Originally Posted by
DaveWC
Q: "Is how much a person sweats during a workout a good indicator as to how hard a person works?" – RI Jones
A: Great question RI! Since our workouts are often sweat filled sessions, we were anxious to know the answer to this one too. We asked Michele Olson, Ph.D., professor of exercise science at Auburn University in Alabama to tackle this question. This was her response:
"The reason we sweat is to control our body's temperature. When liquid hits our skin (from the inside) and then evaporates, the evaporation is cooling. However, this is not the most accurate indicator of how intensely you are working out or how many calories you are expending. In fact, you actually burn more calories running outdoors in the cold versus summer in the heat."
"How? To warm our bodies, our muscles will perform extra small and rapid contractions that are usually not felt, but anytime your muscles contract more, they use extra calories. Heat is released every time a calorie is burned — and this is what helps keep the body's core temperature up and stable. Sometimes the twitching is very noticeable and we call it shivering. But, the process of sweating does not require active calorie burning. So, don't rely on sweat as a sole gauge of exercise intensity. A combination of heart rate and perceived effort are much better indicators of how hard you are working and how much energy you are expending."
Thanks for the reference Dave. Hey, maybe I am wrong about this...but relating sweat to exertion is ridiculous. A rider who rides at 0 deg F may have 1.5 x's the exertion of riding at 85 deg F and sweat three times as much at 85 deg. I am on board with relating amount of calories burned relative to level of exertion. What I am less sure about is...for the same level of exertion at higher temp, to me, I drop more weight. The best times at the Boston Marathon are always in cooler temperature. This isn't related to exertion. Exertion is the same among elite runners. Their times are faster, likely because of delta T aka the difference in ambient temp versus their body temp. I have to believe more calories are being burned at the same level of exertion in higher temp and hence more weight loss.