A new study from the University of Missouri-Columbia has found that men engaging predominantly in low-impact forms of exercise like cycling have an increased incidence of osteopenia -- a condition resulting in two times the risk of bone fracture.
According to the National Osteoporosis Foundation, osteoporosis affects more than two million men in the United States and nearly 12 million more have osteopenia -- clinically significant low bone density that is less severe than osteoporosis.
"Unfortunately, some individuals who believe they are doing everything right in terms of their health might be surprised and upset by our finding," said Pamela Hinton, an associate professor of nutritional sciences in MU's College of Human Environmental Sciences, who co-authored the study. "We believe, however, that these results will ultimately serve as education and motivation for these people."
Hinton said the effects of osteopenia can be mitigated by integration of weight-bearing activities into the lifestyle of active individuals. Studies in pre- and post-menopausal women suggest that bone mineral density will increase two to three percent after six months of resistance training three times per week. Small changes in bone density translate into much larger changes in bone strength -- a one percent increase in bone density reduces the risk of fracture by up to five percent.
"Regular, non-weight-bearing activities, such as swimming and cycling are effective measures for preventing the leading risk factors for death and disability in our society," Hinton said. "But the results of this study suggest that regular weight-bearing activities, such as running, jogging, or rope jumping, are important for the maintenance of healthy bones."
The researchers measured bone mineral density in 43 competitive male cyclists and runners ages 20 to 59. Findings of the study included:
* The cyclists had significantly lower bone mineral density of the whole body, especially of the lumbar spine, compared to runners.
* 63 percent of the cyclists had osteopenia of the spine or hip compared with 19 percent of the runners.
* Cyclists were seven-times more likely to have osteopenia of the spine than the runners.
* The risk of fracture is increased approximately two-fold in osteopenic individuals and five-fold in people with osteopenia.
* Low bone density in males often remains undiagnosed and inadequately treated and, after suffering a fracture, men are less likely to receive follow-up care than women.
* Risk factors for osteoporosis in men are similar to those identified in women: family history, age, low body weight, smoking, excessive alcohol consumption, inadequate calcium or vitamin D intake, low reproductive hormone levels, physical inactivity, and disease or medication affecting bone metabolism.
The study, "Participation in road cycling versus running is associated with lower bone mineral density in men," will be published in Metabolism, and is authored by MU researchers R.S. Rector, R. Rogers, M. Ruebel and P.S. Hinton, in the Department of Nutritional Sciences.
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