Heart. Rate question

[Lmasursky]

Hi,

I have a question about heart rate zones for lack of a better term.

Coach Conor often refers to “max” or “max heart rate” with percentages.

I think he means “heart rate at VO2Max.”

This is confusing for me because my actual max heart rate, on my current fitness, is much higher than my heart rate at VO2Max.

That is, in a given hard session I will see a BPM that isn’t really “reachable” much less sustainable.

Thing is, my heart rate at what I’m fairly confident is VO2Max (sustainable for a VO2Max related time (like max of five minutes to body shut down) is like 5 beats below that top end.

I mean I can ride myself to that VO2Max level, keep that level, and VO2Max power for, at the most like 5 minutes, and never see that “actual Max.”

In other words it tops out at the VO2Max rate when I’m doing VO2Max efforts.

If I do stacked anaerobic intervals, I will see that high rate, and these are efforts that cannot go beyond 90 seconds to body shut down.

What happens is, on those anaerobic ones, say 1 on 1 off for 10 reps, the rate is actually lower than VO2Max, but it will jump up on a couple reps, where on VO2Max it finds a steady point as long as I keep the power steady.

For context I will do 4x4 VO2Max workouts (2 min. rest) sometimes, this is when I will see that “steady max” level.

One of my questions is which number do I use for “the max” when calculating a “percent of max” level or number?

I ask because the two numbers give quite different ranges in terms of PRE, repeatability, and to some extent gains I have seen.

As a preview, I think the better number is the lower one. Do you agree?

Am I alone in this, or do people have this same spread of high heart rate numbers?

Thanks,

Leo
Tucson

[Boulderjoe]

I recall hearing Dr Seiler say on the podcast (a paraphrase is the best i can do)… “max heart rate is the highest heart rate you actually see on your monitor when exercising”. Is that the correct rate to use?

[ryan]

Hi @Lmasursky, and welcome to the forum! Great questions. This can be a tricky one to figure out, but as @Boulderjoe suggested, Dr. Seiler has some great workshops to address this, particularly the one on How to Find Your Maximal Heart Rate.

I’ll suggest that Dr. Seiler’s slide showing that HR at VO2 max may not always occur together is a great one to review. I have done a lot of VO2 max tests in the past and have witness this many times. In addition to that, fatigue is another major consideration. You might have an absolutely banner performance in a workout or race and see what you might consider your actual “maximum” HR. That’s great. It means you were well-rested, motivated, and all the other things that need to line up to allow for peak performance.

The thing is, that’s not your everyday performance. So day to day, you’ll see something close to that if you’re rested, but likely won’t hit that every single time you go at a maximal effort. For setting ranges and talking about % of maximum, I use the high number because I know it’s there and I can hit it or get close most of the time. We of course need to take into consideration age-related declines in maximum HR, but that’s where testing regularly would help out.

If you’re not rested and are carrying some level of fatigue day to day, it will be even harder to reach that maximum, and you might experience the inability to hit whatever target HR or target range you have planned for that session. That’s a great indicator that you need to recover. I’ve been guilty of this myself where I ride a little too much in that grey zone. I might get fit with some decent endurance and my repeatability at threshold, but when it’s time to go hard, it’s just not there.

Here are some examples showing different workouts where maximum HR was pretty close, and essentially confirmed that my setting of 181 is fine to continue using.

1. Hard interval workout where I was doing hot laps with maximal climbing efforts. HR hit 180 beats (my highest maximum I’ve seen in 2020 is 181)
   

   

2. Short Track MTB Race where HR maxed out at 179 (98% HR max)
   

   

3. By contrast, here’s the 4x4 workout from yesterday. This is more what I would consider that “steady max” level you suggested. 166 was the average and 176 was the max HR achieved on the last interval.

   

So looking at these 3 sessions, I would still recommend that higher number (for me it would be the 180/181 beats) for max HR in setting percentages off for training. If you find that you’re not able to get anywhere near these, it may be worth considering additional fatigue that may be carried day to day and re-assess the work/rest ratios within the training block. For something like 4x4, you should be hitting at least 85-90% of maximum HR. Otherwise, I would suspect that the body is not recovered, or there was an error in the selection of the current max HR. See our discussion of this on 4x4 Pacing where Trevor shows an example of not being ready for that type of interval session.

I hope that helps!
Coach Ryan