A new study says taking up martial arts can keep aging at bay:

Douris' team examined the overall fitness of 18 individuals between 40 and 60 years of age. Nine of the study participants had been practicing soo bahk do, a Korean martial art similar to karate or tae kwon do, for about three years. The other nine participants maintained a more or less "couch potato" lifestyle.

Overall, the soo bahk do devotees "were much more flexible, had more leg strength, less body fat, better aerobic conditioning and better balance" compared to the sedentary study subjects, Douris reports.

The martial art practitioners had an average 12 percent less body fat than the non-exercisers, the researchers report. They also seemed much stronger -- while sedentary types could only muster up 37 sit-ups in a row on average, the soo bahk do practitioners averaged 66 sit-ups before exhaustion set in. The martial arts group also displayed more than double the balancing power of non-exercisers and outperformed the sedentary types when it came to flexibility.

The study did not compare the benefits of the martial arts to that of gym workouts, running or other fitness options. However, Douris estimates that the average soo bahk do class raises students' metabolic level -- a measurement of changes in the metabolic rate -- to about a 10, a level equal to that of jogging.