Originally Posted by
PeteHski
It was the part about not being able to get above 145 on a hard, long climb that made me wonder.
I know we are all different, but I find my HR is quite dynamic in response to really hard efforts. For example yesterday I did a long simulated climb on my trainer, which had a steady 5-6% slope for the first 8 km and then kicked up to an average 10% over the last km, with a few ramps over 15%. I took it fairly steady on the shallow part and my HR stabilised at around 150 (all day level for me). But then I went full gas up the last km and went over the top at 190 (very close to max). My average HR for the last couple of mins was 184. So ignoring the absolute numbers, which I know vary widely across individuals, my delta was still around 40 bpm between comfortable Z2 and a sustained effort well above FTP. When I recovered over the top of the climb my HR quickly dropped back into Z2 as I was still reasonably fresh.
I don’t know much about you diesels to know what is a “normal” HR response to a sudden major effort. For me HR ramps up fairly quickly at VO2 max power level to within 5-10 beats of my max and after 5 mins I an bouncing off my limiter!
I can only say what my data says.
I did a 20 minute Sweetspot at 250 watts with average HR of 126bpm and within a minute of concluding the interval, my HR was down to 100-104. I did just under 6 minutes at 381 watts with HR hitting 163 and within a minute it was under 120 bpm and under 2 minutes under 100 bpm. I've hit 169 bpm this year although no idea when.
When I do shorter intervals with repeats, it might take 2 minutes for HR to come down. Say 350- 400 watts for 3 minutes. But my HR usually doesn't top 160 bpm on those sessions. To get max HR, I need a longer ramp up before going full gas. I am not hitting max HR in 5 minutes like you. On a cardiac stress test, I am still in zone 2 at 10 minutes. I can hit 183 running and last year 175 on the bike, I only test max HR once per year usually in the Fall. I hope post Covid I can still crack 175 bpm. It is a 5 minute tempo into a 5+ minute climb and full gas at the end. I never finish the climb, maybe just under 10 minutes but never timed, just a guess.
One of the inputs to HR control is CO2 level. I do not consider my low HR at harder efforts to be a problem, merely that my legs simply cannot use more. (post covid, my fractional utilization is much lower than in the past and my HR at threshold is also lower by around 10 beats and at least 30 watts)