Feeling SAD this winter? Here are some ways to feel better.

It happens every winter: People experience seasonal depression, known as  seasonal affective disorder (SAD). Decreased sunlight, fewer opportunities to be active outside, and overall desire to stay cozy and inside can be contributing factors—but there are things you can do to combat the winter doldrums.

One way to treat SAD is with a SAD lamp that provides light similar to sunlight. Taking a vitamin D supplement can help as well. But one of the best ways to fight SAD is to stay active.

During the winter we naturally want to make like animals and hibernate. It’s cold, the sun doesn’t shine, and we want to stay cozied up inside. Although allowing your body to rest is important, too much hibernation can lead to fatigue, trouble sleeping, and low energy in general.

Since it’s colder in the winter, your heart rate generally doesn’t get as high as it does in the warmer months when you exercise. Because of this, you generally sweat less and use less energy—which increases your endurance and can actually help you exercise longer.

You don’t have to exercise outside if it’s too cold. And if you don’t have a gym membership, you can exercise at home. Look up workout videos online and get active in your living room. Stretch. Take up yoga. Walk around the mall. In general, 30 minutes of mild activity per day is recommended, but even just ten minutes of activity will serve you well in the colder months.

If you are working out outside, be sure to dress in layers so you can allow your body to cool and sweat as you exercise. Also, be sure to keep your head covered with a hat or earmuffs: We lose most of our body heat through our head.

About vitamin D: Around 40% of people are vitamin D-deficient year ‘round, and that number increases in the winter, since the main way we get vitamin D is from the sun. Taking a supplement can help maintain healthy amounts of vitamin D in your diet. Speak with your doctor first to make sure you’re taking the correct amount.

A SAD lamp will also help you with vitamin D. And eating foods rich in vitamin D such as pork, mushrooms, and fish can help increase your levels, as well.

And remember: Spring is just around the corner. The sun and the warm days are coming back soon!