In general, activities that involve impacts with the earth, such as running and jumping, are the most effective way to improve bone health, according to Dr. Jon Tobias, a professor of rheumatology at the University of Bristol who studies bone health. They create ground-reaction forces that move through your bones and stimulate them to “remodel” themselves and add density, he said. They also entail strong muscular contractions that tug at and slightly bend attached bones, redoubling the stimulating effects of the exercise.
Sprinting and hopping are the most obvious and well-studied examples of high-impact exercises. In one recent study, women ages 25 to 50 who leaped like fleas at least 10 times in a row, twice per day for four months, significantly increased the density of their hipbones. In another, more elaborate experiment from 2006, women who hopped and also lifted weights improved the density of their spines by about 2 percent compared to a control group, especially if the weight training targeted both the upper body and the legs. Women whose weight training focused only on the legs did not gain as much density in their spines.
Interestingly, weight training on its own does not seem to be an effective way to improve bone density. A 2005 study of adult female athletes, for instance, found that those participating in the highest-impact sports, including volleyball, hurdling, squash, soccer and speed skating, had denser bones than those competing in weight lifting. But the weight lifters did have healthier bones than those in the no-impact sports of bicycling and swimming,
Thankfully for those of us reluctant to take up speed skating or hurdling later in life, the amount of pounding required to stimulate bone remodeling in older people is probably less than it is for the young. Walking may be sufficient, if it’s speedy. In the large-scale Nurses’ Health Study of more than 60,000 postmenopausal women, those who walked briskly at least four times per week were at much lower risk of hip fractures (an indirect but practical indicator of bone health) than the women who walked less often, more slowly, or not at all.
Had the walkers occasionally jigged backwards and sideways, all the better. So-called odd impacts, created when you move in a direction other than straight ahead, can initiate remodeling throughout the hipbone and spine in older people, a few recent studies suggest.
So, too, may shaking up the bones by standing on a whole-body vibration platform, available nowadays at many health clubs. In a 2013 study, 28 postmenopausal women were randomized to use a vibration platform for five minutes, three times a week, or not to shake and pulsate. After six months, the vibrating women had 2 percent more spinal bone, while the control group had lost about half a percent. Not all studies to date of vibration training show bone benefits, but none have found harms, so you might investigate the option if, because of your health, balance or natural sense of dignity, you do not hop.