Where does the heat come from that your body produces after doing physical activities even in the cold?

Question

Where does the heat come from that your body produces after doing physical activities even in the cold?

In: Biology

Answer 1

Another thing besides the other comments is the inefficiency of metabolic reactions. One molecule of glucose makes about 30 ATP molecules but the energy content of a glucose molecule is about 100 times that of ATP. The remainder is lost as heat during metabolism.