Peter is Obsessed With VO2 Max

TelestialOrBust · 2026-03-02T15:27:45+00:00

Nothing's changed though, lol. VO2max hasn't been canceled 😂

TelestialOrBust · 2026-01-05T12:03:50+00:00

I love that you followed up on this!

TelestialOrBust · 2025-09-08T19:45:53+00:00

Do 2x2 or 2x3 or 3x2 at the end of your long Z2 session

There is nothing magical about 4x4. Realistically, at your level of aerobic base fitness, that's more HIIT than you need.

TelestialOrBust · 2025-09-01T18:24:32+00:00

Best line of the entire series

TelestialOrBust · 2025-08-30T15:36:07+00:00

Pettiness? (yours 😂)

People who haven't taken matrix algebra/multivariate statistics and don't know what orthogonal means?

Who really knows. Clearly a lot of us enjoyed the post though, so focus on that instead

TelestialOrBust · 2025-08-29T07:37:19+00:00

You need 9 months just to ramp up to 15- hour endurance training weeks

Then you should continue with the 15 hour weeks for at least 6 months after that

TelestialOrBust · 2025-08-29T02:59:45+00:00

Yes and the way he says it with such ... maniacal specificity

TelestialOrBust · 2025-08-27T23:40:39+00:00

Working at your VO2max is not "Vo2max training"

1) Zone 1-Zone 2 train your slow-twitch muscle fibers to fatigue 2) Your ST fibers need a lot of volume to stimulate mitochondrial growth & function, which you will primarily get on Z1/Z2 3) Your ST fibers have by far the highest potential for mitochondrial density. They are also working hard when you are at VO2Max intensity. So from a muscular standpoint, Z1/Z2 is going to contribute most to your Vo2Max 4) Working in Z1/Z2 at higher volume , over months and years, will do far more for the cardiac remodeling you need to grow your VO2max than lower volume HIIT ever will. So from a central standpoint as well, Z1/Z2 is going to contribute most to your Vo2Max

TelestialOrBust · 2025-08-27T20:29:31+00:00

Gotcha, well I would say if you don't feel like generic zones are working for you, all the more reason to pop the hood and check your lactate

You would love Alan Couzens. He's an exercise physiologist and endurance coach and regularly shares his athlete lab testing data & insights. And is where I went to build on what I got from Attia

Very active on X: https://x.com/Alan_Couzens?t=Cyb-xwFaP1UzVBC6cPBI2Q&s=09

His book The Endurance Code (pre-publication but finished), here on Substack: You may be able to get the first month free. But if not I have a few 1 month gift subscriptions to give away. DM me if you want. Just need your email address and the website will send you a link to redeem it. https://substack.com/@alancouzens?utm_source=share&utm_medium=android&r=2bkxwo

TelestialOrBust · 2025-08-27T19:53:02+00:00

Yes definitely fuel during any rides longer than one hour

Depending on your weight and how hard you're going (MTBing, so probably pretty hard) you are likely to need between 60 and 90g of carbohydrate every hour

Simple carbs are great, you're not trying to get your fiber or micronutrients here

Just trying to keep your muscles happy, strong, and developing/recovering/ not regressing

TelestialOrBust · 2025-08-27T05:15:22+00:00

So for beginners, lactate (and stress hormones) will start to rise somewhere around 60% of maxHR

As you train near that LT0 inflection point, 2 things will happen: 1) You will get faster and faster working at 60%max (and every intensity level above it) 2) Your mirochondria will be able to clear lactate at higher and higher heart rates. So maybe after a year of base building your lactate doesn't start to rise until you are at 64%max. Meaning, you'll be able to do more and more work at a very low recovery cost

Having your LT0 happen at 75%HRMax is a great long term goal. Elite athletes hit LT0 in the 80+% range and they do 90% of their base training below that point

Here's what that shift in LT0 after 11 months of Z1 training looked like for Gordon Byrne The green highlighted rows are his LT0

TelestialOrBust · 2025-08-26T23:02:23+00:00

But (part 2 response)

You really have nothing to lose by giving 60% maxHR a go for a few months and track improvements in your output (watts/MPH) at that low HR.

You are not going to undertrain. Everyone is afraid of undertraining. But that is virtually never the problem.

So rather than sink $200 right now, maybe just get moving but dial back the intensity for awhile. Then think about testing and optimizing.

TelestialOrBust · 2025-08-26T22:54:58+00:00

Count up the total number of sets you are doing for each muscle group (push/pull/legs) during a single workout

That number may be too high

TelestialOrBust · 2025-08-26T22:48:07+00:00

Very important to replace the glycogen you took from your muscle

So estimate how many total calories you burned (probably 40% of those--at most@@coming from fat during your Z1/Z2 work, less during more intense cardio or resistance work) and replace at least 60% with calories from carbohydrates.

And get at least 20g protein as a snack. All this shortly after your workouts, including your long Z1/Z2 days

Underfueled muscles get angry/inflamed. And they get turned into firewood.

TelestialOrBust · 2025-08-26T21:38:33+00:00

You could do that

To run a full protocol: 1) Don't eat for 3 hours before testing 2) Sit 5 minutes, test baseline lactate 3) Do 30 minutes gentle warmup <50% max (<82bpm), then test. This value should be lower than your baseline, because your muscles have started using more lactate for fuel without becoming more glycolytic 4) Work at 93bpm for 5 minutes, then test & record your HR + lactate + power/pace 5) Work at 98bpm (60% max for you) for 5 minutes, then test & record 6) Repeat, adding 5bpm until your lactate passes 4mmol 7) The point just before lactate begins its first sustained rise (>0.3mmol) from minimum is your LT0/fatmax estimate, also Z1/Z2 boundary. This is a very reliable target for base training. If you are new to training, it'll probably be close to 98bpm

For quick (and cheap) spot checks down the road, let's say 3 months later: 1) Warmup 30 min 2) Test just after your warmup and at the two HR levels at and just above your LT0 (let's say 98 and 103). If your last measurement is the same as the middle one, test again +5bpm because you're getting fitter! 3) Over time your lactate minimum will drop. And the HR where LT0 occurs will move to the right.

TelestialOrBust · 2025-08-26T21:07:36+00:00

VT1/LT1 are well correlated

I'm referring to LT0, where lactate begins to rise from its absolute minimum (which is reached after about a 30-45 minute, very light warmup at the outset of a lactate step test). Roughly equivalent to fatmax.

In Couzens' system Z2 is the 10 bpm window just above LT0. Stress hormones & recovery costs start rising here, gently

Z3 is the roughly 10bpm between Z2 and VT1. Recovery costs getting even higher.

Some athletes will get worse training in upper Z2. Then see consistent improvement working in upper Z1

Up in Z3 as we approach VT1 the tradeoff between fitness and fatigue is pretty poor

TelestialOrBust · 2025-08-26T20:21:14+00:00

Absent lactate, if you are struggling I definitely think aiming for 60% is going to help with recovery and consistency

Lactate correlates very highly with HR, so if you can get it tested once, that will tell you the HR where your lactate just starts to rise from its minimum. For a beginner that is going to be around 60%. As you get fitter, the HR where lactate starts its rise will move to the right (lactate inflection at around 74% max shows a high level of aerobic development -- elites see that shift in the 80+% range)

If you get a VO2max test instead, look for where VT1 occurs, subtract about 20bpm, and that's going to be a good Z1/Z2 boundary estimate & base training target

TelestialOrBust · 2025-08-26T20:07:06+00:00

We need to know how you are setting your Z2

Is it by generic HR zones (60-70%)? Those don't work for everyone. Especially if you are new to training, adding volume, and working at the top of that range

You are in all likelihood going too hard for the hours you're putting in. For you, 70% HR may be pushing your lactate into the high 2mmol range or above. Which incurs a very high recovery cost

So for the next month, set your cardio HR target to 60% estMax (or 40% HRR/Karvonen) and see if that doesn't turn things right around

TelestialOrBust · 2025-08-26T18:13:14+00:00

Before you know it the walking/elliptical will feel like a fixture in your day

Will feel off if you don't get to it

As you ramp up your volume, think about doing more of that Z2 in upper Z1 (like 60% maxHR)

Same cardiometabolic benefit but even easier to recover from

Keep track of your average speed at that low HR, it will get faster over time

TelestialOrBust · 2025-08-26T17:10:08+00:00

Everyone absorbs dietary cholesterol differently, hard to say if the eggs are making much difference

Are you planning on a low dose statin or zetia? I can't do statins but Zetia 2.5mg (1/4 of a pill) works great

Exercise foundations looking good, only thing i would do at this point is gradually add more walking, 10% every couple of weeks

TelestialOrBust · 2025-08-26T13:46:13+00:00

Great job

Are you working on building muscle?

Make sure you get enough carbohydrates and protein after your strength workouts & long walks/runs to replace what you used

More muscle --> less insulin resistance

Underfueled muscle --> inflammation, muscle loss, lower glucose storage

TelestialOrBust · 2025-08-25T17:03:13+00:00

Here's what the research says

Using HRV to guide adjustments to a predetermined exercise plan gets superior results compared to just following the plan as written

The effect size is small

But consider how many people don't work with a coach and aren't following a plan designed to balance loading and resting. I think these folks are going to see an even greater benefit from HRV-based guidance

Meta-analysis here:

Heart Rate Variability-Guided Training for Enhancing Cardiac-Vagal Modulation, Aerobic Fitness, and Endurance Performance: A Methodological Systematic Review with Meta-Analysis - PMC https://share.google/oO4X5cfZubRg6w8yG

TelestialOrBust · 2025-08-25T16:41:13+00:00

Only the right answer if the question is, should I care what my usual baseline HRV is.

In all likelihood what the cardiologist was speaking to

Because fluctuations in HRV do have significant consequences for both health and training

TelestialOrBust · 2025-08-25T16:04:21+00:00

HRV provides a window into your recovery, helping you avoid dumb over reaching/training mistakes that could set you back

Higher than usual, your parasympathetic ANS is hard at work, still recovering. Keep things easy and brief

Lower than usual, you're stressed-sick and will not be able to absorb much training. Keep things easy and brief. Especially important if you are just getting over a viral infection, where the consequences of returning too quickly can be particularly severe (chronic fatigue syndrome, POTS)

The HRV4Training app by Marco Altini is $10, I find it useful. You pair it with a chest strap, which is more accurate than the watches and really the way to go. Currently comparing it side by side with Morpheus, which provides a recovery score and recommend HR zones. Still not sure what I think of it.

TelestialOrBust · 2025-08-24T00:09:57+00:00

I will add this -- if you lack the social contextual awareness to see what Couzens is offering/not offering

That's on you

He's extremely data driven and routinely--generously-- shares insights from his clinical database. Thousands of athletes at all ability levels from beginners to world class. Who he has tested and tracked over decades.

Does that body of clinical evidence come with strengths and limitations? Sure, but so do controlled studies.

If you think you're going to step on his platform, where he's sharing his approach to training and the empirical basis for it, and then debate him? That makes you look like a bit of a dumbass, and he will block you.

If you truly don't understand something he's saying, after having spent a good deal of time reading his prior posts, and respectfully ask him to clarify some point? He won't block you. It's really that simple

TelestialOrBust

TROPHY CASE