The ins and outs of exercising in cold weather

We live in Austin, not Minneapolis, so we can bike, run and, yes, even swim outdoors all year round. But exercising in cold weather requires different considerations than exercising in brutal heat. We've rounded up some odd facts, answered eternal questions and put together helpful tips to help you stay active in this winter. Now grab your gloves and get crackin'!

Can you get dehydrated in the cold?

Dehydration doesn't just occur under a hot summer sun. It's one of the biggest problems when exercising in cold weather. Most people don't feel as thirsty when it's cold, and they drink less. That's because cold actually inhibits the thirst sensation, according to a University of New Hampshire study published in Medicine & Science in Sports & Exercise. Blood moves away from the extremities and into the body's core. Since the fluid level in the central body doesn't drop, the kidneys don't get the signal to conserve fluid. The thirst response decreases by about 40 percent.

What's the best temperature for running?

Austin runners already know it's better to run a marathon in February than August. A study from the U.S. Army Research Institute of Environmental Medicine proves it. After studying years of results and weather data from six major marathons, researchers showed that colder temperatures meant faster times. The ideal long-distance running temperature, according to the study, is 41 degrees. The times of top male runners were 2.5 percent slower than the course record when the temperature was between 51 and 59 degrees. Finishing times were even slower at higher temperatures.

Is it miserable to swim in Barton Springs in the winter?

If you can hack the pool in the summer, you probably can hack it in the winter. That's because the water at the pool is roughly the same temperature year round — usually 70 or 71 degrees. It's getting out that's tough, especially if it's windy. Be sure to have a towel, jacket, socks and hat handy, and change out of your wet swimsuit as soon as you can. A sunny day and a wetsuit help, too.

Can your lungs freeze in extreme cold?

Nope. People in cold climates used to avoid running outside in the winter, but freezing lungs are a myth, according to Blair Gorsuch at the CardioPulmonary Rehabilitation Center at Proctor Hospital in Peoria, Ill. The body naturally warms air before it enters the lungs.

Why does your nose run in the cold?

The nose's job is to warm and humidify air that you breathe into your lungs. If the air is cold and dry, the nose increases fluid production. Sometimes it makes too much, and your nose runs. There's another factor at work, too. Water in warm air condenses in cold air. When you breathe warm air out your nose, some of it might condense at the tip of your nose, where it's cold. Voilà, runny nose. A runny nose also could be a sign of exercise-induced rhinitis. Physical exercise often triggers the symptoms, which include inflamed nasal mucous membranes that pump out more mucus during exertion.

Do you burn more fat exercising in colder weather?

Probably not. A 1991 study published in Sports Medicine found that "the combination of exercise and cold exposure does not ... enhance metabolism of fats." In fact, some bodily processes involved in fat metabolism slow down in cold temperatures. That slowdown might be because blood vessels in peripheral fatty tissues constrict when it's cold outside. The heart rate is usually lower in cold weather exercise, too.

Do exercisers catch fewer colds?

Yes, according to a 2008 study reported in the British Journal of Sports Medicine. After tracking about 1,000 American adults for 12 weeks, researchers determined that regular aerobic exercise might cut the risk of catching a cold or other upper respiratory infection nearly in half. According to the study, people who exercised at least five times a week had up to 46 percent fewer sick days than those who exercised only one day a week or less. The exercisers had an average of 4.41 sick days versus 8.18 days for the couch potatoes. And when they did get sick, their symptoms were milder.

What about goose bumps?