Throwing some water on the title:

“The study was cross-sectional, and thus the observed results could be explained by reverse causality, that is people who are more fatigued and have low mood may be more inactive,” Soini explained. “And there may be unobserved factors that could affect both physical activity and depression, and thus the association observed may not be causal

Actually the headline for the post here isn’t even the one used on the article, it’s the opening line but stops just before

But physical activity appears to be unrelated to other depressive symptoms, such as suicidal ideation, difficulty concentrating, and sleeping problems

Glad the other commenter pointed out the correlation can causation aspect. Personally and anecdotally, I remember being in the DEPTHS of a depression, taking every ounce of what I had to drag myself to the doctor, jsut for the doctor to tell me I just need a half hour of vigorous exercise a day and I’ll be fine. Lady, I don’t want to live let alone get out of bed. In what world do you think I’m going to get a vigorous anything in.