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Heat... heat rate(7 posts)

Heat... heat rateshirt
Jun 3, 2003 12:07 PM
I know we covered this last year a little bit, but I'm so stunned by what the heat is doing to my HR I wanted to see if anybody finds this alarming or not.

Here in "upstate" California, we have two temperatures: 51 and 102 F. Yesterday the switch was thrown to "Summer++" and I went out for an easy two hour ride. Spinning along on the flats in a pretty easy gear, I look down and see 165 on my monitor. From the perceived effort and historical data, I should have been in the high 140s. I mean, I was LOAFING. This was the case through my entire ride, and even during the one long climb, I kept it easy but my monitor was convinced my HR was 185.

The only difference: extreme heat.

I seem to recall us all agreeing that 5-10 bmp was understandable for this kind of heat, but 20??? Oh, I was rested and recovered, too. And today I feel Just Fine.

shoulda been "heart" rate. It's the heat, dontchaknow.shirt
Jun 3, 2003 1:41 PM
Cardiac drift?noveread
Jun 3, 2003 1:51 PM
I am sure those smarter than me will expound on this, but could it have been cardiac drift? Usually caused by dehydration. Could that have been a factor with the dramatic shift in temps you experienced?

Don't think soshirt
Jun 3, 2003 3:27 PM
Cardiac drift refers to the phenomenon of sliding along at a particular HR for an hour or two, then it just starts to move up.

What I saw was consistently high HR from warm up to warm down. I started well hydrated and drank 48 oz. of Cytomax during the workout.
re: Heat... heat rateSharkman
Jun 3, 2003 9:14 PM
Doesn't sound like the heat was solely responsible to me. We have the same heat wave going up here in Portland, and my hr was in line with what I would expect to see, given the intensity.

Could it just be overtraining?

re: Heat... heat rateJon Billheimer
Jun 4, 2003 8:53 AM
Studies on heart rate variability have shown normal variability up to 20 bpm due to heat, barometric pressure, diet, state of training, etc. This is exclusive of dehydration. So what you experienced was at the high end of the normal range, undoubtedly due to the huge temp. variation to which you haven't had time to adapt.

Under similar circumstances two weeks ago I ran an av. HR on a ride about 10 to 12 bpm higher than normal.
Thanks, that's what I was hoping it was. (nm)shirt
Jun 4, 2003 4:23 PM