PT on the Net Research

Calories Burned in Heat vs. Cold


Question:

Given the same intensity and time exercised, is there any difference in the amount of calories being burned if I were to run in cold weather or in humid conditions?

Answer:

Below please find two brief research results that correlate to your question: In ACSM's Guidelines for Exercising Testing and Prescription 6th edition, in the section about metabolic equations to calculate energy expenditure: it states: "...although the accuracy of these equations is unaffected by most environmental influences (heat and cold)..."

Do I burn off more calories exercising in the cold?

Cold weather itself does not increase calorie needs. (And remember, the weather can actually be tropical inside your ski outfit or running suit!). However, your body does use a considerable amount of energy to warm and humidify the air you breathe when you exercise in the cold. For example, if you were to burn 600 calories while cross-country skiing for an hour in zero degree weather, you may use an estimated 23 percent of those calories to warm the inspired air. But you use the heat you generate with exercise to warm the air you breathe and prevent your lungs from getting chilled. Hence, you might not sweat as much. But, you don't burn extra calories, unless your body temperature drops and you start to shiver. In the summer, you would have dissipated this heat via sweat.

You may, however, burn off a few more calories to carry extra clothing. Athletes who lug around heavy clothing and sports equipment (i.e., skis and ski boots, heavy parkas, snow shoes) do burn more calories. For example, the Army allows 10 percent more calories for the heavily clad troops who exercise in the cold. But winter runners or race walkers generally wear minimal heavy clothing...

If you are too scantily clad (or have little body fat) and your body becomes chilled, you will need more calories to stay warm. For example, scantily clad research subjects who exercised in the cold (14 degrees F) burned 13 percent more calories than when they performed the same exercise at room temperature - about 450 versus 400 calories per hour.