DR. MITCH: Do You Really Burn More Calories Exercising Outdoors When It's Cold?

If only that were true! Unfortunately, even though it seems intuitively obvious that you should burn off more calories by exercising in the cold, the reality is a lot more nuanced.

Your body wants to stay at a specific temperature. That set point,  98.6 F or 37.5 C for most people, is the temperature that most of the chemical processes that keep us alive work best at. Raise our temperature too high, or drop it too low, and things start to deteriorate. This is why our body has all sorts of ways to keep itself at the right temperature. In the cold we shiver and turn on brown fat. Brown fat keeps you warm by burning calories to generate heat. (As opposed to white fat, which is mainly just a storage depot for excess calories.)  Awesome, you think. If I exercise in the cold, not only am I burning calories to exercise but I am using up extra calories to stay warm. Unfortunately for those of us trying to lose weight this way, this is where the science is more complicated. Exercise itself generates heat. So shivering doesn't kick in nor is brown fat turned on and so you don't get those extra calories being burned. Sorry!

On the other hand, while I strongly encourage people to exercise, remember that if you want to lose calories, exercise, while important, isn't enough. Calorie reduction is a larger contributor to any weight loss program. So do exercise but watch what you're eating if you really want to lose weight.