Originally Posted by
CyclingBK
Good to hear. It’s fascinating to consider the reason for the prolonged yet “normal” elevation. Not from the standpoint of “why”, as you said, you ran up your hr to relatively close to capacity trying to keep pace for a long time.
But what is the heart doing in its elevated state all that time after the workout? Is it recovering itself? Is it that at a cellular level, the mitochondria (lol) are so depleted that the heart is working overtime to get them replenished?
You should “annoy” her and ask her, she may just want to show off her knowledge. And I’d be curious as well ; )
It's simple. Dehydration means a decrease in blood volume. Nevertheless, the same amount of blood has to reach all your tissues, so your heart has to pump harder to move the smaller amount. Imagine a circular hose with a pump. You're measuring the volume of water which passes a particular point. If the hose is smaller (lower blood volume), the blood has to move faster to move the same volume past your measuring point. Thus the pump runs faster. The "athletes heart" has larger chambers, thus more capacity, thus is not bothered as much by dehydration.
I once did a 105° 3000' pass climb (third pass of the day). I became severely dehydrated. Luckily I had a known source of water and a bit of shade. My normal resting heart rate was 46. Sitting in the shade, I was at a steady 125. I sat in the shade and drank water until it dropped below 100, then continued on up. I made it fine, but that was a hard climb, luckily the last long pass climb of the day. If it'd been life-threatening (no shade, no water) I could have hitched a ride.