“The research is clear that exercise provides a highly effective treatment for depression,” wrote Dr. John Bartholomew, a leading researcher on the relationship between exercise and mood at the University of Texas at Austin, in an email.
However, the release of endorphins—chemicals associated with a feeling of euphoria and pain relief—probably isn’t the only reason exercise boosts mood. As one seminal study published by Duke University researchers in 2000 says, “one of the positive psychological benefits of systematic exercise is the development of a sense of personal mastery and positive self-regard,” which also likely plays a role.
Bartholomew posits that post-exercise depression may be related to how you think about exercise.
For example, you go for a run and are out of breath. Is this a positive? Does being out of breath show that I am working hard and I can feel good about this? Or, is it a negative? Does being out of breath show that I am out of shape and should be embarrassed?
Similarly, we often compare ourselves to others. Do I see them as being better athletes and more fit? Does this comparison make me feel inferior or weak?
If so, he writes, “then it is not surprising that you respond with a feeling of depression.”
Fortunately, exercise doesn’t have to suck for eternity. Focusing on positive affirmations like, “Although it is hard, I love to exercise because I know that I am getting better,” can help reframe the experience.
Also, keep track of your performance. “We tend to do a poor job of realizing how much better we get at exercise,” Bartholomew writes. Smartphone apps like RunKeeper, Endomondo, and Strava will monitor your progress so you can rejoice in seeing how quickly you improve.
The bottom line: If exercise is bumming you out and you’re not overdoing it, work on positive affirmations, and track your performance. Seeing hard evidence that you’re getting faster, stronger, or closer to a weight goal can make exercise more enjoyable.