Do you want stronger bones; try high impact exercise says the NY Times As we age, it was previously thought that our bones would weaken, especially in females. The fear we were exposed to was because of osteoporosis which in a small population of women, became a problem in their later years. For many years, women had been told to take a Dexxa scan which would lead to many of them being offered them a drug thought to strengthen the bones (Remember Boniva with all its side effects including strange fractures in the bones that were supposed to be strengthened?). The truth was that many women were told they had osteopenia or a loss of bone mineral even though their risk of having compression fractures in their spine was quite small. The other truth is that the current population of baby boomers has been much more active than many previous generations of retirees, resulting in fewer women who experienced compression fractures. The other concern of course is the risk of pelvic fracture from a fall, which is why many seniors use walkers, to steady their gait and reduce the risk of falling. New research discussed in the NY Times now shows that not just exercise, but high impact exercise will strengthen bones naturally. Read about it here. By GRETCHEN REYNOLDS Bones should be jarred, for their own good. Past experiments have definitively established that subjecting bones to abrupt stress prompts them to add mass or at least reduces their loss of mass as people age. What has been in dispute, however, is how much force is needed to stimulate bone — and how to apply that force in daily life. Recently researchers at the University of Bristol gathered male and female adolescents — the body accumulates bone mass rapidly at this time of life — and had them go about their daily routines while they wore activity monitors. The bone density of the volunteers' hips was also measured. A week later, the scientists reclaimed the monitors to check each teenager's exposure to G forces, a measure of impact. Those who experienced impacts of 4.2 G's or greater — though these were infrequent — had notably sturdier hipbones. Additional work done by the same researchers showed that running a 10-minute mile or jumping up onto and down from a box at least 15 inches high was needed to produce forces that great. The significance of these findings is that people should probably run pretty fast or jump high to generate forces great enough to help build bone. Unfortunately, few older adults are likely to be doing so. In follow-up experiments, the same researchers equipped 20 women older than 60 with activity monitors and ran them through an aerobics class, several brief and increasingly brisk walks and a session of stepping onto and off a foot-high box. None of the women reached the 4-G threshold — none, in fact, generated more than 2.1 G's of force at any point during the various exercises. The implications are somewhat concerning. Dr. Jon Tobias, a professor of rheumatology at the University of Bristol who led the experiments, says that while impacts that produce fewer than 4 G's of force may help adults maintain bone mass — a possibility that he and his colleagues are exploring in ongoing experiments — it's unclear what level of force below 4 G's is needed. read more