human performance coach | coordinated perspective | coach
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Breathing Gears System update:
Blog on Athletic Breathing and my experience on over a decade of work on this: shiftadapt.com/athletic-brea…
Breathing Gears System update itself: shiftadapt.com/the-breathing…
*much more work to do, and details of Art of Breath BGS detailed course coming.
@DrAndyGalpin @hubermanlab
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A lot of men we see snore through bad sleep, and a fair number of them end up with a sleep apnea diagnosis. They train hard, work hard, sleep poorly, and wake up exhausted. This is largely a fitness-related issue, with organizational and metabolic limitations. Poor organizational skills = breathing compensations; poor metabolic function has higher-than-normal respiration rates. Low metabolic health carries >sympathetic tone & lower HRV. When it comes to sleep, these folks end the day exhausted, fall asleep, but never recover from the lack of quality and the demands of the day. Build the lower end and learn to organize by understanding the fundamentals vs. harder, more intense training.
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brian mackenzie retweeted
I ran into a mountain lion strolling down our street a few weeks ago. I can assure you my body knew the difference between it and an email notification.
Your body doesn't know the difference between a tiger and an inbox.
Every ping, every deadline, every late-night scroll tells it the same thing: danger, stay alert. Cortisol up, sleep down, belly fat on.
Then you stand at the edge of the sea for ten minutes and something switches off.
The sound of waves. A wide-open horizon. Nothing to answer, nothing to fix.
Our ancestors lived with real danger, but they also had long stretches of quiet. We've swapped those for a phone that never stops.
You can't out-supplement chronic stress. No magnesium, no adaptogen and no breathing app replaces simply going somewhere wild and doing
Share this with someone who's running on stress and caffeine.
Where do you go when your head needs quiet?
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A lesson in how we think and reality.
If you believe (think) that an email can give off the same information as a tiger you’re dealing with a mind limitation.
Your body doesn't know the difference between a tiger and an inbox.
Every ping, every deadline, every late-night scroll tells it the same thing: danger, stay alert. Cortisol up, sleep down, belly fat on.
Then you stand at the edge of the sea for ten minutes and something switches off.
The sound of waves. A wide-open horizon. Nothing to answer, nothing to fix.
Our ancestors lived with real danger, but they also had long stretches of quiet. We've swapped those for a phone that never stops.
You can't out-supplement chronic stress. No magnesium, no adaptogen and no breathing app replaces simply going somewhere wild and doing
Share this with someone who's running on stress and caffeine.
Where do you go when your head needs quiet?
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Two people can carry the same VO2max and run on completely different fuel. Fitness and body composition explain part of how much fat someone can burn, and the rest comes from how they've moved and lived. So while someone may be lean and muscular, paradoxically they can be unable to support themselves well for long beyond a walk. One of these VO2 Maxes deteriorates far faster than the other.
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Burning “sugar”, while a natural transition under stress, produces about 43% more CO2 per unit of oxygen than burning fat, and CO2 drives most of our breathing through the brain and nervous system. Someone running on sugar breathes harder for the same work, and we see it all the time in fit, stressed athletes.
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The body treats work close to your limit as stress. Where’s that limit? Easy, where the SNS takes over. That's just outside an aerobic threshold. So someone living near theirs runs more adrenaline through an ordinary day than someone with room to spare, while blood pressure and heart rate climb with it. Not to mention the slower or delayed clearing of the metabolites associated with said stress; recovery.
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Testosterone works a bit like a mute button on stress. Every male I’ve seen on TRT sits below minimum metabolic standards, with lower heart rate variability, and the fatigue it masks still runs through their nervous system and metabolism. They lack the infrastructure for the stress levels they demand. While TRT can be life-changing for many, what I’ve seen is that "life-changing" often means letting the behavior that burnt the house down continue while muting the signals and avoiding the behavioral changes that would actually build the foundation to support the demands put on them.
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Walking costs oxygen, and that cost barely changes from person to person. The ceiling above it changes a lot. With a VO2max down around 15 to 18, close to the floor for living on your own, a walk to the mailbox eats 70 to 90% of everything you have. We see this in the elderly all the time. So why is VO2 Max important? It’s not really, as it is a proxy for activity levels. Those who are highly active (well above norm) their entire lives maintain a high VO2 Max, and it deteriorates far more slowly than in people who are average or worse, totally sedentary. So, while we see this by measuring VO2, the reality is those who move more and remain active their entire lives suffer less.
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You can be relatively healthy and still struggle with basic physical activity if you aren't really fit. Fit means being able to support your body at a basic, metabolically functional level. This is the person whose blood pressure struggles going up the stairs, whose breathing changes significantly by 2 flights. Or just avoids the stairs altogether.
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brian mackenzie retweeted
My son, Grayson, wrote a book for parents about young athletes, and it challenges how we think about supporting our kids through sport.
It’s called Dear Parent: Sport Isn’t Easy. Here’s How to Have Our Back. Eleven chapters… tough teammates, coaches who get something wrong, and what a club sport actually costs in time and sleep. Each one is a story, what he took from it, and something a parent can try that week.
Those of us with kids in youth sports know what the experience gives them... teamwork, commitment, the skill of balancing a full week. We have come at that subject often on this podcast, usually through the lens of the coach, the parent, or the research. This one comes from the kid’s angle, from the court, the car ride home, and the receiving end of those parent-child conversations.
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PR’d a 10 Mile trail run and back squat (350 range) in same day (2010ish).
Programming matters. 4 long-interval HIIT per week is a blood sacrifice, not programming.
A while back, @hubermanlab tagged me in a post asking “can you get strong and fast at the same time?”
Tl;dr: Probably, though not always. But it's not because cardio "kills gains."
The best example of this comes from a 2026 study.
Two groups did the exact same lifting program for 16 weeks. One also did 4 long-interval HIIT sessions a week.
Muscle fibers grew the same (~19% vs. ~18%), protein synthesis rose the same, but leg press strength gains were blunted by about 40% in the group that added intervals! That was in the context of an 11% bump in peak aerobic capacity.
So cardio didn't stop muscle growth, but it did cost max strength.
I think it makes sense that the “tradeoff” would manifest at the level of functional performance, for those concerned. If endurance work is borrowing energy from quality strength work, you won’t optimize the latter (and vice-versa).
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brian mackenzie retweeted
Hello, @brianmackenzie — this is exactly what happened to me as a recreational road runner in the first part of 2026, when my VO2 max suddenly fell from 64 to 54 due to inactivity. As soon as I became active again, it slowly started to rise.
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In the big US treadmill registry, the top tenth of men in their 40s reach a VO2max of 52.1 mL of oxygen per kg per minute or more, above the typical man in his 20s, and the top tenth of women in their 40s sit above the typical woman in her 20s. Men and women in that top tenth are the ones who stayed active. For small groups of men who kept training for years, the loss ran about 5% a decade. A 40-year-old holding a 50 who keeps training most weeks is likely to keep his mobility into his 80s, while a 20-year-old at 48 without the activity habit is unlikely to be mobile enough to support themselves in their 80s
ALT Graph of VO2max by age for men and women, typical value and top tenth, Kaminsky 2015 FRIEND registry
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That steep drop makes the VO2/activity level someone has when it starts the thing that decides how long ordinary movement stays easy. People build that level in midlife, by how much they move.
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Sources: Percentiles by age and sex, Kaminsky 2015, FRIEND registry, Table 3. pubmed.ncbi.nlm.nih.gov/2645…. Loss of about 5% a decade in men who kept training, Kasch 1995. pubmed.ncbi.nlm.nih.gov/7552… Rogers 1990. pubmed.ncbi.nlm.nih.gov/2361… Average drop past the 70s, Fleg 2005. pubmed.ncbi.nlm.nih.gov/1604… Wilson and Tanaka 2000. pubmed.ncbi.nlm.nih.gov/1071…
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The larger the person, the more CO2 they will produce. The more metabolically unwell the person is, the more CO2 they will produce. The more stressed (higher arousal, emotional) a person remains, the more CO2 they will produce.
The NS responds appropriately to the signal by increasing activity by lower HRV, + respiration rate, + BP, + glucose, or + SNS activity that it establishes a new base to. The endocrine system follows the instructions of the NS; thyroid, testosterone, etc all begin to down-regulate. The system is exhausted.
We can run decades like this until the wheels begin fall off. The patterns are so ingrained by this point people would rather die than learn to swim.
This is fascinating.
Human *metabolic* CO2 production almost doubled over the last 30 years.
60% is attributable to population growth, but the other 40% might be the most interesting.
Humans getting a lot bigger and fatter certainly comes into play, but metabolic health likely does as well.
Recall...
CO2 produced = TEE x RQ / EE of O2.
That is, as RQ (Share of energy coming from carbohydrate) goes up, like an inefficient factory spewing noxious gas into the atmosphere, your CO2 production also goes up! 🏭
So, for the sake of the planet 🌎...
Stop being a fatass. Get your metabolic health in order.
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