Heart rate is a very good guide to how hard someone is trying.

http://www.toppfysik.nu/...ing-competitions.pdf

"We conclude that during competitions of <120 minutes heart rate is a valid and reliable predictor of exercise intensity and energy expenditure. For competitions of <240 minutes heart rate will increase by <5 beats/min relative to workload and therefore over predict exercise workload and energy expenditure."

If you are holding 300 watts, your maximum heart rate is 180 bpm and your heart rate is at 95% (171 bpm) you are trying bloody hard.

If heart rate wasn't useful why do you think so many scientific studies look at it?


If you and your "when you know your power, then at best heart rate is irrelevant but at worst misleading" fundamentalist extremists don't use heart rate fine, but why do you get so annoyed by people who do use it? Some of you have become a sort of Taliban who wish to impose your extreme fundamentalist views on everyone else.


Methinks the reason is looking at heart rate alongside power exposes the flaws in the power only approach. For starters heart rate alongside power exposes how TSS is flawed.