The study itself compares different types of exercise (strength training and jump training) for their effects on bone density in men. I first came across Hinton’s research when I was researching my book a few years ago, and realising that the traditional wisdom on this topic – i.e. that strong bones are the result of weight-bearing exercise – wasn’t the full picture. It turns out that two other key factors make a big difference: jarring impacts, and resistance training that applies loads to the specific areas where bone density is most vulnerable, like the hips and spine.The interactions between these effects are interesting. Most studies find that strength-trained athletes have greater bone density than resistance-trained athletes. But runners also get repeated jarring impacts from each step when they run. As a result, Hinton found that runners have pretty much the same bone density – relative to their body size – as strength-trained athletes. Cyclists, on the other hand, get neither jarring impacts nor strength training, so they tend to have lower bone density.
Anyway, the basic finding of the new study is that both jumping and weight-lifting were able to increase overall bone density and lumbar spine density after six months, and weight-lifting also increased hip bone density. The twice-a-week strength training program focused on exercises that load the hips and spine, such as squats, modified dead lifts, and military press.
The thrice-weekly jumping program involved a mix of single- and double-leg jumps in various directions, off boxes, over hurdles and so on, starting with 10 reps of five different jumps and progressing. (Studies suggest that the benefits of a single jumping session max out after 40 to 100 jumps, so they did no more than 100 jumps at a time.)
The bottom line? Whether you’re a man or a woman, your bones are getting steadily weaker unless you’re doing exercises that strengthen them. If you’re particularly at risk for falls or weak bones, these are the types of exercises you might want to focus on.