Why train alone when you can train with a friend?  Having a training partner fosters motivation, intesity and longevity.  If you have someone of similar goals and experience that would like to grow and succeed with you then you can sign up together and get all the benefits that come with it.  In addition to the physical mental and psychological benefits there is also a finacial one.  People training together get a reduced fee since I am instructing both during the same time.  It's a great way get your fit on!!