Yesterday’s 3 inch blizzard turned into 7 inches by the time it was done in my Chicago neighborhood. After snow blowing and shoveling multiple times, walking the dogs, walking myself and cleaning off the car, I came indoors ready to eat. I couldn’t stop eating, all throughout the day – my metabolism was revved up, which got me to wondering…”do I burn more calories in the winter?”
Most information says cold weather doesn’t increase normal caloric expenditure by a significant amount. In other words, I don’t burn too many extra calories just because it’s cold out. If I elevate my heart rate and I’m outdoors shoveling, I burn the calories from the work of shoveling.
Any small increase in calories burned outdoors in cold weather may be due to the warming of cold air by the lungs and from the rewarming of skin that has been exposed to the cold. So, my body does burn a small amount of extra calories to keep me warm. If I heat up (get sweaty), then get cold and my body starts to shiver, that’s a different story. When a person is shivering, the body needs to work harder to maintain body temperature. Shivering can burn about 400 calories per hour (depending on how you are dressed, how long your exposed, and the temperature) but it also depletes glycogen stores and leaves you feeling fatigued. (Not a desirable state.)
Now let’s talk walking…
The calories burned during walking depend on speed and terrain. Walking from your car to your workplace in perfect weather conditions and on level ground would burn about 136 calories per hour for a 150-lb. person of average build. Making that same walk uphill in the snow, and the rate can jump to over 400 calories an hour.
According to Bill McArdle, an exercise physiologist and scientific advisor to Weight Watchers International, walking in packed snow increases the calories burned by 60 percent, compared to walking on a paved road. “Why does that happen Bill?” “Walking in soft snow triples the calories burned because the snow provides resistance, compared to walking at the same speed on a treadmill.” Bill also reminds people “an added benefit of using snow as resistance, is the additional toning for large muscle groups in the legs.”
There may be one other reason for burning more calories in a cold climate compared to a warm one. In a hot environment, intense exercise can cause the body’s core temperature to rise to near dangerous levels. This can result in blood being shunted away from the working muscles to the skin, so that heat can be released. Bottom line – you can’t exercise for as long in a hot climate as you can in a cold one.
When I look at all of the time I spent outdoors shoveling, re-shoveling and then shoveling again, I can see that I did more work over a longer period of time… and I was out in the cold. I also walked a mile through almost a foot of un-shoveled snow which definitely provided some resistance to the large muscles in my legs. No wonder I was so hungry, all that extra activity in the snow and cold burned extra calories!