You may have heard that you burn more calories in cold weather than in moderate or hot weather. And in some instances, that's true.
But before you plunge into the nearest snowbank for some no-effort fat-burning, it's important to weigh the advantages and disadvantages of getting cold on purpose.
Under the right conditions, being cold can make your body expend as much as 400 extra calories an hour. But research is still being done about the efficacy of using cold as a fat-burning method.
Heading for a “Brown Out”?
Researchers currently believe that the body's reaction to cold weather helps burn more calories because it affects brown fat. In colder temperatures, brown fat is activated in order to produce heat that your body needs.
The interest in brown fat activation as a potential weight-loss tool comes from the fact that brown fat burns calories in order to produce heat. It may even use other body fat as fuel to burn those calories. Mayo Clinic points out that exercise may also stimulate brown fat to burn calories, which is why exercising in cold weather is a potential one-two punch toward calories.
Feeling Cold vs. Shivering
Brown fat cells don't magically sense when the temperature plunges. It's the act of shivering that produces a hormone known as irisin. Irisin is the same hormone produced by exercise.
Limited studies have indicated that it's the shivering itself that burns calories. Muscles contract and loosen in quick succession to raise the body's core temperature. In doing so, brown fat tissues are activated and the calorie-burning process begins.
Read more: Why Cold Weather Running Is the Best
There’s Cold — and There’s Cold
Winter weather isn't automatically a reason for your body to turn into a calorie-burning machine. That's especially true if you're exercising. In fact, the American Council on Exercise notes that working out, by itself, is usually enough to raise the body's core temperature to a comfortable level in lower temperatures.
If however, you're in extreme conditions and moving around isn't enough to keep you warm, shivering will set in. Shivering for an hour can burn up to 400 calories, notes ACE, often on top of the calories you're expending on your activity. (Theoretically, just staying still in extremely cold conditions would burn 400 calories, although few people would do that voluntarily!)
Calculating Cold Weather Cons
Trying to decide between hitting the gym and braving the elements for your workout? For some people, the pitfalls of winter weather can stop a workout in its tracks.
If you're trying to lose weight, extreme cold can actually impede your progress. One obvious reason is that it's hard to find the motivation to even step outdoors, let alone try to ramp up your metabolism for the day.
When you do go out in low temperatures, not preparing for the conditions can make you too uncomfortable to workout for very long. Of course, it also leaves you vulnerable to chills, frostbite and hypothermia. Make sure to dress in layers — preferably with inner layers that use materials designed to wick moisture away from your skin while guarding you against the elements.
Weighing the Advantages
If the temperatures aren't too extreme, your workout performance may improve, allowing you to burn more calories each time. Without the risk of humidity and high temperatures to worry about, you may feel comfortable enough to do walk, skate or take a run for a longer period of time.
Still need a nudge to head outside for a winter workout? You'll also be getting some much-needed vitamin D, along with boosting your immunity during flu season, points out the American Heart Association.
- National Institutes of Health: "Shivering Triggers Brown Fat to Produce Heat and Burn Calories"
- American Council on Excercise: "Do I Burn More Calories When it is Hot Outside or Cold?"?
- Mayo Clinic: "What is Brown Fat?"
- American Council of Sports Medicine: "Safety Tips for Exercising Outdoors"
- American Heart Association: "Cold Weather Fitness Guide"