Osteoporosis is a major public health threat affecting almost 44 million American men and women aged 50 and older. Most of those people are women; mainly because the “brittle bone disease” affects the elderly and women live longer, and men are more likely to have exercised, which builds up bone mass. The most common cause of osteoporosis in men is low testosterone.

So short of going through testosterone replacement therapy, what can men do to stave off osteoporosis?

A new study out of the University of Missouri found some hope in the form of weight-bearing exercises. The researchers learned that these exercises decreased the amount of sclerostin, a protein made in the bone, and increased IGF-1, a hormone linked with bone growth. Together, these biochemical changes promote bone formation, increasing bone density in men.

“People may be physically active, and many times people know they need to exercise to prevent obesity, heart disease or diabetes,” said study author Pamela Hinton. “However, you also really need to do specific exercises to protect your bone health.”

In the study, men 25- to 60-years-old who had low-bone mass were split into two groups. One group performed resistance training exercises such as squats and lunges using free weights. The other, control, group performed various types of jumps, such as single-leg and double-leg jumps. After 12 months of performing the exercises, the researchers then compared the levels of bone proteins and hormones in the blood.

“We saw a decrease in the level of sclerostin in both of these exercise interventions in men,” Hinton said. “When sclerostin is expressed at high levels, it has a negative impact on bone formation. In both resistance and jump training, the level of sclerostin in the bone goes down, which triggers bone formation.”

The other meaningful change the researchers noticed observed was an increase in the hormone IGF-1. In many ways IGF-1 is the opposite of sclerostin – it triggers bone growth. The decrease of harmful sclerostin levels and the increase in beneficial IGF-1 levels confirmed Hinton’s previous research that found both resistance training and jump training have beneficial effects on bone growth.

Men who want to stave off osteoporosis and bulk up their bone mass are encouraged to exercise regularly, targeting their bone health While cardiovascular exercises such as bicycling and swimming are beneficial to overall health, these work-outs do not strengthen the skeleton. Focus instead upon resistance training and jump training.

The research was published in The Bone Journal.