HR cap and stroke volume

Physiology
1

@steveneal Do you know this one? (or whoever knows)

Does a heart rate cap of zone 2 or 3 (out of 5) effect stroke volume, during aerobic training?

I ask because:

  • i’ve been training with a HR zone 3 cap lately instead of the HR zone 2 cap i used last year
  • the reason is that i trained on track and can’t keep HR in zone 2 in the corners
  • I wanted to train on the track to improve the strength I need for the corners
  • now when i do my ‘zone 2 training outside of the track’ i have better power output than last year but 10 beats higher HR, while RPE is equal to last year.

Is my stroke volume reduced due to the zone 3 training?
Did i become a CHO junky?

2

Interesting question.

I use heart rate ceilings often because it helps two things.

  1. my zone 2 ceiling would be at LT1 - so the athlete could ride by power at or below LT1 but not go over the HR ceiling

  2. my zone 3 ceiling would be Lactate Balance Point (in my terms) but it is equal to fat carb crossover in a metabolic cart test.

so with regards to my zones, I am trying to keep people in an energy distibution zone, not really thinking of stroke volume or not. However, I guess when you are training this way, there ends up being a lot of endurance training without increasing lactate or CHO usage increasing (same thing) during the longer sessions.

The other reason for my heart rate ceiling, is that it is also related to the respiration system. Part of the cardiac drift puzzle is our respiration system fatiguing, which you can only measure with a met cart, or by doing forced vital capacity tests (FVC and FEV1 tests) through a ride.

I am not a track racer or even rider, but the banks producing more power is similar to sections on a mountain bike, and I think that speed maintenance is an important part of our sports so the training must be incorporated.

If your zone 3 heart rate (however you define it) is above your fat carb crossover point, you are then training a very different energy system.

Here is an example of two very similar athletes, but if you look at their LBP they are very different, to me this is how I individualize zone 3.

It is also how creating a zone above the first deflection can cause problems in zoning.

They are identical at LT1 and LT2, but LBP is very different.

athlete compare lt 1 2 and LBP
athlete compare lt 1 2 and LBP746×806 88.4 KB

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3

Thanks @steveneal . You triggered me there as I have not measured my zones. I still go by Karvonen based on true HRmax and HRrest.

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4

@stevenea am I right to presume that your tempo workout with the HR cap is targeting just below/at the LBP (fat carb crossover point?

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