I can't rise my HR above 92%HRm

Hi, recently I’ve started more training on a road bike with HR and power meter.
But I have always a problem to reach high HR, maximum i reach on a bike (road or mtb) is about 91-92%HRm.
You may ask how i know my max, I reached it on few occasions while running or on my road bike - but on a trainer (204bpm).
(FTP 273W - 3.8W/kg - from 20 mins test)
Outside I can reach >90%HRm in 2 mins, but it has to be near-maximum effort - 158%FTP avg from these 2mins (it’s my current 2mins max. -431W)
or I can reach >90 on longer sustained effort, like 10 mins in Threshold power.

Last month I was doing VO2max intervals (in PZ5 - 105-120%FTP), but now I realised that maybe I wasn’t pushing myself hard enough,
coz I wasn’t reaching >90%HRm. I can ‘easily’ reach 85%, but later it starts to be real difficult, I mean, my legs will die first.
Is it normal? (I know that everyone is a bit different)
Or should I try a bit harder? (next time I’ll try hard-start intervals, to be closer to 90%, maybe at the expense of overall duration).
but definitely, more than 92%HRm just doesn’t look like possible.
ah, another thing, I ride flats now :slight_smile: (it could affect things a bit? but my HRm on a trainer I did on flats too, but final sprint had candence probably way above 100rpm, but i don’t have any data from it)
my cadence above 105%FTP is 90-100rpm.

Its possible to have different definitions of HR_max depending on the test conditions/sport.

If I specifically go out and hammer my local hill, which is a 4 minute vertical climb of 100m at 10%, I can get an artificially high heart rate, that I would not normally see. Doing this hill, I have seen 192bpm, when I would say that my max heart rate is 182bpm.

Since getting a power meter, I see my heart rate depends on how long I have been riding, as well as the intensity. This drift higher with time is particularly noticeable if I do a turbo session, with intervals which are at the same power level. Over a turbo session, the heart rate increases for a given power level.

Basically, heart rate is a function of lots of variables, the majority of its variance is explained by intensity, but once you really start looking at it, you need to include time/caffeine/training history etc.

ok, but then, how can you say that VO2Max zone is >90%HRm ? is It >172 or >163bpm for you ? or you just prefer to use 105-120%FTP ?

during my VO2max training I can accumulate about 15-16 mins (in 3min intervals), before it starts to be impossible to keep >105%FTP, but then, maybe my predispositions or current fit is off a bit, as before I was just doing enduro/dh riding, without proper training.
(max power could be probably a bit better, as I still ride on flats. after 2mins there is a plateau, because I’ve never tried 5-10mins max efforts)

Bingo, I dont bother with heart rate any more. I literally dont bother putting my heart rate belt on, as its a faff and interferes with my zips on my tops, and I dont get any value from it, over and above power.

Once you start mapping the relationship between heart rate and power, you will see that heart rate could be anywhere in a 10% range for a given power, or for a given power, heart rate may vary as much as 10bpm (maybe more, I’ve not quantified it precisely).

The key takeaway for me, is that heart rate is inferior to power for training.

I was fortunate to have a discussion with someone doing pretty well at triathlon a couple of years back, and she said her improvements were mainly down to:

  • getting a coach
  • training with power
  • watching her diet

I figure that in the absence of a coach, Trainerroad will suffice (maybe its better, controversial). The powermeter was initially from a Kurt, but now I have seen the benefits, I’ve ponied up for power cranks.

Speaking only for myself and not as a medical professional, my experience is that my max heart rate running is way higher than cycling of any sort, and mtb is slightly higher than road. Running max is 194, mtb max is maybe 184, road I can occasionally get it to 182.
I just use different max heart rates for the different activities.

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This is potentially down to recruitment of muscle mass. The different sports recruit differing levels of muscle. Then you also have the pain threshold thing, where the body automatically protects the blood supply to the heart and diaphragm by creating pain in your legs. Some people are better than others at pushing on through this, I think. A mate was very good at taking himself deep into anaerobic distress, maybe because of running on the track and doing things like 10x 400m reps. He then got tachicardia.

I believe the recruitment of muscle mass is different. I just use much more of my body running than cycling.
I’m sure there is something to “going deep” meaning different things to different people, in my case I don’t think that explains my heartrate variance by activity.


yep, with running I undestand that. Way more muscles activated - easier to rise HR.
Probably it was similar with my HR max on a trainer - I was able to spin way faster than on a road.
Also Garmin says that my Threshold is at 180bpm (89%HRm), which again, it’s difficult to achieve, on a bike I just use PZ4, and I’m trying to base my pace (if there is a climb I want to conquer :slight_smile: ) on my power output and knowledge about my body.

Haha, cadence is another thing which impacts heart rate. I think its impossible to real nail down the relationships between these things by simply eye balling the data.

Ideally, you would collect all these different features in some kind of json file store, and then at a later stage whack it through a gradient boosting model, which would chuck out some feature importance and tell you which variables were important in determining your heart rate.

My hypothesis, it would not just be power accounting for variability in heart rate, although it may account for 90% of the variable importance.

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