Stronger bones and strength training -- does it help?

Strength training works: it demonstrably makes your bones stronger. Multiple human studies show that bone density in the spine and hip rises by an average of 1 to 3 percent. That may sound small, but every percentage point contributes to protection against fractures.

The sharpest evidence comes from a study involving postmenopausal women who already had low bone mass¹. They trained twice a week for eight months under supervision. The training group gained 2.9 percent bone density in the spine; the control group lost 1.2 percent. In the hip the difference was even greater: plus 0.3 percent versus minus 1.9 percent. For people with already fragile bones, that is a meaningful difference.

Strength training also helps indirectly. It keeps your muscles stronger and reduces the risk of falls in old age. Falling is one of the leading causes of fractures, so this effect is at least as important as bone density itself. A routine of 2 to 3 times per week, with sets of 5 to 8 repetitions at 50 to 80 percent of your maximum strength, is effective and achievable at older ages as well, provided you build up gradually with proper guidance.

Safety: in the study above there was only one minor incident, a mild back spasm, and not a single fracture, even among the women with the weakest bones. An important caveat: the participants were carefully selected and always trained under professional supervision. Starting to lift heavy weights on your own at home is therefore quite different from what these studies tested.

Guidelines recommend strength training alongside medication, adequate calcium (1000-1200 mg per day) and vitamin D (600-800 IU per day) in the management of osteoporosis. In severe cases medication remains necessary; strength training alone is not enough. Walking and cycling, incidentally, are clearly less effective for your bones than strength training.