New York, July 15 (IANS): Certain types of weight-lifting and jumping exercises, when performed for at least six months, may reverse age-related bone loss in middle-aged men, says a study.

Men gradually lose bone mass as they age, but by facilitating bone growth, these exercises may help prevent osteoporosis, a condition that makes bones weak and prone to breakage, the study detailed in the journal Bone said.

"Exercise-based interventions work to increase bone density in middle-aged men with low bone mass who are otherwise healthy," said one of the researchers Pam Hinton, associate professor at University of Missouri in the US.

"These exercises could be prescribed to reverse bone loss associated with aging," Hinton said.

The researchers studied 38 physically active, middle-aged men who completed either a weight-lifting programme or a jumping programme for a year.

Both programmes required participants to complete 60-120 minutes of targeted exercises each week.

The participants took calcium and vitamin D supplements throughout their training programmes.

The researchers measured the men's bone mass at the beginning of the study and again at six and 12 months using specialised X-ray scans of the whole body, hip and lumbar spine.

The researchers found the bone mass of the whole body and lumbar spine significantly increased after six months of completing the weight-lifting or jumping programmes, and this increase was maintained at 12 months.

Hip-bone density only increased among those who completed the weight-lifting programme.

"The interventions we studied are effective, safe and take 60-120 minutes per week to complete, which is feasible for most people," Hinton said.