Muscles use oxygen, sugars, and fatty acids as fuel. They give off heat to keep you warm, specially when it is sub-zero like last Saturday morning. When you run fast, your muscles give off so much heat that you perspire to COOL you off. How about that?
In cold weather, your muscles “shiver” to generate more heat. As muscles work, they ouse lots of fuel from the blood. Your breathe harder and your heart pumps faster to supply more oxygen and remove the waste. After some time, the blood can’t keep it up. Then, you feel tired and must rest until the fuel is replaced in your muscles and all the waste is carried away.
AMAZING ISN’T IT?
20/20 VISION — SEEING YOUR POSSIBILITIES!