Sports massage therapy is a great career, regardless if you are a male or female.  With many friends in both physical therapy and nutrition, I find that the industry is multi-faceted, without any particular gender preference.  In fact, I think that it may be easier for you as a male to obtain athletic clients for your sports massage therapy, with the jobs ranging from private client consulting to working with a professional sports team.  The numerous injuries that occur on the field or court lend well to a high demand for trained sports massage therapists, and you can certainly capitalize upon this as a male.  From my experience, I know there are many more male sports massage therapists that work with the male professional sports (such as football, hockey, baseball, basketball, etc.) than females because of that inherent, biological comfort level.