For me, after suffering with serious illness and having previously been quite fit, getting back into running was as much about building my mental strength as recovering my physical fitness. The learned ability to ride the ups and downs and to carry on when your inner voice is screaming that you can't do it, all serve not only to make you feel great in your body but also more able to make decisions and face challenges in life and business too.
The social aspect of running is also wonderful. We have recently taken part in the local Park Runs and the feeling of running in a crowd has a special buzz, just like being part of the weird and wonderful circus that is trading at festivals!
But, I would say, nothing quite beats running alone for clearing the mind and taking time out from the day. (Especially if you can pick up a latte on the way home).
Read more about the benefits of running here: Inc.