#trailrunning #running friends: What’s going on here then? Two charts, one from the flattish New Forest Marathon and the other from the hilly Clarendon trail marathon yesterday. In both, my heart rate increases a lot after about two hours and stays high. I ran Clarendon with my wife and her HR is usually much higher than mine but not in the second half of the race. I was wasted at the end and she was fresh as a daisy 1/2
Donoban
Dehydration: As you sweat, you lose blood plasma. The heart has to beat faster to keep up. Low energy reserves: After 1.5 to 2 hours of effort, glycogen levels drop, and the body uses less efficient energy sources, so the heart works harder. Heat: Body temperature rises, causing blood vessels to dilate. To maintain blood pressure, the heart rate increases. Physiological stress: Long efforts activate the sympathetic nervous system (adrenaline), which naturally raises heart rate.