Does a workout that left you drenched automatically mean you burned more calories? What about the people at the gym that look like they’ve never broken a sweat in their lives? There’s often a misconception that the more you sweat, the more calories you burn, which is not always the truth.
Think of your sweat reflex as your own personal air conditioning system. When you body heats up, your body sweats to allow moisture to evaporate off the skin, cooling it down. How much you sweat (also known as your sweat rate) is an individual phenomenon determined by multiple factors including personal fitness level, body weight, the temperature/humidity of you environment and, of course, how much effort you’re putting in.
If you attend a hot yoga class, or go for a run on a sunny summer day, you’re likely to sweat a lot. You may even notice a significant difference in weight when you step on the scale. However, this weight loss is water weight and should be regained through hydration, not a signifier of how many calories have been burned. The same yoga class in a regular temperature room or on a cooler day likely burns the equivalent number of calories without the same amount of sweat.
The moral of the story? Don’t wear a garbage bag as an attempt to sweat off weight, it won’t do anything except increase you risk of dehydration. And if you sweat a lot, seemingly even when you aren’t putting forth a huge effort, it may actually be a sign of fitness. Fit people tend to have a more sensitive thermoregulation system because their personal air conditioner, so to speak, is accustomed to being turned on.