Exercise, VO2 max, and longevity | Mike Joyner, M.D

Right, so from a practical stand point that includes the nuance. Let’s take two athletes training for a 5k run, which is a largely VO2 Max based distance.
Athlete A: Decides to only do interval training 4 times a week.
Athlete B: Decides to run 7 days a week, 2 of the days are intervals, and on the weekend they do a longer than normal effort in zone2. The other 4 days are easy 45min - 1hr sessions to keep base.

Which athlete ends up with a higher VO2 max? It’s athlete B every time.

One of the key nuances is that HIIT is hard on your body. It beats up your CNS and fatigues you more. So, you can’t get as much adaptation. Eventually/Often it even causes injury.
Easy walking, rucking, swimming, cycling offers numerous benefits including VO2 max. You’re less likely to get injured, you can get out in nature which has significant lifestyle benefits, it’s also a form of meditation.
HIIT only isn’t in my opinion all that sustainable and you can’t get to the same VO2 max levels as athletes who can put in way more work at lower intensity levels.
I feel like in todays debate society it’s always an either/or. Nuance explains the why for both and encourages the reason for both.
In my original post I said I love HIIT, and I do. But I stand strongly by the statement that zone 2 training is the foundation for a good VO2 Max.

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I still like the pyramid analogy – Zone 2 for the base, VO2max for the height. Big pyramid good :slight_smile:


yes but if you are time crunched and general aerobic fitness is what you are after Z2 is a waste of time and you are better of doing Z4 or 5 intervals. Zone 2 isn’t your base of the pyramid, it’s window dressing to get in more volume if you want to become a better endurance athlete with lots of time on hand @Davin8r

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What would that look like? Could you give some examples…

Z4 is maintaining HR in zone 4? Is there any tricks in calculating zone 4 HR or can I approximate with my apple watch data?

How would intervals look like?

Coggan recommends going as fast as you can for 20 minutes (after an anaerobic clearing effort) and taking 95% of the average power of that 20 minute interval. That value is your FTP. He recommends 95-105% of that effort for Z4 and 106-120% for Z5 work. But that’s for cycling, I don’t run…but I don’t think the fundamentals of the physiology are different. Z2 for time crunched people that don’t want to compete but just be generally aerobically fit is a waste of time. If you want to compete in some 4+ hour endurance event than of course it’s different…

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We’ll have to agree to disagree on this one. Maybe if you had to choose one vs the other due to strict time constraints, but otherwise for optimal fitness and health I’d absolutely emphasize both.


Something I think gets lost in the debate, is the ramifications of your lifestyle if you’re so time constrained that you can’t do both. We’re talking optimal longevity, which I personally adhere to a more balanced lifestyle between family/work/exercise.
That’s something I really appreciate about Alan Couzens, is he regularly discusses the balance. Stress from life/work can limit your exercise gains. If lifestyle is constraining your time to where you can only do a few HIITs a week, what does that mean for your CNS?
I agree with @Davin8r here. If you have to choose one, then yea choose a few HIITs a week. Hopefully you don’t have to make that choice.
Get out and take a hike in nature, take a long bike ride, walk the dog, do some yoga. Ideally you want to move a few times a day and get that heart rate up into zone 1 or 2. Those gains contribute to your VO2 Max and longevity.


@RapAdmin I stumbled across an older article that I read from time to time that does a good job explaining the relationship of regular movement and your VO2 Max.

If you haven’t read it yet, take a gander and enjoy!


But also…HIIT appears to shrink atherosclerotic plaques:

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If I read this correctly, @LaraPo , the researchers measured blood plasma levels before and after 45 min of exercise. It wasn’t a long-term look at whether exercise benefits immune function or not over a longer period than a few hours. Is that what you saw?

I don’t see a lot of super muscular old people (and no old fat people, as the joke goes), but I might suggest huge muscles on men and women (and very muscled old people) is a relatively new development. Huge muscles seem like they are produced instead of very strong, smaller dense muscles. The super muscular old people I do see (Dr Jeffrey Life?) seem like they are in pretty healthy shape with great “healthspan” and capabilities, and they generally move like a much younger person (which implies something internally about it is a positive). But maybe the longterm MToR activation and protein synthesis outweighs the benefits. I know there was the post a few days ago going over a BMI versus overall mortality which suggested even muscled people are at a disadvantage for mortality, and BMIs in the 18.5-20 are ideal. Im 53 so I’m making the bet I will need some level of muscle to have a great healthspan, and I can lean out later (possibly) if this turns out to be important. I’m not damaging my cardiovascular system as much as via intense endurance sports, and I do cardio (stairs and walking) regularly so ideally I’m not too much of one thing to miss out on some extra longevity.


I need to increase my workout schedule…


What about using drugs for VO2 Max? EPO? I don’t know anything about it, the risk vs. reward, etc…

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Do you know what is meant by intensity factor 0.7?

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I posted a little about this here: Exercise, VO2 max, and longevity | Mike Joyner, M.D - #74 by RapAdmin

But fundamentally, from my reading of it, EPO just provides a temporary boost to Vo2 Max and performance while you are taking the EPO. And there are longer term issues (though I’m sure its not well researched, and dosing levels are not varied / tested to optimize outcome for Vo2Max/performance, etc.).

I was thinking something like EPO might be able to be used to increase your Vo2Max, which would allow a higher level of exercise than you normally do, and then perhaps you could maintain that Vo2Max long-term with just the exercise and phase out of the EPO. It would be great if you could use it as a means to improve your cardio performance and leverage yourself up to a higher baseline, but I’ve seen no research that this is the case. Its just used for short term performance enhancement while you are taking EPO. Thats not what I’m looking for. (but I may be wrong - I have not dug deep into the literature, that is my initial reading of it).


Good question - I didn’t know either. This is getting deep into the weeds of exercise physiology it seems…

Here is what I found:

Abbreviations and Terms used in this article

  1. FTP – Functional Threshold Power, an approximation of the maximum power you could sustain for an hour
  2. NP – Normalized Power, a mathematically adjusted measurement of average power that smoothes out power spikes and coasting
  3. IF – Intensity Factor, a measurement of how intense a workout is, relative to your FTP
  4. TSS – Training Stress Score, a measurement of the overall training effect of a workout
  5. Workout Levels – a new metric in TrainerRoad that ranks workouts on a 1-to-10 difficulty scale, compared to other workouts in the same training zone.

Intensity Factor (IF)

Now that we understand normalized power, we can consider the simplest of the 3 metrics- Intensity Factor (IF).

As its name suggests, Intensity Factor reflects the relative intensity of a workout. To calculate IF, simply divide your workout’s Normalized Power by your FTP. A workout with a normalized power equal to your FTP will have an Intensity Factor of 1.0.

IF can be a useful way to quickly judge a workout’s difficulty. The closer a workout’s Intensity Factor is to 1.0 or above, the more intense it is likely to feel. But there is an important caveat- Intensity Factor measures intensity against your FTP, and your FTP represents the power you can theoretically generate for one hour. IF does not incorporate your power curve or adjust for how your ability to generate power changes over differing durations.

This means short workouts can have Intensity Factors well above 1.0 without actually feeling overly intense, since it’s fairly easy to ride above FTP for short periods. It also means long workouts may be all-out efforts relative to their length but have intensity factors that seem deceptively low, as it’s almost impossible to ride at FTP for much more than an hour. As a result, IF is most clearly insightful for workouts of an hour, and less so for longer or shorter rides.

Source / More details: TSS, IF, and Workout Levels: 3 Metrics to Help You Understand Your Training And Get Faster - TrainerRoad Blog

Related: https://help.trainingpeaks.com/hc/en-us/articles/204071944-Training-Stress-Scores-TSS-Explained#

Related: What Is Intensity Factor on My Garmin Fitness Device? | Garmin Customer Support.


Didn’t know if this should go into the Urolithin A thread or this one. Often Urolithin A is touted as improving VO2 max, which according to the paper was by about 10% over placebo (in the 1 g group). But, for the subjects they chose it seems that they were all highly sedentary people with a VO2 max percentile rank of about 2%, which correlated to only 23 mL/kg/min. Anyway, I found this a bit disappointing. It would be good if they tested it in regular exercisers that already have decently working mitochondria.




Yes, one other thing in common. Both had $ millions to spend on healthcare and concierge medical attention from the best available in the US.

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Interesting that the guy that invented FTP, NP, IF and TSS (exercise physiologist Andrew Coggan) frequently posts on the trainerroad forum that Couzens is clueless on basic physiology…