human performance coach | coordinated perspective | coach
Joined August 2009
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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
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.
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).
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.
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
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.
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…
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.
VO2 Max is a proxy for activity. Where that percentage of VO2 shifts from fat to carbohydrates (VT1) is a reality check into how much time one has or doesn’t before they begin to stop being as active. Thus loosing that VO2 max at a much faster rate as fitness drops and mass increases.
Being big or rich or famous isn't the problem. Each one tells you something real.
Breathing tells you something different, and it's hard to perform for an audience. At rest it shows what someone can actually support.
We use it because it's hard to fake. It doesn't answer everything.
Ancestral groups were small, so comparison had a small audience. Someone could look strong to the people who actually depended on them, and that meant something.
Vanity isn't new. What's new is how many people are watching and how often. I think we underestimate how much that changes things.
In young adults, heavy social media use goes with worse sleep. It probably runs both ways, since poor sleepers scroll more too. Either way it matches what we see.
The comparison keeps going after bedtime, and so does the demand it puts on us. Sleep is one of the first places the body pays for it.
I've met too many guys on CPAP machines who are training harder than they can absorb, to live lives they can't absorb. I think those two things are connected.
A lot of the same guys end up on hormone replacement, like their nervous and endocrine systems weren't part of the process the whole time. They were. In a lot of these cases the prescription is paying for how they've been living.
Bodybuilders report more muscle dysmorphia symptoms than other lifters. Maybe the sport builds it, maybe it pulls in people who already have it.
I don't read that as personality. I read it as behavior, and behavior is data. When the reward is how big we look, the training chases size and the mind keeps checking if it's enough. A reward like that never settles, so the checking never stops.
brian mackenzie retweeted
The healthiest, fittest people I know have one thing in common...
They consider their health and fitness in every major life decision they make.
* Where they work.
* Where they live.
* Who they spend time with.
* Who they marry!
* How they spend their free time.
Their fitness isn't so much about the training plan they choose...
It's about the life they choose!
Exceptional health and fitness don't just happen.
They're the sum of a lifetime of choices.