Men exercise for many reasons, including building muscle, staying slim, and maintaining healthy hearts, but they may not know there's another benefit — building bone mass.

A study conducted at the University of Missouri found that men who participated in high-impact sports, such as jogging and tennis, when teens and as young adults, had a higher bone mass in their lumbar spine and hips than those who did not.

"While osteoporosis is commonly associated with only post-menopausal women, it is, in fact, a serious issue for men as well," said UM associate professor Pamela Hinton. "Indeed, research has shown that the consequences of osteoporosis can be much worse for men, as they are less likely to be diagnosed and are at a greater mortality risk from fractures that occur as a result of a fall."

Hinton analyzed data from the physical histories of 203 males aged 30-65 years. She found that the stress on bones during exercise that helps build strong bones during adolescence and young adulthood made bones stronger as the men aged.

"The most important take-away is that if you are healthy, it is never too late to begin high-impact activities or resistance training to improve bone mineral density," Hinton said.

"While activity during skeletal growth is significant, we also saw positive associations between such physical activity and bone density at all ages.

"So, even middle-aged men who spent their teenage years sitting on the couch could see benefits from beginning a bone-strengthening exercise program."

The study was published in the American Journal of Men's Health.