Osteoporosis is a disease of the bones that occurs when a person loses too much bone, produces too little bone or both. Though the disease is most often associated with women over 50, anyone can suffer from osteoporosis, which weakens bones and can make them more susceptible to breaks. Exercise is a great way for men and women to build and maintain strong bones in an attempt to prevent the onset of osteoporosis. According to the National Osteoporosis Foundation, weight-bearing exercises can help build and maintain bone density. But the NOF notes that men and women who have suffered broken bones due to osteoporosis or those at risk of such breaks may need to avoid high-impact weight-bearing exercises, which include dancing, hiking, jogging, and jumping rope, among others. For those whose physicians who suggest they avoid high-impact weight-bearing exercises, low-impact weight-bearing exercises can help them strengthen their bones. Such exercises may involve low-impact aerobics and using cardiovascular machines, such as elliptical trainers, stair-step machines and treadmills. Additional exercises that can benefit men and women looking to prevent or combat osteoporosis can be found at www.nof.org.