Want to know another reason -- beyond those you can already think of -- why you should keep doing all those pull-ups, running all those miles, hiking all those trails, swimming all those laps, and playing all those sports? See how this one suits you: staying out of the dentist's chair.

The Journal of Periodontology reports that regular exercise can greatly reduce a person's risk of gum disease. In tests, men who put in a solid 45-minute workout three times a week were 40 percent less likely to develop gum problems than men who avoided workouts like ... well, like most people avoid the dentist.

Maintaining healthy gums is important for overall health. Numerous studies have linked periodontal disease to more serious health issues, such as an increased risk of heart disease and stroke.