Cold winter mornings may not look so inviting when considering an early run or workout. But if you really think that staying comfortable in your bed ratchets up better health benefits, it’s time to think again. Getting up and working out in the great outdoors (or even just your own backyard) is one of the best ways to optimize your health in winter, and here’s why. 

Is Exercising Outdoors in the Winter Good for You?

1. Your Body Performs Better in Colder Weather

Working out in cooler temperatures requires less cardiovascular effort than training in warmer weather. This is because, in a hotter climate, the heart has to keep pumping blood to the skin to promote sweating. 

While this pulls the breaks on dehydration, it can put a lot of pressure on the heart. In one study carried out by St Mary’s University in London, running in cold conditions created a 6% decrease in athletes' heart rates. The overall benefit? Less cardiovascular stress and better overall performance. 

Related: The Best Gear to Crush Your Winter Workouts

2. You Burn More Calories

Alongside a healthy heart, cold-weather workouts can help you burn more calories. 

Our body stores two types of fat: white fat, which is often hailed as "bad fat" because it accumulates around the organs in the stomach, butt, and thighs, and brown fat, which is viewed as "good fat" because it burns energy to generate heat in our bodies. 

Related: This Lesser Known Fat Will Actually Increase Your Metabolism

Recently, however, researchers have discovered that white fat can be transformed into calorie-burning brown fat through exposure to cooler temperatures. 

The authors of the study, published in the Journal of Clinical Investigation, claim that that brown fat activity “is regulated from the brain, based on the need for heat for body temperature control … and that during prolonged (heat production), the components of ingested food are channeled to the tissue as a continuous supply of substrate.”

In other words, as long as the brain keeps thinking that the body is cold, it’ll push brown fat — along with white fat in a supporting role — to metabolize. So, going outside for a run or a brisk walk (as long as your body doesn’t heat up too much) will activate this fat metabolism and help you burn some extra calories.

3. You'll Boost Your Immune System 

Contrary to popular belief, it's actually a myth that being out in the cold will give you a cold. Flus and colds are caused by viruses, not weather. And the reason an onslaught of these ailments is more common in winter is that we tend to stay cooped up indoors more, where it is easier for viruses to spread. 

Related: 3 Post-Workout Protein Snacks to Fuel Up for Cold-Weather Training

But there is a simple, Spartan-approved solution: hauling our bodies outside for regular workouts. Even as little as 30 minutes of moderate-to-vigorous exercise every day can stimulate your immune system.

4. It's a Great Way to Get Vitamin D

Vitamin D is crucial to your overall health, but it can be difficult to get it from food, especially if you’re vegan. Although it’s found in eggs, cheese, fatty fish, pork, and some mushrooms, not all diets include these foods.

The fact is, the easiest way to get your dose of vitamin D is by stepping out under the sun. Because when the sun's ultraviolet B (UVB) rays hit the cholesterol in skin cells, it causes vitamin D synthesis to occur. 

In winter months, though, tons of people tend to stay indoors more, meaning that vitamin D intake plummets. Not getting enough of this micronutrient can lead to muscle weakness, bone pain, fatigue, depression, and — in acute cases — a loss of bone density, which can contribute to diseases such as osteoporosis.

Related: 4 Things OCR Athletes Should Know About Their Bones

That’s why you need to make a conscious effort to spend at least 10-30 minutes outdoors getting some winter sun on your skin. And if you're still looking for ways to workout in the winter, you can go for a cycle, take your workout to the park or playground, or commit to a Spartan race. 

If you do live in a particularly dark winter environment, experts also recommend supplementing with vitamin D-fortified foods. Or — if your particular diet permits — the foods mentioned above. 

5. You'll Feel Better Mentally After a Winter Workout

The benefits for your well-being of being outdoors have been widely reported, and being in natural spaces and breathing fresh air has been linked to improved attention, lower stress, and better mood. But not so widely known is that while you’re outside, colder temperatures appear to have a better effect on mental health than hotter ones. 

In one paper published in the Journal of Health Economics, researchers revealed that while rising temperatures seemed to coincide with increased emergency department visits for acute stress, depression, and even suicides, cooler days made people less likely to report instances of bad mental health. 

Related: 6 Ways to Cross-Train the Hell Out of Winter + Prep for 2022 Race Season

But why is this? Well, for starters, some experts suggest that higher temperatures can be yet another thing on top of daily stresses. One report showed that when temperatures rose above 70 degrees Fahrenheit, people noted a slump in positive emotions such as joy and optimism, and an increase in moodiness, anger, and stress.  

Another reason could simply be that working out outdoors in winter makes you feel more alive. Of course, there’s science behind that, too: Feeling cold is known to stimulate the parasympathetic system, which can trigger the release of dopamine and serotonin.