If it feels like winter will never end, look on the bright side: The cold air and snowy streets are giving you a workout and you don't even know it.
So relish the remaining weeks -- consider them boot camp for spring -- and check out these five ways winter makes you fitter:
It Boosts Your Metabolism
As your body shivers to keep warm, it converts calorie-storing white fat into calorie-burning brown fat, according to a new study published in the journal Cell Metabolism. It turns out all that tooth-chattering releases the hormone irisin -- the same hormone released during a workout. Thanks to irisin, your cells release more heat, helping your body maintain its internal temperature, according to study author and National Institutes of Health researcher Dr. Francesco S. Celi. "Perhaps lowering the thermostat during the winter months could help both the budget and metabolism," Celi said in a statement.
It Challenges Your Muscles
All that shoveling and plodding through snow is a real workout for your muscles, which have to work even harder in the cold. The low temperatures also dampen your flexibility, so stay stretched and your muscles will be supple for spring.It Makes You Sleep More
The longer nights of winter lengthen your body's melatonin signal -- the molecular cue for bedtime. This can help you fall asleep and stay asleep. Take advantage of the natural sleep aid to get a good night's rest, but don't overdo it: Sleeping too much has been linked to obesity, diabetes and heart disease.
It Helps You Hydrate
Winter is primetime for soups and teas -- tasty ways to get your water. Broth-based soups packed with veggies make a healthy meal, but beware the sodium content. Some store-bought soups use salt as a flavor boost. When it comes to tea, try something minty. Peppermint green tea is a refreshing way to warm up without the dehydrating effect of caffeine.It Motivates You
Remember those New Year's resolutions? You've had January to think about them, and now it's time to act. Whether you want to lose weight, gain muscle, quit smoking or eat healthier, winter is a great season to hunker down and get it done. Just think how great you'll feel when spring arrives.Take Care in the Cold
While winter can help you get fit, make sure you do it safely. Low temperatures raise the risk of hypothermia and frostbite, and heart-related deaths are more common in the colder months. So bundle up if you're going outside and don't overexert yourself.