It's a common claim that regular exercise makes you feel better.
Not only does exercise make your body work better, it makes you feel better too.
More examples (out of hundreds):
This sounds like a likely area of placebo and self-delusion. Is there evidence that regular exercise improves the average level of mood? Is the effect widespread, or just a small subset of the population?
I am not questioning that regular exercise can make you healthier, stronger, live longerlive longer, improve your learningimprove your learning and reduce some forms of pain (and cause others!). I am challenging that it universally improves mood, on top of all this.