Biking to lose weight won't weaken bones

Researchers at Johns Hopkins University say that, unlike dieting alone, exercising to lose weight doesn't reduce bone mass, even in people aged 55 and older.

In a study to be published in June in the American Journal of Preventative Medicine, the Hopkins researchers concluded:

“…after six months of aerobic exercise on a treadmill, bicycle or stepper, plus weightlifting, subjects experienced better overall fitness and fat loss without much change in bone mineral density. A more detailed analysis revealed slight gains in bone mass, of 1 percent to 2 percent, for those who exercised hardest and showed the greatest increases in aerobic fitness, muscle strength and muscle tissue.”

Fat loss through diet alone can lead to loss of bone, worsening the body's natural bone loss due to aging, a major risk factor for osteoporosis and bone fractures, according to a press release.

The Hopkins study included 104 men and women, aged 55 to 75. An active group exercised 60 minutes, three times a week, to improve major muscle groups, the heart and circulation.

“Substantial improvements were observed in active participants' body fat, and muscle and fitness levels,” according to the study. In both men and women who exercised and lost weight, overall bone density did not change, although results were mixed for women in specific sites of the hip. However, those who showed the greatest gains in fitness had modest gains in bone density at several sites, and loss of body fat was not associated with bone loss.

I don't need to worry about weight loss, but I am concerned about osteoporosis. If you're concerned about your bones, check out the Johns Hopkins site for osteoporosis prevention and treatment.