"Also known as eco-therapy, green exercise simply means doing something, almost anything, outside. You won't necessarily burn more calories in nature's green gym.
But you can get substantial mental health benefits—reduced stress, depression and anger and enhanced mood and self-esteem—simply by seeking out the natural world, according to growing evidence from researchers in the U.S., Scandinavia and Britain.
In fact, in color therapy, green balances the nervous system and is believed to have a calming, soothing effect. It stimulates growth, and exposure to it is said to help those those suffering from depression, anxiety and nervousness. "