...That you can do for you health?
I have no information to back this up, besides personal experience, but i feel that stretching is the single best thing you can do.
I not talking about just touching you toes a few times, I am talking about stretching and holding every single muscle group in you body.
Stretching your calves, your hamstrings, your quads, your back, your shoulders, your chest, and your lats.
In other words, you might have to watch these videos of women stretching to get an idea of what i am talking about. I think i did most of these stretches.
After i did this, i slept better than i had in months and woke up with energy. If you are going to do one thing, stretch, then if you have energy go for a jog.