If the frigid temperatures have you rethinking exercising outdoors, some doctors and gym owners say the cold may not be bad for your health as long as you don't have a pre-existing condition.

The very cold weather on Tuesday had a class at Chattanooga Functional Fitness staying inside, but co-owner Chase Whited says this isn't always the case during the winter.

"I'll give them the choice. If you want to run outside, go ahead," Whited says. "But if you want to stay inside and do your cardio portion of the workout on the rower, I'm perfectly happy with that."

The gym is heated this time of year, and Whited says he doesn't mind making adjustments if it keeps his clients happy.

"Our mission is just to live a healthier lifestyle," Whited adds. "It's not to learn how to run better in the cold."

If this is your mission, however, Dr. Eugene Ryan at Parkridge Medical Center says be sure to dress in layers.

"Your base layer, then lightweight, heavyweight and big heavy jacket," Dr. Ryan explains. "Because as you exercise you'll be generating more heat, and you'll be peeling off the layers."

Wear a hat which you can pull over your ears. Wear a scarf pulled over your mouth to protect your face and keep you from inhaling the cold air. Also, wear fabrics like nylon, spandex and gore-tex, which pull moisture and sweat away from your body.

Don't forget to drink plenty of water, even if you don't feel thirsty or you haven't broken a sweat. Dr. Ryan also says to be careful when you finish your workout.

"Once you do stop running, you will have to put your clothes back on to make sure you're not going to get chilled quickly," Dr. Ryan adds.

Know your limitations and watch for the following signs of hypothermia, which Dr. Ryan calls the "umbles":

  • "Grumbles," which means you're not having fun and the cold is starting to hurt too much
  •  "Fumbles," meaning you're hands are feeling numb and you have trouble grabbing your phone or keys
  • "Stumbles," meaning you start tripping over your feet
  • "Tumbles," meaning you fall

If you experience any of these, go inside somewhere to get warm.

As long as you prepare, Dr. Ryan says don't stop exercising outdoors or indoors  just because it's winter. Your body will burn a few extra calories.

"If you do the same one mile run in the summer you won't burn as many calories as the one mile run in winter, just because you're trying to stay warm," Dr. Ryan says.