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From depression and anxiety to stress and ADHD, exercise is one of the most effective ways to improve your mental health. But that doesn’t mean exercise is a silver bullet for all mental health issues. Case in point: Seasonal Affective Disorder, or SAD, a type of depression that’s related to changes in seasons.
Also known as the “winter blues,” SAD is estimated to affect 10 million Americans. Symptoms start in the fall and continue into the winter months, sapping your energy and making you feel moody, hopeless, unable to concentrate, or unmotivated to train. Though regular exercise can be an effective way to relieve some forms of depression, SAD doesn’t respond to the release of feel-good endorphins during a long run. That’s because SAD is linked to a biochemical imbalance in the brain prompted by winter’s shorter, darker days. Researchers have found that as seasons change, a lack of natural sunlight can cause an imbalance of serotonin, a brain chemical that affects your mood. Some bodies also make too much melatonin, a hormone that regulates sleep, and not enough vitamin D, leading to symptoms of SAD.
This shift may be especially pronounced for athletes, who spend their warmer months training in the sunshine and colder months on an indoor bike trainer or treadmill, said Dr. Jacqueline Olds, Associate Professor of Psychiatry at Harvard Medical School.
“Activity itself doesn’t protect against SAD,” Olds explained. “It is the light, not the exercise, that treats SAD. Many people get the light when they’re exercising in the morning, and then they have a ‘double whammy’ against depression since exercise has anti-depressant effects as well.”
The main treatment for SAD is light therapy, or exposure to bright lights within 90 minutes of waking. Ideally, this would come from natural sunshine, so if it’s a bluebird day, Olds recommends taking advantage of it by doing a workout outside if possible.
“The bright light needs to happen first thing in the morning,” said Olds. “The thing that makes exercise so effective for SAD is not the exercise itself, it’s that it happens outdoors in the sunshine in the early morning.”
If Mother Nature isn’t cooperating, however, sitting in front of specially-designed lights while eating breakfast is an effective way to replace the sunshine that you miss during the fall and winter months. Light boxes should provide an exposure to 10,000 lux of light, and should be used for 20 to 30 minutes within the first 90 minutes of waking up in the morning. Antidepressant medicines and talk therapy can also reduce SAD symptoms, either alone or combined with natural or artificial light therapy.
Though it’s true that exercise is one of the best things you can do for your mental health, it’s also true that when SAD hits, getting out of bed, much less heading out into the cold for a run, can feel like the most impossible feat. Depression can (unfairly and incorrectly) make a person believe they’re worthless, and guilt for skipping a workout is just piling on. Be kind to yourself–your lack of energy or motivation isn’t because you’re not trying hard enough, but because your body is having a physiological response to a biochemical imbalance. It’s okay to take a day off, but if it happens often (or if your SAD symptoms are severe), discuss with your family doctor and/or mental health professional to determine a best treatment plan that will help you get back on track.