I’ve been wondering if there’s any good data / information around about how much heat you generate, and how this depends upon perceived effort vs actual watts of output. For example - if 2 riders of same height / weight, similar clothing go out and do the same ride together, one might end up super sweaty & hot, whilst the other might be freezing cold. In this case both will be generating similar amounts of power, but it would seem that they are generating different amounts of heat.
If this is actually the case, then it implies that one rider is more efficient - as heat is a waste byproduct. And… does this relate to your FTP (and what % of FTP you’re riding at). You see this with many other energy systems - as utilisation increases towards capacity the overall efficiency of a system declines. So does the same thing happen with human bodies?
My interest in this was sparked whilst riding with my family and some friends. We’re not the same height / weight etc, but in my case I was riding at an RPE of 1-2, whilst they were riding 7-8. I ended up taking all of their outer layers / additional jumpers / gloves / etc just trying to keep warm, whilst they were shedding clothes as fast as they could. But we were all doing roughly the same power output.
I do significantly more training than my co-riders, and obviously have a higher FTP. But what I’m wondering is - does this impact the bodies overall thermal efficiency at the same power output?
And secondly… does your body actually get more efficient thermally overall? By this I mean - does the % of power that ends up as heat vs “productive power” change in response to physiological training adaptation? I’m not thinking about losing weight - which I expect should impact this (as you’ll shed heat faster), but actual changes in either the ATP or aerobic energy systems.
Or is this a fixed % that depends on your specific genetic makeup / body type / etc?
Cheers! and happy Friday!