Impact Sports Increase Bone Density In Senior Athletes Says University Of Pittsburgh Study, but draws erroneous conclusions
Posted Feb 15 2007 2:58am
SAN DIEGO, Feb. 14 – Running, basketball and other high-impact sports may lead to stronger bones as people age, according to a new study presented today at the 74th Annual Meeting of the American Academy of Orthopedic Surgeons . Measurements conducted on senior Olympic athletes found that the bone mineral density (BMD) for those who participated in impact sports was significantly greater than athletes who competed in low-impact sports like swimming and cycling.
“While we know that exercise is vital as we get older, this study finds that the kind of exercise we choose can be just as important,” said Vonda Wright, M.D., lead author and assistant professor in the department of orthopedic surgery at the University of Pittsburgh School of Medicine. “The findings show that a key to maintaining strong, healthy bones as we age is to engage in impact sports,” added Dr. Wright, who is an orthopedic surgeon at the UPMC Center for Sports Medicine .
This comment by Dr. Wright is a classical non-sequitor. It is well known that high impact exercise leads to higher bone mass density. But it does not follow that higher bone mass density reduces the risk of osteoporosis. On the contrary, as shown in the book The Milk Imperative , a higher bone mass density caused by high impact exercise actually increases the risk of osteoporosis later in life.
The Pittsburgh study merely looked at the link between high impact exercise and bone mass density. It did not look at the effect this has on osteoporosis in later years, and therefore it would be false to draw any conclusions from the study in regard to osteoporosis.
The evidence that high impact exercise increases the risk of osteoporosis is overwhelming, as evidenced by peer reviewed research in mainstream medical journals. The key thing to remember is that exercise is necessary for general good health (not for the sake of your bones).
As explained in the book The Milk Imperative , no type of exercise reduces the risk of osteoporosis. You do exercise to maintain muscles and body suppleness, for stamina, for energy, for fighting many diseases, for good posture, and so on. But you don't do exercise to make bones more healthy or reduce the risk of osteoporosis – this is erroneous reasoning. This is so because doing more exercise increases bone turnover (the formation and break-down of bone). Bone turnover uses up bone-making cells and this is bad for bones. Why? Because our bodies only have a finite capacity for producing such cells. When this finite capacity is reached we are on the road to osteoporosis.
For the technically minded, bone-making cells are produced from osteoblast lineage, and this osteoblast lineage has a finite capacity for the production of osteoblasts. Hence, we get osteoporosis when we no longer produce enough osteoblasts (bone-making cells). Exercise of any kind uses up precious bone-making cells. We therefore want to be sufficiently active or do enough exercise to keep the body fit and healthy for everyday living (no more, no less).
Exactly how we do this is simple: it is just a matter of doing exercise, such as walking, running, playing sports, etc. but in moderation. Doing any kind of prolonged vigorous below-waist high impact exercise increases bone density in the short term, but this comes at a terrible price – it brings nearer the day you may get osteoporosis. Clearly, leading a physically active life is essential for general good health, but some kinds of exercise actually promote osteoporosis.