39-0.47) from light exposure alone. That's a meaningful impact from something that's completely free.

The key is intensity. Outdoor sunlight delivers 10,000-100,000 lux on a bright day. Even overcast conditions provide 1,000-10,000 lux. Indoor lighting? It looks bright, because your eyes adapt so effectively, but it's typically just 100-500 lux, an order of magnitude too dim to make a difference.

The protocol is simple: 5-10 minutes of direct sunlight exposure within an hour of waking. Longer if it's overcast. Face toward the sun (though, obviously, not staring at it directly), ideally without sunglasses blocking the light from reaching your eyes. Phase shifts are measurable within 2-3 days of consistent practice.

If you work from home or have a flexible morning routine, this is one of the easiest wins in the entire stack: walk outside with your coffee, or eat breakfast by a window. If you’re headed to an office, try to slot sun time into the logistics of your commute. Either way, make light exposure part of your wake-up ritual, not something you stumble into by accident.

Bedroom Temperature: The Deep Sleep Lever

Your body needs to drop its core temperature by about 1-2°F to initiate and maintain deep sleep. Fight this process (with a warm bedroom, heavy blankets, or poor ventilation) and you'll selectively lose slow-wave sleep, the most restorative phase.

Large-scale studies confirm the optimal bedroom temperature for sleep is 60-67°F (15-19°C). A 10°C increase causes a 20% increase in the odds of insufficient sleep. The relationship is consistent and dose-dependent.

Practical fixes: turn down the thermostat (or, in the winter, open the window) at night, use breathable bedding, and consider a warm bath or shower 1-2 hours before bed. That last one is counterintuitive but well-supported. Warming your body before bed actually accelerates a subsequent core temperature drop, shortening sleep onset latency by approximately 36%. (I.e., you're not warming up to sleep warm, you're warming up to cool down faster.)

Similarly, there are dedicated cooling devices (like the Eight Sleep or ChiliPad) that actively regulate mattress temperature throughout the night. They're admittedly pricey, and the peer-reviewed evidence is limited, but our clients have consistently found them overwhelmingly helpful for deep sleep improvements (and their data backs it up). Worth considering if temperature is a clear issue for you, especially if you've already tried out the zero-cost room environment optimizations.

(And, on a related note: temperature is powerful beyond just overnight; we'll go deeper on interventions like cold exposure and sauna in Part 3.)

Caffeine: The Hidden Saboteur

Caffeine has a half-life of 5-6 hours. That means half the caffeine from your 2pm coffee is still circulating at 8pm. A quarter is still there at 2am.

What makes caffeine insidious is that it disrupts sleep architecture even when you feel like you're sleeping fine. You might fall asleep without trouble and stay asleep through the night, but the depth and quality of that sleep is compromised. Slow-wave sleep decreases. Sleep efficiency drops. HRV suffers. And because you don't feel awake at 3am, you don't connect the cause and effect.

The conservative recommendation is a caffeine curfew 8-10 hours before bed. If you hit the sack at 11pm, that means no caffeine after 1-3pm.

But add to that one more wrinkle: caffeine metabolism is hugely genetically variable. Genes like CYP1A2 determine how quickly you clear caffeine, and roughly half the population are "slow metabolizers" who may need even earlier cutoffs. If you've ever suspected caffeine affects you more than others, you're probably right. (That's one of the many reasons we do full genetic sequencing of all our clients.)

Alcohol: The Recovery Killer

This one hurts, as we love a well-mixed negroni or a good montepulciano. But alcohol is a sedative that fragments sleep architecture, suppresses REM throughout the night, and tanks HRV.

The data here is striking. OURA tracked over 600,000 user-nights and found that alcohol consumption was associated with a 15.6% mean decrease in HRV, 35 fewer minutes of sleep, and 6.8% lower sleep scores. This held even for moderate consumption—a glass or two of wine, not binge drinking.

Objectively, there's no "safe" dose of alcohol for optimal sleep quality. If you're optimizing for recovery and stress resilience, alcohol is working against you.

That said, we at A3 aren't teetotalers (just like we still sometimes eat less-than-healthful food, because it's delicious); we're all about crafting a balance between enjoyment and long-term health that works for you now and for the decades to come. If you do choose to drink, finishing 3-4+ hours before bed at least allows some metabolism before sleep, somewhat reducing negative impact. And post-drink nights are also a great time to check in on morning-after changes in HRV; that way, you'll have a clearer sense of the costs (and when they're still absolutely worth it).

Supplements: A Preview

Finally, we'll just mention briefly that there are a slew of evidence-based supplements that support sleep (e.g., melatonin [at much lower doses than most people think], magnesium glycinate and threonate, glycine, and others). Some of them have surprisingly strong research behind them. Still, we're saving the full breakdown for Part 4, where we'll cover all the ingestibles—from basic supplements to adaptogens to more exotic interventions—in one place. For now, the behavioral and environmental factors above are where to start. Fix the foundation before adding supplements on top.

Things to Try Today

We've covered a lot. Here's how to actually start:

If you're not doing regular cardio: Start with Zone 2. Thirty minutes at conversational pace, three times a week. Don't jump straight into HIIT—build the aerobic base first. This is the single highest-leverage exercise intervention for stress resilience.

If you're exercising but still feeling chronically stressed: Check your balance. Too much HIIT relative to Zone 2? Not enough recovery between sessions? Consider swapping one high-intensity session for a longer, easier effort, and watch your HRV trends over the following weeks.

If you want to amplify your existing routine: Move it outside. The same workout in a park or on a trail produces measurably better outcomes than the same workout in a gym. If outdoor training isn't practical, even a 15-minute walk in green space on rest days adds a real multiplier.

For immediate sleep improvement tonight: Drop your bedroom temperature to 65°F, or as low as you can tolerate. This is the fastest environmental fix for deep sleep. If you tend to run hot, try the warm shower trick 1-2 hours before bed to accelerate your core temperature drop.

Starting tomorrow morning: Ten minutes of sunlight within 30 minutes of waking. No sunglasses. Make it part of your routine: walk outside with your coffee, eat breakfast by a window, whatever sticks. Phase shifts happen within days.

If you suspect caffeine is affecting your sleep: Run an experiment. Move your cutoff to noon for two weeks, or cut it entirely for ten days if you're feeling ambitious. Track your sleep subjectively or with a wearable, and see what changes. Most people are surprised.

If alcohol is a regular part of your routine: You don't have to quit, but get honest about the tradeoff. Check your HRV the morning after drinking and compare it to your baseline. Once you see the data, you can make informed decisions about when it's worth it, and when it's not.

The non-negotiable minimum: Seven to eight hours of sleep opportunity (time in bed, not just time asleep). Morning light daily. Some form of movement most days—ideally including Zone 2 cardio at least three times a week.

What's Next

Exercise and sleep are the load-bearing walls. Get these right, and everything else in the stack works better. Get them wrong, and you're constantly compensating.

But there's more to the environment than your bedroom temperature.

Next up: Temperature and Environment—cold exposure, sauna, CO2 and air quality, and why the people around you are part of your "environment" too.

[And one closing note: the interventions in this post work for most people—but "most people" isn't the same as you, specifically. At A3, we combine biomarker data, AI analysis, and ongoing coaching to help clients figure out exactly which protocols will move the needle for their particular physiology and goals. If you want help building a personalized stack rather than experimenting on your own, we're here to help.]

The Stress Resilience Stack: Breathing and Mental Practices

Free, immediate tools you can use anywhere

After hundreds of clients and thousands of data points, one of the most consistent patterns we see at A3 is chronic stress. Not the acute, productive kind that sharpens your focus before a big pitch, but the low-grade, always-on kind. The kind that shows up in suppressed heart rate variability, cortisol curves that never quite normalize, and inflammatory markers that slowly creep in the wrong direction.

We think of it as the unsung tax on high achievement. The cost of caring deeply about your work, carrying real responsibility, and operating at a pace that doesn't leave much room for recovery.

Sure, you adapt. The baseline shifts. "Tired" becomes normal. "Wired" becomes your daily operating system. You stop noticing, until you're dealing with consequences that take far longer to reverse than they took to accumulate. Problem is, that same pattern doesn't just create long-term risk; it degrades performance right now: accelerated aging, impaired cognition and decision-making, worse sleep, higher fat, less muscle, slower recovery, and degraded performance right now. The very things high achievers are actually trying to optimize.

You've already heard the obvious advice, which is frankly useless. "Just stress less" isn't a strategy. You're not going to quit your job and sit on a beach, appealing as that may sometimes seem. The stressors are, instead, inseparable from the things that give your life meaning. So what actually works?

The Stack Approach

First, let's be honest: there isn't a single silver bullet here. But there is a surprisingly deep toolkit of interventions, each backed by varying degrees of evidence, each working through different mechanisms. And the research is clear: layering multiple moderate interventions beats chasing a single perfect solution.

That said, not all interventions are created equal. Some have robust clinical trial data and large effect sizes. Others are mostly marketing and social media hype. Some work in minutes; others take months. Some are free; others cost hundreds of dollars a month.

That's what this series is about: cutting through the noise, evaluating what actually works, and helping you build a realistic, personalized approach.

The Stress Resilience Stack

Over five posts, we'll cover:

• Breathing and Mental Practices (this post) — free, portable, immediate tools.

• Exercise and Sleep — the non-negotiable foundations.

• Temperature and Environment — optimizing your surroundings (both physical and human).

• Nutrition, Supplements, and Adaptogens — what to put in your body.

• Pharmaceuticals and Building Your Protocol — prescription solutions, and then an actionable synthesis of all the research.

Each post ends with concrete "try this today" recommendations. The final post will help you assemble your own stack based on your goals, your constraints, and what the evidence actually supports.

This Post: Your Anywhere, Anytime Toolkit

We're starting with breathing and mental practices for a reason: they're surprisingly powerful _and_ inherently portable. No equipment, no supplements, no gym membership required. You can use them in a cab before a board meeting, at your desk between calls, or lying in bed when your mind won't shut off.

Some of the strongest effect sizes in the entire stress literature come from techniques you can learn in five minutes. Let's get into it.

Breathing & Body Practices

Here's something worth appreciating: breathing is the only autonomic function you can consciously control. Your heart rate, digestion, and hormonal responses all run on autopilot—but you can decide, right now, to take a slow breath. That makes breathing a direct lever for shifting your nervous system state, and the research backs this in ways that might surprise you.

Slow Breathing (5-6 breaths per minute): The Gold Standard

If you only take one thing from this post, it's this: slowing your breathing to around six breaths per minute is one of the most well-supported interventions in the entire stress literature. Meta-analyses based on over 200 studies show significant increases in heart rate variability (a key marker of parasympathetic activation) both during practice and afterward, along with meaningful reductions in blood pressure.

The protocol is dead simple. Inhale for about five seconds through your nose, exhale for about five seconds through your nose or mouth. That's roughly six breaths per minute. Even a few minutes helps, though research shows benefits increase with sessions up to ten or twenty minutes. That's it.

At this breathing rate, you're hitting what's called "resonance frequency," the point where your respiratory and cardiovascular rhythms sync up, maximizing the efficiency of your heart rate variability response. Most people's resonance frequency falls somewhere between 4.5 and 6.5 breaths per minute, so the standard "six per minute" guidance is a solid starting point for nearly everyone.

The effects are both immediate (you'll feel calmer within a few minutes) and cumulative (regular practice builds parasympathetic tone over time). Zero cost, zero side effects, can be done anywhere.

Cyclic Sighing: The Stanford Standout

A 2023 Stanford study put cyclic sighing head-to-head against mindfulness meditation. And cyclic sighing won. Participants who practiced cyclic sighing showed significantly greater improvements in positive mood compared to those who meditated, plus significant reductions in anxiety. Even better, it only took five minutes a day.

The technique is simple: take a full inhale through your nose, then—without exhaling—take a second, shorter inhale to completely fill your lungs. Then exhale slowly and fully through your mouth. Repeat for five minutes.

That double inhale is doing something specific: it reinflates the tiny air sacs in your lungs (alveoli) that partially collapse during normal breathing, which optimizes carbon dioxide offloading on the exhale. The long exhale activates the parasympathetic nervous system. Put simply, you're hacking your way into a calmer state through mechanical means.

This one, too, has both immediate (you'll notice a shift within the session) and cumulative (benefits increased with consecutive days of practice in the Stanford trial) effects. And it's probably the single best "bang for your buck" breathing technique for most people.

Progressive Muscle Relaxation (PMR)

PMR has been around since the 1930s, and it's accumulated a serious evidence base—over 40 randomized controlled trials showing effectiveness for stress, anxiety, and depression. The approach is simple: you systematically tense and then release different muscle groups, which triggers a reflexive relaxation response.

A typical session takes 15-20 minutes and moves through the body: hands, forearms, upper arms, forehead, eyes, jaw, neck, shoulders, chest, stomach, hips, thighs, calves, feet. For each group, you tense the muscles for about five seconds, then release and notice the contrast for 15-30 seconds.

PMR is valuable in parallel to breathing techniques, as it works through a different pathway. By deliberately creating and then releasing muscle tension, you're training your body to recognize what relaxation actually feels like—something many chronically stressed people have genuinely forgotten. It also tends to work well for people who find pure breathing exercises or meditation too "passive" or who struggle with a racing mind.

The effects are immediate, and like breathing practices, the skill deepens with repetition. Many people find PMR particularly useful before sleep. Free guided sessions are easy to find on YouTube if you want something to follow along with.

NSDR and Yoga Nidra: Structured Deep Rest

Non-Sleep Deep Rest (NSDR)—a term popularized by Andrew Huberman, essentially rebranding the ancient practice of Yoga Nidra—has become a wellness buzzword. But beneath the hype, there's legitimate science.

Yoga Nidra is a guided practice where you lie down, remain still, and follow verbal cues that move your attention through your body while hovering in the state between wakefulness and sleep. Sessions typically run 10-30 minutes. Studies show it can reduce cortisol, improve sleep quality, and decrease anxiety, with some research demonstrating significant improvements in as little as two weeks of regular practice. There's also emerging evidence around dopamine restoration, which is part of why Huberman has promoted it as a recovery tool.

What makes NSDR/Yoga Nidra interesting is that it's more accessible than meditation for many people. You're not trying to "clear your mind" or focus on your breath, you're just following instructions and letting your body drop into a restorative state. Particularly useful for the many type-A people who are convinced they "can't meditate."

The main barrier is time: you'll need 20+ minutes for maximum impact, and you need to be lying down in a quiet place. But for recovery days, travel, or periods of high stress, it's a powerful tool. Free guided sessions are widely available on YouTube and apps like Insight Timer.

Box Breathing: The Tactical Standard

Box breathing—inhale for four seconds, hold for four seconds, exhale for four seconds, hold for four seconds—is the standard in military and first-responder communities. Navy SEALs use it. So do elite athletes and surgeons.

The evidence base is moderate (not as robust as slow breathing), but the effects are real and the technique is dead simple to remember under pressure. The holds add an element of CO2 tolerance training, and the rigid structure gives your mind something to focus on, which can be helpful when anxiety is spiking.

Box breathing is probably best thought of as a tactical tool—something you pull out in acute moments of stress—rather than a daily practice. Before a difficult conversation, during turbulence, when you feel your heart rate climbing before a presentation. It's not going to transform your baseline the way daily slow breathing will, but it's a reliable way to take the edge off in the moment.

HRV Biofeedback: Worth the Investment?

HRV biofeedback involves using a device (chest strap or finger sensor) to see your heart rate variability in real time, then practicing techniques to improve it. Meta-analyses show large effect sizes for stress and anxiety reduction.

But here's the important caveat: when researchers compare HRV biofeedback to simple slow breathing without any feedback, the outcomes are essentially equivalent. The biofeedback isn't adding much beyond what you'd get from just breathing slowly.

So what's it good for? Adherence and engagement. If you're the kind of person who responds to data, gamification, and visible progress, biofeedback might help you actually stick with a breathing practice. The real-time feedback can also help you find your personal resonance frequency more precisely. But if you're willing to just do the breathing without the gadget, you'll get the same physiological benefits.

Our take: nice to have, not need to have. Don't let the lack of a device be an excuse not to practice.

Wim Hof Method: Controlled Stress as Training

The Wim Hof Method—cyclic hyperventilation followed by breath holds, often paired with cold exposure—has genuine science behind it. Trained practitioners show dramatically altered immune responses: in one notable study, Wim Hof practitioners injected with bacterial endotoxin showed 50% lower inflammatory cytokines and 200% higher adrenaline compared to untrained controls. The method appears to give practitioners a degree of voluntary control over their stress response that was previously thought impossible.

The protocol involves 30-40 deep, rapid breaths, followed by a breath hold on the exhale, repeated for several rounds. It's intentionally activating. You're deliberately spiking your sympathetic nervous system, which is the opposite of the calming techniques above. The theory is that controlled, voluntary stress exposure builds resilience and regulatory capacity over time.

One critical safety note: never practice the breathing component in water. The hyperventilation can cause lightheadedness or, in rare cases, loss of consciousness—not dangerous on your couch, but potentially fatal in a pool or bathtub. Several drowning deaths have been linked to this exact mistake. Keep the breathwork on dry land and you're fine.

The cold exposure component (which we'll cover in the Temperature post) can be practiced separately and is arguably the more accessible entry point. But if the idea of training your stress response through deliberate, controlled activation appeals to you, the Wim Hof breathing protocol is worth exploring.

Mental Practices

If the breathing and body techniques above work primarily through bottom-up mechanisms—changing your physiology to shift your mental state—the practices in this section work more top-down. They change how you relate to stress cognitively, which in turn affects your physiological response. Both approaches are valuable, and they complement each other well.

Mindfulness Meditation: The Heavy Hitter

Let's start with the elephant in the room. Mindfulness meditation has the deepest research base of any mental practice for stress reduction. We're talking dozens of meta-analyses of further dozens of randomized controlled trials with thousands of participants in turn. The effect sizes are medium to large for stress reduction, with documented improvements in cortisol levels, heart rate variability, and even structural changes in brain regions associated with emotional regulation.

The gold standard protocol in research is Mindfulness-Based Stress Reduction (MBSR): an eight-week program involving 2.5 hours of weekly instruction plus 45 minutes of daily home practice. That's a significant commitment, and it's worth being honest about that upfront.

The good news: you don't necessarily need the full program to see benefits. Briefer protocols (four weeks, only 10-15 minutes a day of practice) have also shown meaningful effects. App-based approaches like Headspace have been studied in over a dozen RCTs, with effect sizes comparable to in-person instruction for many outcomes.

The challenge with meditation is that it requires genuine consistency to work, and most people don't stick with it. If you've tried meditation before and bounced off, that's useful data. It might mean you need a different approach (guided vs. unguided, app vs. class, shorter sessions; we're big fans of the app The Way), or it might mean one of the other practices in this post is a better fit for you. Put differently, the best stress intervention is the one you'll actually do.

Nature Exposure: The Easiest Win

Here's something that might surprise you: simply being in nature—even briefly—produces measurable physiological changes. A large-scale Japanese research program studying "forest bathing" (shinrin-yoku) across 24 forests and 280 subjects found that just 15 minutes of walking or sitting in a forest environment reduced cortisol by 13-16%, lowered blood pressure, decreased pulse rate, and shifted heart rate variability toward parasympathetic dominance.

The effects aren't limited to remote forests. Urban parks work too. (Central Park, we're looking at you.) One study found that a 50-minute nature walk decreased anxiety, reduced rumination, and improved working memory compared to a city walk of the same duration. Even 15 minutes produces measurable changes.

What makes nature exposure particularly valuable is that it requires zero skill or practice. You don't have to learn anything or maintain focus. You just have to show up and be there. For people who struggle with more structured practices, this is often the path of least resistance—and the research suggests it's genuinely effective, not just "nice."

The one caveat: the benefits are dose-dependent. More time produces stronger effects, with research suggesting two or more hours per week as a threshold for robust benefits. But even brief exposures help, and something is always better than nothing.

Expressive Writing: Processing on Paper

Expressive writing (sometimes called therapeutic journaling) has an evidence base dating back to the 1980s and psychologist James Pennebaker's original studies. The classic protocol is simple: write for 15-20 minutes about your deepest thoughts and feelings regarding a stressful experience, for three to four consecutive days.

Meta-analyses show small but significant effects on psychological distress, anxiety, and depression, with benefits that persist for months after the writing sessions. There's also evidence for reduced cortisol reactivity to subsequent stressors—essentially, processing past stress on paper makes you more resilient to future stress.

The mechanism appears to involve cognitive processing: putting difficult experiences into words helps organize and make sense of them, reducing the ongoing mental load of unprocessed emotion. It's not about venting or complaining. Instead, research suggests that writing which moves toward meaning-making and insight produces better outcomes than pure emotional expression.

That said, this isn't a daily practice for most people. It's more of a tool to pull out when you're dealing with something specific, whether a difficult transition, an unresolved conflict, or a period of high stress. Twenty minutes of honest writing about what's actually bothering you can be surprisingly clarifying.

Cognitive Reappraisal: Reframing on the Fly

Cognitive reappraisal is less a "practice" and more a learnable skill, the ability to reframe how you interpret a situation in order to change your emotional response to it. Meta-analyses consistently identify it as one of the most effective emotion regulation strategies, with research showing it reduces both the subjective experience of negative emotions and physiological markers like cortisol.

The basic move is simple: when you notice yourself reacting strongly to something, pause and ask whether there's another way to interpret the situation. Not toxic positivity ("everything happens for a reason!"), but genuine reframing. The meeting that got canceled might be frustrating, or it might be unexpected time to prepare for tomorrow. The critical feedback might feel like an attack, or it might be useful data from someone who cares enough to be honest.

What makes reappraisal powerful is that it's portable and instantaneous. You don't need to set aside time for it. You can do it in the moment, as stress is happening. The skill develops with practice—the more you do it, the more automatic it becomes.

One nuance: reappraisal works best for situations that are genuinely ambiguous or where your initial interpretation might be distorted. For situations that are objectively bad, trying to reframe can backfire. Sometimes the appropriate response to a terrible situation is to feel bad about it, and then figure out what to do.

Gratitude Practices: Small but Real

Gratitude interventions (typically involving writing down things you're grateful for) show up frequently in the positive psychology literature. The effect sizes are small but statistically significant. Improvements in wellbeing, life satisfaction, and mild reductions in anxiety and depression symptoms.

The most-studied approach is the "Three Good Things" exercise: each day, write down three positive events from the day along with a brief explanation of why they happened. Studies show benefits persisting up to six months after the intervention period.

Interestingly, there's evidence that less frequent practice might work better than daily practice. Once or twice a week may outperform daily gratitude journaling, possibly because daily practice leads to habituation, as the exercise starts to feel rote and loses its impact.

Our honest take: gratitude practices are low-cost and low-risk, and they work for some people. But while they're very frequently discussed, the effect sizes are smaller than the other interventions in this post, and they can feel forced or artificial for certain personalities. If it resonates with you, great. If it feels like empty positivity, don't force it. Your time is probably better spent on slow breathing or nature exposure.

Things to Try Today

We've covered a lot. Here's how to actually start:

If you have five minutes right now: Try cyclic sighing. Double inhale through your nose (fill your lungs, then take a second sip of air to top them off completely), then slow exhale through your mouth. Repeat for five minutes. Notice how you feel afterward. This is the single fastest way to test whether breathing techniques work for you.

If you want one daily practice: Slow breathing at six breaths per minute, ten minutes a day. Inhale for five seconds, exhale for five seconds. Morning or evening, doesn't matter—just pick a time you can protect. The evidence base here is enormous, the barrier to entry is zero, and the cumulative effects build over weeks.

If you want to go deeper: Meditation is the most-researched intervention in this post, with the largest long-term effects. But it requires real commitment. Start with ten minutes a day, guided or unguided, and protect that time for at least four weeks before deciding if it's working. Apps like Headspace or The Way lower the barrier; classes or MBSR programs add structure and accountability. Or you can just run a timer for ten minutes, and watch your breath. Regardless of your path, it's not a quick win, but a slow and compounding one.

If you're skeptical of all this: Run an experiment. Pick one technique (cyclic sighing, box breathing) and use it before your next stressful moment. A difficult conversation, a high-stakes meeting, a flight you're dreading. Just once. See what happens. You don't have to believe it works; you just have to try it and notice.

If you "can't meditate": Get outside. A 15-minute walk in a park is not a consolation prize—it's a genuine, research-backed intervention with effect sizes comparable to formal practices. If sitting still with your thoughts feels impossible, nature exposure might be your path in.

If you're dealing with something specific: Try expressive writing. Twenty minutes, three or four consecutive days, writing honestly about what's bothering you. Not for anyone else to read, just for processing. This works best for discrete stressors rather than general background anxiety.

What you don't need: An app (though they can help). A device (HRV biofeedback isn't superior to plain breathing). Money. A lot of time. The most effective techniques in this post are free and take five to ten minutes.

And most of all, remember: the best practice is the one you'll actually do. Start with one thing, do it for a week, and notice what changes.

What's Next

Breathing and mental practices are the foundation of the stack because they're always available. They cost nothing. They work immediately. And they compound over time.

But they're not the whole picture.

Next up: Exercise and Sleep—the non-negotiable foundations that everything else builds on. In future posts, we'll cover why Zone 2 cardio builds long-term stress resilience, how temperature affects deep sleep more than most people realize, the hidden ways caffeine and alcohol undermine your recovery even when you think you're fine, and more.

And, finally: the tools in this post work for most people—but "most people" isn't the same as you, specifically. That's why we built A3. From biomarker data to genetic insights, we use AI analysis and expert coaching to help clients figure out exactly which interventions will move the needle most for their particular physiology and then integrate them into their lives. If you want assistance in building a personalized protocol rather than experimenting on your own, we're here to help.

The PB6 Diet: A No-Nonsense Approach to Eating for Busy Professionals

Given the level of bullshit in the health and fitness world—especially around diet and nutrition—let's get something straight up front: the PB6 diet isn't magic. It's just a very easy and sustainable approach to eating that has reliably helped many of our clients at A3 Health lose excess body fat and improve their health biomarkers over time.

If you're like our clients, you're smart, motivated, and already have a pretty good sense of what you "should" be eating. But you're also incredibly busy, have a ton of other priorities, travel frequently, and eat a large percentage of your meals out—often in social settings, whether for work or pleasure, where you want to eat like a normal person and enjoy yourself.

The PB6 Diet is designed with that reality in mind. It's extremely simple, doesn't require tracking or weighing or measuring, and lets you eat pretty much anything. Instead, it leverages some easy heuristic rules—built on a large body of behavioral psychology and nutritional biochemistry research—to keep you from going overboard, and to help you make slightly healthier choices over the course of your day.

As our clinical testing has demonstrated, if you stick to these rules day in and day out, you'll end up making real change, fast.

Who This Is For (And Who It's Not)

This approach works best for: busy professionals who eat out frequently, travel for work, have unpredictable schedules, and want something sustainable rather than restrictive. If you're carrying some excess body fat and want to lose it without upending your life, PB6 is built for you.

This probably isn't ideal for: competitive athletes with highly specific performance nutrition needs, people with medical conditions that require specialized diets, or anyone who wants the *most* effective approach possible rather than the most practical one. PB6 is a solid 80/20 solution—if you want the extra 20%, that requires actual testing (bloodwork, genetics, metabolic markers) and individualized programming, which is what we do at A3 but isn't something a general framework can deliver.

The Entire Diet in Four Rules

1. Fast 16 hours overnight. When you stop eating at night—whether food or calorie-containing beverages—start a timer, then don't eat again until 16 hours later. That might mean you stop eating post-dinner at 9pm, then have lunch at 1pm the next day. Or end at 10pm and start again at 2pm, or 8pm and noon. While fasting, you can (and should) still drink water, seltzer, coffee, and tea.

2. From the end of your fast until 6pm, eat Paleo. Eat Paleo-diet-friendly foods for lunch and any afternoon snacks.

• Eat: meat, fish, eggs, vegetables, fruits, nuts, seeds, herbs, spices, healthy fats and oils (like olive oil, coconut oil, or avocado oil).

• Don't eat: grains, legumes, dairy, processed foods, sugar, artificial sweeteners, industrial fats and oils.

3. If you work out on a given day, eat whatever you want from 6pm until the start of the overnight fast. Alcohol is also okay, though ideally don't go past two drinks.

4. If you don't work out, keep eating Paleo until the start of the fast. And skip the drinks.

That's it.

Why This Works

One of the main reasons PB6 works is that, unlike most diet approaches, it's simple and flexible enough to be sustained over the long haul—while still building on several research-backed principles.

Intermittent Fasting

Honestly, intermittent fasting is a bit over-hyped. But it does have enough upsides to make it worth including, especially because most people find it actually makes their lives easier, requiring basically zero work once they get into the rhythm of it. Ongoing research has pointed towards promising potential upsides—from increased cellular autophagy (your body's first line of defense against cancers), to better regulation of cholesterol and multiple hormones. However, we've included it mostly because it helps people naturally eat less over the course of the day, making it a painless way to drop unwanted weight.

Paleo

This one also cuts into fad diet territory, but there's solid research backing up the positive impact of a Paleo approach on everything from glucose tolerance to blood pressure and triglycerides. More importantly, a midday stretch of Paleo naturally moves people towards the handful of changes common across all successful, healthy diets: it increases food quality, prevents nutrient deficiencies (biasing sufficient protein, essential fatty acids, and vitamins and minerals), and constrains energy intake to help drop excess body fat.

Habit Reinforcement and Carb/Calorie Cycling

You already know you'd be healthier if you exercised more. The hard part is actually, reliably doing so. Using a given day's workout as the key to "unlock" free eating that evening builds on a large body of research on habit formation to positively reinforce an exercise habit. At the same time, it creates a rhythm of both carb and calorie cycling, increasing your carbohydrate and overall calorie intake at times when you're most likely to use those nutrients to build new muscle, and reducing them when you're more likely to store them as fat instead.

[Sources]

Common Questions

Won't I get really hungry?

For the first few days, possibly. Hunger is complex, regulated by a variety of physiological, psychological, and environmental cues. However, reliably getting hungry at certain times of day is mostly driven by a pair of hormones (Ghrelin, which increases appetite, and Leptin, which decreases it) tied to your circadian rhythm. If you normally eat breakfast at 8am, those hormones will cue up hunger in preparation, causing your stomach to rumble at 7:30am.

Fortunately, research has shown that both hormones can be quickly retrained to a new schedule. While skipping breakfast might feel rough for two or three days, by the fourth, you likely won't feel hungry in the morning at all. We frequently hear from clients that once they get rolling with PB6, they sometimes forget to eat entirely until mid-afternoon.

What counts as a 'workout'?

Look at your current fitness level and use common sense. If you're at least moderately fit, a "workout" probably entails some kind of focused strength and/or conditioning session, whether in the gym or at home. If you haven't exercised in years, it might just be a 30-minute brisk walk. Either way, it should feel at least sort of hard, and after doing it a bunch of days in a row you should probably feel like you want a day off to recover.

If I work out in the morning, don't I need to eat after?

Maybe. PB6 done "as is" works best if you work out midday (before lunch) or late afternoon (before dinner). If you work out in the morning and don't break your fast until after noon, you have a choice: if you're strictly trying to maximize fat loss, stick with fasting. The "post-workout nutrition window" is indeed a thing, but it's not nearly as brief or impactful as many fitness professionals make it seem. If you're primarily focused on maximizing muscle gain, consider consuming some protein (around 25-35g) shortly after you work out.

Can I really 'eat whatever I want' after 6pm?

Basically, yes—though you'll make faster progress if you're not a total dick about it. The idea here is that if you work out, you have the freedom to eat things that seem delicious after 6pm. However, there's a difference between eating a slice of cheesecake and eating the entire cheesecake. As the old saying goes, the dose makes the poison. So enjoy what's calling to you. But also remember that you can eat whatever you want regularly, so there's no need to go completely overboard on any given night.

Can I put milk or cream in my coffee during the fast?

We think you shouldn't, but mostly because we're coffee snobs who know the correct answer is black. If you want to add a tablespoon or two of milk or cream to your morning coffee, go for it—it's definitely not going to throw off the whole diet.

So I can never eat breakfast again?

No, you absolutely can. We intentionally designed PB6 to be anti-fragile; unlike something like nutritional ketosis, it won't break entirely just because you don't stick to it perfectly. If you mostly follow the rules, you'll get most of the results. Whether you don't want to look rude at a breakfast meeting, don't want to miss out on the great buffet at a hotel on vacation, or just wake up feeling extra ravenous one day, you can still have breakfast occasionally and be totally fine. Just don't do it all the time. (And since breakfast is technically before 6pm, bonus points if you keep it Paleo—say, an omelette plus a side of fruit.)

Wait, isn't this whole thing basically just an elaborate ploy to make me exercise more and eat less?

No shit. But that's kind of the point: the best diet is one you'll actually stick to, and PB6 is designed to make eating less and exercising more feel like the path of least resistance rather than a daily battle of willpower.

What to Expect

By itself, the PB6 diet is surprisingly powerful. If you're carrying excess body fat, we find that most people who follow it strictly lose about a pound a week.

However, there's obviously a ton more you can do to improve your fitness and health, both now and over the long term. Nutrition is just one piece of the puzzle—how you train, how you recover, how you sleep, and dozens of other factors all interact to determine your overall trajectory.

At A3 Health, we take a data-driven approach to all of it: comprehensive biomarker testing, genetic and epigenetic analysis, movement assessments, and AI-powered analysis to build hyper-personalized plans.

But even without all that, PB6 is a solid foundation that works for most people, most of the time.

Give it a shot for a few weeks and see how you feel.

The Injury You're Creating Right Now: Why Intelligent Prehab Beats Reactive Rehab

John trained smart: he read the articles, hired a running coach to design his half-marathon training, and arranged it all to wedge in around his busy schedule as a partner at a real estate fund.

When his hips felt tight, he stretched. When his IT band flared up, he whipped out the Theragun, and foam-rolled.

Six weeks before race day, he felt some nagging discomfort in his knee, but he pushed through his tempo run nonetheless.

The next morning, he could barely walk.

And it got worse over the course of the week.

One MRI later: torn meniscus, surgery recommended, race cancelled, and six months of physical therapy ahead.

But the real cost wasn't the lost race. It was the month of terrible sleep, the brain fog during a critical fundraise, and the realization that he'd been managing his own body in a way that he'd never manage his company.

When John first came to see us at A3, we shared good news and bad news. We told him we were pretty sure we could get him back to 100% without surgery. (Turns out, we were right.) BUT, we also told him that, had he come in 18 months earlier, we could have prevented the tear in the first place. His injury was entirely predictable from just our first set of movement and structural balance testing.

Most people treat injuries as random bad luck. Yet they'd never approach their businesses that way. Instead, they model risks, build redundancy into critical systems, and fix small issues before those spiral out of control.

Turns out, a similar approach works in the gym, too: assess measurable imbalances, use those to predict injury risks, and then backcast to training and other changes that can head off the injuries in the first place.

At A3 Health, a data-driven performance company in New York, I've spent years watching high performers make this exact mistake. They bring analytical rigor to every aspect of their lives except the one thing that makes everything else possible: their body.

Why the Old Model Fails: "Get Stronger, Hope for the Best"

Here's the standard advice you'll find online: lift three times a week, do some cardio (don't forget the Zone 2!), "work on mobility," maybe throw in a YouTube "prehab" routine if you have an especially touchy shoulder or knee.

Which, honestly, isn't bad advice. You'll get stronger, improve your cardio, and feel FAR better than if you just sat on your butt and did nothing.

But it's also fundamentally blind.

That generic training approach increases your capacity without reducing (and in many cases exacerbating) your injury risk. It doesn't account for the specific ways you're likely to break:

• Maybe your strength is asymmetrical. Your left hamstring is 15% weaker than your right, but it feels totally normal to you.

• Maybe your mobility is great in some planes but missing where it actually matters. Your golf backswing is full of wonky cover-ups for reduced t-spine rotation or shoulder internal rotation.

• Maybe you've developed compensatory movement patterns that you can't see yourself—one knee tracks inward when you squat, or your lower back does all the work that your glutes should be in your deadlift.

And that's the real gap in the standard model: you're not searching out the weak links that in turn model how you're likely to break.

Most people only get sophisticated feedback after they're already in pain. That's when you finally see an orthopedist, get an MRI, start physical therapy. And here's the frustrating part: a good PT will then run you through tests for joint angles, strength asymmetries, and faulty movement patterns. They'll identify the exact imbalances that caused your injury.

In other words, they do the same kind analysis you needed 18 months ago when you felt "fine."

That's like doing crash investigations after the accident, instead of safety inspections before the part fails. We're being reactive when we should be predictive.

The exercises your physical therapist prescribes post-injury? Those same exercises—or smarter, more real-world applicable ones—would have prevented the injury if you'd done them before it happened.

Intelligent Prehab & Backcasting: Preemptive Physical Therapy

So what's the alternative?

It starts with reframing what "prehab" actually means. Most people think of prehab as those random activation drills you do before your workout—some band pull-aparts, maybe a few glute bridges, whatever your Instagram algorithm served up that morning.

That's not prehab. That's warm-up theater.

Real intelligent prehab is a structured system to identify your most likely future injuries, then build prevention into the center of your training plan—not tacked onto the margins. Think of it as preemptive physical therapy baked into your program from day one.

The key concept here is backcasting—borrowed from scenario planning and strategic forecasting. Instead of looking forwards, start from potential negative outcomes, and then work backwards to figure out what predicts them, and therefore what might prevent them in the first place.

The process for applying that to injury is conceptually simple:

1. Start with a list of specific potential bad outcomes that you're demographically at risk for (if you're a 50-year-old desk jockey, perhaps that's ACL tear, rotator cuff impingement, lumbar disc herniation, etc.).

2. Ask: "What patterns and imbalances typically precede each of those injuries?"

3. Look for those exact patterns in your data right now.

4. If you find them, you've identified a high-risk failure mode.

5. Build your training around addressing those high-risk patterns and imbalances to close the gap.

Here's what it looks like in a concrete example: research shows that 70-80% of non-contact ACL tears in recreational athletes share a handful of common precursors—reduced hip internal rotation, weak glute medius, poor single-leg stability, knee valgus collapse under impulse or load.

If you show up with those exact markers, we don't need to wait around to see if you tear your ACL. We already know you might Your job is to fix the pattern before the ligament fails.

You already do this in business. You don't wait for your top engineer to quit before you think about succession planning. You don't wait for your server to crash before you set up backups. You imagine the failure mode, work backward to the warning signs, and solve the problem in advance.

Intelligent prehab applies that same logic to your knees, hips, shoulders, and spine.

The difference between someone who trains for 20 years without major injury and someone who's constantly managing an endless list of tweaks and stretches of time off isn't luck. It's whether they're addressing their specific weak links before those weak links break—or just hoping for the best.

The Intelligent Prehab Loop

So assuming you buy the idea, how does it actually work in practice?

At A3, we break the intelligent prehab process into four steps: Detect → Forecast → Recode → Recalibrate.

Step 1: Detect – Deep Assessment, Not Vibes

The first step is moving beyond "I feel tight" or "my squat looks okay in the mirror."

We need actual data. That means comprehensive testing across three domains:

Mobility screening: Hip internal and external rotation, ankle dorsiflexion, shoulder flexion and rotation, thoracic extension, etc.. Not just "can you touch your toes"—we're mapping specific joint limitations that matter for your training and sport.

Strength balance testing: Left versus right asymmetries (is your right leg 15% stronger?), push versus pull ratios (are you benching twice what you can row?), quad versus hamstring balance, hip versus knee dominance patterns.

Movement pattern analysis: How you actually squat, hinge, lunge, press, and run under load. We're looking for compensations you can't see yourself—knees caving in, lower back taking over for glutes, shoulders hiking up during presses.

Depending on the client and the context, we layer in force plates, motion capture, and wearable sensors for more objective data. But regardless of the tools, the core principle is the same: you need a map of your specific fault lines, not a generic "strengths and weaknesses" printout.

The output of this phase is a detailed profile: here's where you're tight, here's where you're weak, here's where you're compensating, and here's how all of that interacts.

Step 2: Forecast – Backcasting From Failure Modes

Now comes the interesting part: connecting your specific data to likely injuries.

This is where we explicitly backcast. We ask: "Given this pattern—tight hip flexors, limited hip extension, weak glute medius, valgus collapse in single-leg tasks—what injuries has this profile predicted in people like you?"

This is also the step where we bring in our proprietary A3 AI system, to help us juggle—and find patterns in—more extensive amounts of data than even great coaches can keep in their brain at one time.

We built this part of our artificial intelligence system based largely on three main bodies of information:

1. Historical datasets: What happened to other athletes, executives, and weekend warriors with similar profiles?

2. Research literature: What does the science say about risk factors for specific injuries?

3. Pattern recognition: Machine learning models that flag combinations of variables humans might miss (for example, the interaction between limited ankle dorsiflexion and knee valgus in predicting patellar tendinitis).

Now, we can feed a client's detailed data in, and kick a hyper-personalized risk profile out.

Risk profiles aren't about scaring you. You're not 'broken.' But they can tell you that you're facing increased odds of knee pain or IT band issues or elbow tendonitis in the next 12-24 months unless you change the way you move and train.

Step 3: Recode – Training as Preemptive PT

Armed with that profile, an intelligent approach to prehab diverges starkly from the standard model.

Our "prehab" doesn't live in some separate corrective exercise corner of your program. It doesn't happen in a 10-minute pre-workout activation circuit. It becomes the spine of your entire training plan.

That means:

Main lifts chosen to address deficits. If you have a significant left-right strength asymmetry, swap out some of your bilateral barbell squats for split squats, single-leg RDLs, and other unilateral work to close the gap.

Accessory work targeted to your specific deficits. If your glute medius is weak and your hip external rotators are underperforming, load those split squats and SLDLs in a variety of ways to change the force vectors, or supplement with things like curtsy lunges and Copenhagen planks—not just because they're "good exercises," but because they're solving your problem.

Warm-ups matched to your pattern, not random stretches. Similarly, if you show limited hip internal rotation and compensate with lumbar rotation, your warm-up might include specific 90/90 hip internal rotation drills and motor control work—not generic leg swings.

Unlike 'traditional' PT, we aren't sidelining you to just light bands and pink dumbbells; you'll still be training, hard. But you'll be doing so in a smarter way, rebuilding the foundation so you can keep training (and playing) hard for decades to come.

Step 4: Recalibrate – The Feedback Loop

And, finally, we check our work.

This approach doesn't work as a "set it and forget it" protocol. Every 4-8 weeks, you'll need to re-test key metrics:

• Has hip internal rotation improved?

• Are left-right strength gaps closing?

• Has your squat pattern cleaned up on video analysis?

• Are the risk markers trending down?

As those numbers improve, the program evolves. You keep knocking out low-hanging risks, while also focusing increasingly on offensive, performance-building work.

The loop is continuous. Assessment → forecast → training prescription → reassessment. It's not a one-time fix; it's an ongoing system of intelligent noise-canceling for injury risk.

Two Red Zones You Probably Have Right Now

Our work at A3—whether through our Outperform Coaching program or in-person at our Reboot Performance Lab—is based entirely on hyper-personalization. Every person, and every person's collection of movement patterns, is unique.

But, after hundreds of clients, we can also say that at least some of those movement patterns show up nearly universally, at least in the highly-successful desk-jockey demographic that makes up most of our client base.

In future posts, we'll circle back to deep-dive those patterns one by one—giving you a set of tests to confirm they apply, and then both a general framework and some specific movement and exercise ideas to bake into your program if they do.

Until then, we'll start by running quickly through two of the most common 'red zones' we see, to give you some immediately actionable food for thought.

Red Zone #1: Desk Warrior Hips

The pattern: Tight hip flexors + weak glutes + weak external rotators

Odds are, you do a pretty impressive amount of sitting: you sit on the way to and from work, you sit at your desk and at meeting, you sit at restaurants and at your dinner table and on your couch. All-in, you're likely sitting for at least 6-8 total hours over the course of your day.

If so, this one almost certainly applies.

What it looks like:

• Chronic low back tightness (especially after sitting or first thing in the morning), with occasional low back pain (sometimes acute / 'back going out').

• Knees cave inward during squats or lunges, especially with more load / speed.

• You feel your quads and lower back way more than your glutes when you deadlift or squat.

• Often, knee pain (usually on the opposite side of your dominant hand—if you're a righty, that's left knee) that comes and goes without obvious cause.

What's actually happening: Your hip flexors adaptively shorten from all that sitting. Due to something called 'reciprocal inhibition,' your glute max stops firing, which drags your glute medius and the hip external rotators down in turn. When you try to move, your body finds workarounds: your lower back hyperextends to make up for limited hip extension, your knees collapse inward because your glute med isn't strong enough to stabilize laterally, and your hamstrings and lower back take over to cover for all the work your glutes should be doing.

Why this matters: Your hips are the engine of nearly every athletic movement—running, jumping, squatting, hinging. When they don't work right, everything else breaks down. This pattern is a direct line to non-specific low back pain, hamstring strains, IT band syndrome, patellofemoral issues, and more

The backcasting question: If we assume you're going to develop one of those injuries in the next 18 months, what would we find today? Probably exactly this pattern.

What intelligent prehab looks like:

A quick self-check: try the "couch stretch." (Make sure you get your rear knee and rear foot flush against the wall.) If you can't get to a vertical torso with your other foot flat on the front (and the majority of our incoming clients can't even get that foot up to the ground in first place), you're hit.

If so, your training emphasis shifts:

• Main lift focus: Split squats, single-leg RDLs, hip thrusts, step-ups

• Accessory work: Lateral band walks, fire hydrants, Copenhagen planks, 90/90 hip stretches

• The key: You're not just "doing glute work"—you're specifically targeting the lateral stability and external rotation that's missing

Future deep dive: In our next article, we'll walk through the complete hip assessment protocol and the six sub-variants of this pattern based on which specific hip rotators are involved.

Red Zone #2: Keyboard Shoulders

The pattern: Tight internal rotators + weak external rotators + weak mid-back

You also probably spend a bunch of your day rounded over like a giant prawn, with your hands close together in front of you. You're typing on a keyboard, scrolling on your phone, or shoveling food into your mouth.

What it looks like:

• Rounded shoulders and forward head posture (take a side profile photo at your desk—you'll see it)

• That "pinchy" feeling at the top of your shoulder during overhead presses or pull-ups

• Shoulders hiking up toward your ears when you press

• Chronic neck tension or tension headaches at the end of a long work day.

What's actually happening: Your chest, front delts, and internal rotators are locked short and dominant from internal rotation. Your mid and lower traps, rhomboids, and external rotators are weak and inhibited. Your scapulae don't move properly—they wing out or tip forward instead of gliding smoothly. When you try to press or reach overhead, your rotator cuff tendons get pinched between bones because the scapula isn't creating space.

Why this matters: The mid-back and scapular muscles are what stabilize your shoulder complex during any upper body movement. When they're weak or not firing, those tiny rotator cuff tendons take the entire load. That's the classic setup for impingement, tendinopathy, and that nagging "angry shoulder" that makes bench presses or pull-ups miserable.

The backcasting question: If you develop rotator cuff pain in the next year, what pattern would predict it? This one.

What intelligent prehab looks like:

A quick self-check: Try a wall angel (back against wall, try to slide your arms up overhead while keeping your elbows and hands in contact contact with the wall). Then try an Apley scratch—reaching your hands together behind your back with one arm reaching up your back and the other reaching down behind your neck. Can you clasp your hands behind your back? Does one side look or feel way different than the other?

If those reveal issues, your training emphasis shifts:

• Main lift rebalancing: Your horizontal pulling volume (rows, face pulls) needs to be at least equal to—if not greater than—your pressing volume

• Accessory work: Band pull-aparts, face pulls, YTWs, rotator cuff external rotation work, thoracic extensions over a foam roller

• The key: You're not just "strengthening your back"—you're restoring the specific scapular control and external rotation capacity that your posture has stolen

Future deep dive: We'll unpack the full shoulder assessment and rehab protocol in a follow-up article, covering all 17 muscles and 4 joints involved in healthy shoulder mechanics.

AND ONE VERY IMPORTANT CAVEAT: These are high-level patterns, not personalized prescriptions. They're useful as a starting point for self-awareness, but they're not a substitute for actual assessment. Your specifics matters—where exactly you're tight, which muscles are weak, how your compensation patterns interact. That's where the real magic of intelligent prehab happens.

Stop Training Toward Your Next Injury

Here's the bottom line: you're already training. The question is whether you're training toward your next injury or away from it.

Most people wait for catastrophe. They ignore the warning signs—the tightness, the asymmetry, the weird compensations—until something breaks. Then they finally get the sophisticated analysis they should have gotten 18 months earlier.

You don't run your business that way. You model risks. You fix small problems before they become existential ones. You build redundancy into critical systems.

Your body deserves the same analytical rigor.

Intelligent prehab—using backcasting to predict likely injuries from current imbalances, then building training around prevention—isn't complicated. The technology exists. The methodology is proven. The only question is whether you'll apply it before you need it, or after.

The patterns we discussed—desk warrior hips, keyboard shoulders—are a couple of potential starting points. They're useful for self-awareness. But true intelligent prehab requires personalized data: your specific movement patterns, your unique asymmetries, your injury history and training goals.

Generic advice has limits. Specific intervention has power.

If you want to see what intelligent prehab looks like in practice—the full assessment, the backcasting process, the personalized training protocols—that's exactly what we do at A3.

The best time to prevent an injury was 18 months ago. The second-best time is today.

Stop waiting for your body to fail before you intervene.

--

Josh Newman is founder and CEO of A3 Health. He has spent nearly three decades founding and scaling companies in technology and high-performance physical fitness, and holds a dual BS in Neuroscience and Computer Science from Yale University

Take it Easy! A simple workout for your least motivated gym days

While both weight lifting and high intensity Interval training (HIIT) have huge health and fitness benefits, some days they just feel too daunting.

Here's an easy, non-scary 30-minute workout that’s perfect for days you just want to check the “I worked out” box while still making a meaningful impact on your health. (It counts as Zone 2 cardio, and it’s a great way to burn fat.)

1. Set a treadmill to a 12% incline.

2. Get on and start walking. (If you're in decent shape, ~3mph is a reasonable place to start.)

3. If you're feeling saucy, increase the speed a bit; if you're feeling tired, decrease it. Keep inching the speed up and down over the 30 minutes based on how you're feeling.

4. To get the biggest fitness bang for your buck, try to do it without holding onto the rails; if you need to hang on them, you're probably going faster than you can handle, so decrease the speed instead.

At the end of 30 minutes, write down the distance you covered.

The next time you do the workout, your goal is simple: go at least .01 miles further than you did the last time.

Non-horrible enough to do on even your least motivated days. But still effective in helping you progress your fitness and health. 💪

Walk it Off—How to Gamify Increasing Daily Steps

We all know walking more is a great way to improve health and drop fat.

But most of us walk only about half the steps needed to minimize all-cause mortality.

Here's an easy way to gamify walking that has consistently worked for our clients:

1. First, check your phone's step count from yesterday. (You'll find it in the Apple Health app on iPhone, or in the Google Fit app on Android.)

2. Today, your goal is simple: walk at least one more step than yesterday.(E.g., if you walked 4,319 steps yesterday, you're gunning for at least 4,320 today.)

3. Then try to inch the number up further tomorrow. And again the day after.

4. If you fall short, no worries! Just start the process afresh the following day, trying to beat the new lower number. (E.g., if you're aiming for 12,245+ steps today, but only clock 6,312, tomorrow you're just looking to hit 6,313+.)

The only real rule: don't miss two days in a row.

Extremely simple.

But our experience shows, it really works.

On a GLP-1 drug? Here’s how to drop fat *and* maintain muscle.

If you’re on a GLP-1 agonist (Ozempic, Wegovy, Trulicity, Mounjaro, etc.), odds are you’re not just losing fat, but muscle, too.

We’ve helped a ton of clients on GLP-1 drugs drop fat while maintaining muscle.

Here are some of the strategies that have mattered most. 👇

1. Lift like a bodybuilder.

Normally, we take a functional approach to workout programming: training in the gym so you can do stuff in the real world, now and for decades to come.

During rapid weight loss, however, our priority is first and foremost just maintaining (or even gaining!) muscle.

Some of what that entails:

• Using higher rep ranges.

• Taking sets closer to failure.

• Increasing volume (whether sets per movement, movements per body part, or total weekly volume).

• Focusing on tempo, with longer eccentrics.

• Incorporating a wider variety of exercises for each body part.

• For less experienced lifters, using machines more frequently (so we can safely load heavily, instead of spending the first months focusing on mastering movement patterns with lighter weights).

Once clients hit their weight loss goal, we can then move to a broader focus, factoring back in performance, injury prevention, and long-term health.

But during that initial stretch of GLP-1-aided fat loss, we make hypertrophy (maximizing muscle) the primary goal.

2. Prioritize Protein

Research makes clear that protein is particularly important for maintaining muscle while losing fat.

However, most of our clients come in the door already under-eating protein, even before factoring in increased needs during weight loss.

And because GLP-1 drugs make people less hungry, we often see that low protein intake going further down just when it most needs to go up.

Countering that is totally possible; it just takes concerted effort.

In particular, we recommend:

• Making sure protein is a priority at every meal.

• Focusing on leaner proteins, which pack more grams of protein per ounce.

• Finding less satiating forms of protein (like protein shakes) that clients can wedge in between meals.

• Keeping easy, high protein snacks on standby.

That said, it’s also important to make sure you’re taking in enough carbs, fats, and micronutrients to keep fueling healthfully overall.

3. Get more sleep.

A ton of research has highlighted the importance of sleep quality and quantity for muscle gain and maintenance.

If your sleep isn’t a priority, make it one.

If your sleep isn’t as good as you’d like — if you have trouble falling asleep, staying asleep, or wake up still tired despite enough hours in bed — that’s a solvable problem.

Sleep is too complex to cover well in just one post. Suffice it to say, it’s more under your control than you might think. If your sleep isn’t great, it’s worth digging in to find the specific changes that work for you.

4. Go slow.

We all want results, fast.

And for many clients who’ve previously struggled to lose weight, finally seeing change with the help of GLP-1 drugs is an even bigger push to lose weight as quickly as possible.

However, there’s an inverse relationship between speed and quality of weight loss. The faster you drop pounds, the higher the percentage is likely to be from muscle.

For a quick and dirty rule of thumb, limit weight loss to ~0.5% of body weight per week.

Even if that adds a few months to your weight loss trajectory, it will pay dividends in retained muscle mass for decades ahead.

5. Measure what matters.

Most of us are terrible at objective self-assessment, and are even worse when that’s combined with (very common) body dysmorphia.

Pair that with how hard it is to notice gradual change, and it’s basically a losing cause. You’re just not going to be able to look in the mirror and accurately judge your progress.

Scales can tell you how much weight you’ve lost, but not what percentage of that loss is fat versus muscle. You’ll need to use DEXA scans, BIA, calipers, or similar tools to get a more accurate picture. And, ideally, you’ll need to use them regularly.

If you’re on track at each step along the way, odds are obviously much better you’ll end up where you want.

And if things aren’t going exactly to plan, more accurate data will help you adjust as needed, to get back on the path before you veer too far off.

6. Leverage outside experience.

You don’t need to reinvent the wheel here. Experienced coaches who have worked with people in your situation can help you get the results you want.

Learning lessons second-hand from others’ experiences definitely beats having to muddle through the same ones blindly yourself.

Especially during a long, slow, gradual process of change, there’s huge value in having outside advisors who can provide perspective, support your progress, and celebrate victories along the way.

TLDR:

GLP-1 drugs are powerful new tools.

If you decide they’re right for you, just make sure you pair them with smart lifestyle choices around exercise, nutrition, and sleep.

That’s likely to make a difference to your fitness and health, both in the immediate future, and for decades still to come.

p.s. Take a look at the header image for historical data from one of our clients, Mike, who’s dropped a ton of weight while retaining muscle. We know you can do it, because we’ve seen it happen, time and again.