aqua-jogging 1:15:30 [2]
Aqua-jogged at the Y with my mom. I had a real belt this time, and it's better than the pull-buoy. I need one slightly less floaty, though. We were checking our pulses, and mine stayed between 115 and 120. I don't think that's very high, but I never find my heart-rate when I'm running, so I don't know. (It was easier for me to talk than it normally is during running, but I don't know if it was because I was bouncing less or breathing easier, or both.) I do know that in Biology class it stayed between 45 and 60, though. If I were running right now (I wish I were), I'd wear my dad's HR monitor.
It's really interesting now to think about my HR because yesterday I was at the WashU med school and we were looking at different people's hearts. Some had had high blood pressure and the muscle was so thick that there wasn't room for very much blood in the left ventricle--that makes me not want to eat lots of salt. But we also learned that it decreases your blood pressure to exercise because of the new capillaries, so I think I'm okay. I also got to see an artificial pace-maker. I wonder how it gets turned up when they exercise, but I didn't get to ask. I did ask what limits a person's maximum HR, though. It's because if it went any faster, the blood wouldn't have any time to fill the chambers and it would be beating faster for nothing. That explains why your maximum heart rate gets less as you get older. Except that the 220-your age makes it seem like your heart grows at a constant rate, which seems kind of weird to me; if I lived to 100, would it explode?
Wow, this is a long entry. I should be doing my Physics right now. Unless I count this as studying for my test on the circulatory sysem...I'm going to go read about artificial pace-makers.