No matter what your workout goals are, you probably want to maximize the efficiency of your workout, particularly by increasing the calories you burn. Turning up the heat by wearing sweat pants can help you burn a few extra calories, but the difference is a negligible one. Depending on the sport you do, however, there may be other benefits to wearing sweatpants.
Sweatpants increase body heat, causing you to become hot and sweat more quickly during your routine. It takes extra calories to cool your body down when you sweat, so the additional heat caused by sweatpants can help you burn a few additional calories. The additional caloric expenditure is a small one, though, so you won't see much difference in your results simply because you wear sweatpants.
Wicking Away Moisture
Even if you wear sweatpants to stay warm, you'll probably start sweating at some point during your routine. No one wants to walk around with sweaty legs, and sweatpants can help wick away moisture, keeping you cool and dry. Choose sweatpants made of material specifically designed to wick away moisture and steer clear of heavy fabrics that absorb moisture, such as fleece.
Protecting Your Skin
When you exercise outside, you probably notice only the sun that hits your face and your chest. But your legs are just as vulnerable to sunburn as any other part of your body, and sweatpants can help you avoid a sunburn. They'll also save you time if you don't want to worry about sunscreen. In muggy weather when mosquitoes are out in full force, the pants will protect your legs from nasty bites, and if you exercise in natural settings or high grass, your pants will provide you some protection from ticks, spiders and thorny bushes.
Keeping You Warm
Sweatpants are designed to help keep you warm when the temperature is less than ideal. But the warmth isn't reserved only for your skin. Sweatpants trap heat close to your body and can help you warm up your muscles more quickly. It's much safer to exercise warm muscles than cold ones. Theoretically, then, sweatpants might help you reduce your risk of injury, particularly if you tend to avoid warm-up routines.