While there's no scientific evidence to conclusively 

support the neurotransmitter theory, there is plenty

to show that exercise provides stress-relieving benefits.

There are four ways in which exercise controls stress:

Exercise can help you feel less anxious—Exercise is being prescribed in clinical settings to help treat nervous tension. Following a session of exercise, clinicians have measureda decrease in electrical activity of tensed muscles. People are often less jittery and hyperactive after an exercise session.

Exercise can relax you—One exercise session generates 90 to 120 minutes of relaxation response. Some people call this post-exercise euphoria or endorphin response. Many neurotransmitters, not just endorphins, are involved. The important thing, though, is not what they’re called, but what they do: They improve your mood and leave you relaxed. 

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