Vo2max adoption, power or HR?

Hello forum,
this is in regards to vo2max benefits.
This photo is taken from today’s session. As you can see, I have spent 10min within vo2max power zones, and 20min within vo2max HR zones.
the question is, when does the adoption happen? Is it based on power or HR? Did I spend 10 or 20 mins in vo2max zones??
Thanks in advance :metal:

Best answer: it depends. :roll_eyes:

What was your goal by doing the VO2 workout — training your oxygen capacity or training your power output?

If you were just doing the workout just because it was on your TR schedule, that’s also a very valid choice.

The TR VO2max workout prescribed at 120% will create adaptations for your power and your physiological process, but maybe not as good as training them separately. For most people they are a great bang for the buck.

I would say you got 20min of VO2 work via HR and less than 10min of VO2 power (the far right power bar is anaerobic…but that’s a different topic).


Curious what the reasoning is to know exactly. If your power on the bike is the focus, I’d only worry about power zones. Heart rate has so many reasons it could be elevated or lower from one session to the next.

What does training the HR zone get you in the scheme of getting faster? Training HR zone is for base building, training power zone is for specialising?

For targeting one or the other: hard start = time in HR zone, and steady vo2max power = time in vo2max zone?

Yeah I think this is the relevant point. Dr. Seiler always talked about time at/above 90% max HR was important and the basis for training max aerobic capacity.

If I sit in a really hot sauna and crank up my heart rate to close to max, is that just as effective as actually exercising?

If I do really short spurts at 120% of FTP, is that as effective as holding on to that power for multiple minutes?

How do I get to VO2max without requiring my legs to produce a lot of power? (Pedal really, really fast, maybe?)

If I take beta blockers while training such that my heart rate is abnormally low, does that mean that my VO2max won’t increase?

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Cycling is first and foremost an aerobic activity (even short sprints). VO2max is your aerobic capacity. HR is a general proxy for VO2max levels. Training VO2max via HR zones trains your heart to pump more blood to your muscles and trains your muscles to extract more oxygen from the blood.

If your train via power targets you may or may not be hitting the necessary physiological targets (although 120% is good for training power).

Lot’s of variables are involved in VO2max training.

A good primer:


So many question and so few answers.

Give all those scenarios a try and report back. :+1:t6:

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I reckon it depends on what your limiter is. The data seems to suggest you have power left in your legs, but your cardio-vascular system is running full tilt.

What has helped me was lower my cadence. I felt that even though I had power left in my legs, my cadence was so high (105–120 rpm) that it left me panting and I was unable to complete some VO2max workouts. Since lowering my cadence, I haven’t failed one yet, and I feel it has helped me manage 1–3 % more power without failing.

We should all probably listen to both the latest AACC and Empirical Cycling podcasts.

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So to paraphrase the article: it’s a bit of both HR and power and is dependent on the athlete whether they have more to gain from stroke volume or peripheral factors.

Which to me implies a varied diet of interval intensities and structures + long and low.

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This is interesting. I’m currently struggling where I’m doing vo2 at 100rpm plus. Might give a lower cadence a go but fear the cadance spiral of death

Has it ever occurred to you that my questions are simply rhetorical?

Here is some more food for thought.

I got a really good one cooking up right now.


Even more food for thought: if I train at a really high HR during arm cranking, will my VO2max increase less, more, or the same as if I trained at the same HR using my legs?

I’m looking forward to the next episode already.

IMHO it is definitely worth a try. It seemed to have helped me over a hump, but YMMV :slight_smile:

We need both, but I think the biggie is stroke volume.

In developing stroke volume (i.e. changes to the heart structure), yes, I believe both are required for max adaptations. Cycling has perhaps the broadest mix of different types of efforts which is perhaps why pro riders often dominate the VO2max record books.

The article you posted is mostly right and a little wrong. Muscle fibers are mixed so building capillaries around slow twitch fibers builds them around adjacent fast twitch fibers. Usual blah blah on lactate.

This isn’t a complicated thing. Most people who have done high quality training for a few months to a year need to only be concerned about central factors for vo2max improvements. Peripheral stuff gets taken care of through years of normal training, and will help improve stroke volume as well.