heart rate when riding in hot weather?

[azfiddle]

I try to avoid riding in really hot weather for fun... but since I've been trying to stay committed to commuting once or twice a week, I end up riding home when it is in the high 90's or even 100 sometimes. It's about 10 miles, but I usually stop halfway and refill my water bottle with ice at a convenience store.

The last few weeks I've noticed that on those occasional hot commutes home, my heart rate seems to be higher than I expect based on my effort otherwise. On a similar ride in the morning, my heart rate might be in the 130's or 140's, but according to my HRM, it has been up in the 150's.

Any one else notice this?

[Velocivixen]

Heart probably pumping more blood to cool your body.

[luv2climb]

Yes. On Sunday's sufferfest climbing ride I had a 10 mile climb back to my truck with the sun beating down on me. I noticed my heart rate was higher than normal for the level of effort I was putting out.

[Aggie_Ama]

Yes, my heart rate is usually up to 10 bpm faster than what I would expect for the effort. I haven't been wearing my chest strap in the summer because I prefer to ride completely on perceived effort when it is so hot, I find it helps me regulate better. I have to keep myself from doing too intense of efforts in the heat, last summer I threw up 3 different rides from overheating. Once this year I got to the point of dry heaves. It just isn't worth it and it takes usually 24-48 hours to recover if I overheat that bad, I am weak and feel awful.

[Dogmama]

Same here. It's about staying cool. I'll be 10-15 beats over my usual also, even on morning rides when it's only 80 degrees.

[OakLeaf]

Yep. I just read that for every 1°C increase in core temperature, your HR goes up 30 BPM.

Doing intervals on a hot day, I have to walk SLOWLY to bring my HR down to the target range between repeats, and even then it might not go below 150.


Which reminds me ... I need to get off the freakin' computer and go do some speedwork before it gets too hot.

[azfiddle]

Thanks for the input- I'm glad to know I wasn't just imagining it!