A colleague of mine sent a link where he attempts to prove that (because Dr. Gabe Mirkin said so…) you burn more calories in hot weather than you do in cold. I’m afraid that he is confusing sweating directly with energy burn. Sure, I admit that you can loose weight through sweat, but your body only has soo much water to lose.


In this article, the good doctor states no references and it can be assumed to be a casual observation at best. He notes:

On the other hand, in cold weather, your heart only has to pump blood to your muscles and very little extra blood to your skin to dissipate heat. Your muscles produce so much heat during exercise that your body does not need to produce more heat to keep you warm. So your heart works harder and you burn more calories in hot weather. This information should not discourage you from exercising when it’s cold, because staying in shape is a year-round proposition. However, it may help to explain why so many people find the pounds creeping on in the wintertime, even when they stay active."

Somehow, I doubt he conducted any study on these individuals’ dietary habits throughout the entire year of their workouts. The last line is very telling… Wintertime is often the time of the year in western cultures where people tend to celebrate more and eat more. People rarely increase their workouts just because it’s winter.

Furthermore, I disagree with his statement regarding the heart needing to work harder to cool the body. In a prior statement, he says:

You burn fewer calories when you exercise in cold weather than you do when it’s hot. The hotter it is, the more extra work your heart has to do to prevent you from overheating. More than 70 percent of the energy produced by your muscles during exercise is lost as heat. So the harder you exercise, the hotter your muscles become. In hot weather, not only must your heart pump extra blood to bring oxygen to your muscles, it must also pump hot blood from your heated muscles to your skin where heat can be dissipated.

So, the conclusion to cooling your body should be to stop moving! It seems to me that Dr. Mirkin is suggesting that your heart must work harder to become cooler… The one point I do agree with Gabe on is that your body needs to dissipate heat (aka energy) as the muscles move. His post only seems to discourage working in the cold weather times. What better way to keep the body cool while working out than to be in a cool environment?