We assume you're all big Danish philosophy heads, so we don't need to tell you it was Søren Kierkegaard that said:

'I know of no thought so burdensome that one cannot walk away from it'

It's a nice line as it touches on autonomy, you can just drop it, but it really means that taking yourself out for a walk is often enough to break thought patterns and find new ones.

It seems modern science is coming round to our favorite Dane's line of thought too. A meta study (basically a study of studies) just out of the University Of Lancashire by Andrew J Clegg just found that exercise has a similar effect to anti-depressants. Not only that but it seemed to have a similar effect to psychological therapies, such as talking to a therapist.

It seems that light to moderate bouts are best and 13 - 36 sessions over a period of weeks was the sweet spot. So walking, resistance training, light jogging all work. It may be that higher intensity activities are harder to sustain meaning lower intensity leads to better adherence to a program. 

The studies weren't huge but it definitely seems like a positive correlation. Maybe linking this with the study we cited before about mixing up activities would be a good starting point if you're looking to change up mood and health. Throw in group activities so you get the benefit of community, and accountability for turning up, in there too and it seems you might be getting more than the sum of the parts.

We've always said we exercise as much for out head as our body so it's good to have some backup on that feeling.

Full paper here if you want to read it.