This Is How Much Exercise You Need to Beat Seasonal Depression
It’s not a scary number!
Do shorter days and blustery temperatures have you feeling down? It’s totally normal—seasonal affective disorder (SAD) is a form of depression that comes and goes with the seasons. Symptoms typically emerge in the late fall and early winter, and can include a whole bevy of things, like difficulty sleeping, hopelessness, and low energy.
Well, science comes bearing good news: The answer to your blues might lie in a consistent exercise schedule. According to a study published in the journal Depression and Anxiety, individuals who engaged in recurring exercise each week were less likely to be diagnosed with depression, even in the face of high genetic risk for the disorder.
The researchers at Massachusetts General Hospital (MGH) recorded data from nearly 8,000 participants in the Partners Healthcare Biobank. After patients filled out a survey about their lifestyle habits (including physical activity), their health data over the next two years were analyzed in order to identify diagnoses related to depression. They also calculated genetic risk scores for each participant, combining information across the entire genome into a single score that reflected a person's inherited risk for depression.
They found that people who were more physically active were less likely to develop depression, even after accounting for genetic risk.
"Our findings strongly suggest that, when it comes to depression, genes are not destiny and that being physically active has the potential to neutralize the added risk of future episodes in individuals who are genetically vulnerable," said Karmel Choi, PhD, researcher at the Harvard T.H. Chan School of Public Health and lead author of the study.
This makes sense–according to Eudene Harry, MD, board-certified medical director for Oasis Wellness and Rejuvenation Center in Orlando, Fla.: “Moderate to high-intensity workouts can lead to an increase in endorphins that elevate our moods temporarily. Research has also shown that consistent aerobic exercise increases the size of the hippocampus, which is associated with a reduced risk of depression.”
So exactly how much physical activity is needed to reduce the risk of future depression? According to Choi, the magic number is around 35 minutes per day (or four hours each week).
Researchers also found that both high-intensity forms of activity, such as aerobic exercise, dance, and exercise machines, and lower-intensity forms, including yoga and stretching, were equally effective at decreasing ones odds of depression. Overall, individuals could see a 17 percent reduction for each added four-hour block of activity per week.
“The exercise that works is the type that you do on a consistent basis, so I suggest picking things that you enjoy," says Dr. Harry. "Whether it’s hiking, gardening, or biking, the key is to get your heart pumping. Social interaction also adds another thing to the equation to help fight depression, so activities like a fun dance class, hiking with friends, or a game of basketball can do wonders."
While Choi says they acknowledge that strategies to combat depression remain limited, they hope their promising evidence can lower the risk of depression, especially when there is a family history.
"We believe many factors could be part of an overall strategy for improving resilience and preventing depression," Choi notes. "The magnitude of depression around the world underscores the need for effective strategies that can impact as many people as possible."