Training & Nutrition - Unsophisticated HR Question

I'm finding in these cooler winter temperatures (50 degF or so) that I can sustain high 140's fairly comfortably (I'm mid-60's) when climbing. As the temperature warms I'm more like a low 140's guy. It make's sense that this is simply the effect of having to cool my 200 lbs. Just looking to see if this is consistent with others' experience.

I've not seen over 158 in the last three years of cycling, have never done a max HR test and don't feel the need. My wife and I are recreational tandem riders, mostly 100K and 100mi organized rides. FWIW my resting HR is mid 40's.

I'm age and size similar to you and my experience with HR is pretty similar. Heat probably affects me a bit more than you and my resting HR is much higher than the 40s, I think anyway. About 162 seems to be my maxHR. Note that going uphill we are slower and the heat exchange from air passing over the skin will be reduced.

I'm the opposite. My HR is always higher for the same power efforts if I'm hot. That can be either on a warm day or inside on a trainer with inadequate ventilation.

I'm the opposite. My HR is always higher for the same power efforts if I'm hot. That can be either on a warm day or inside on a trainer with inadequate ventilation.

Greg, my description of the situation(s) was probably confusing. A better way to describe my my HR behavior on hot climbs is by the time I'm in the high 140's the increases in HR are an attempt to cool my body. I probably cross over from useful power to cooling mode just over 140 depending on how hot it is.

I dunno. I have the same reaction to heat as Greg. If you're saying that your HR does go up, and that seems to limit your power, that's consistent with dehydration. If you're saying that your HR does not go up no matter how much you punch the pedals, that's consistent with lack of nutrition, which happens more frequently in the heat because, even though you're eating, your stomach isn't emptying. Fix for that is Endurolytes and more water.