After six months of daily back pain I got better by getting out and exercising. A friend of mine did the same thing but her doctor advised her to join a group. Does it really matter if exercise is done alone or in a group?

It might make a difference for some people. For example the link between back pain and depression is well known. Long-term benefits of exercise have also been shown both physically and psychologically.

A group exercise class may help depressed patients feel a sense of belonging. This kind of social support may be what helps some people the most.