Something that I think most of us have discovered for ourselves: Being outdoors in a natural environment, especially exercising etc., improves mental health. A study finds "A jog through a forest can cut the risk of suffering from mental health problems and is twice as good for you as working out in the gym."

http://www.telegraph.co.uk/health/health...tal-health.html

I have noticed that when I do my near daily cardio exercise, outside, I feel refreshed; when I do it on the treadmill, I feel tired. Same time, same speed, same distance. different results.