Swimming and Osteoporosis

I read an interesting article this morning in Outside magazine. The gist of it is that adult athletes participating in low impact sports (cycling and swimming were specifically mentioned) need to be very careful about osteoporosis. Calcium is consumed when we exercise and apparently the bones aren't triggered to grow unless they are subjected to pretty jarring impact. The kind of thing provided in sports such as running, gymnastics, etc. but not in swimming. The upshot of this is, even though we might be in great shape in many areas, our bones might be in no better shape than the average couch potato's. A study done on a college basketball team even showed they were losing bone density because they weren't getting enough calcium in their diets. Apparently the 1200 mg of calcium recommended is rarely ingested by most of us, and athletes in heavy training really need even more than that due to the loss of calcium through exercise. So, the recommendation of the article was to make sure to get enough calcium in your diet either through food or supplements and to get in some exercise in more high-impact sports. The article suggested weight lifting works, but it needs to be sets where failure is reached in eight reps. I wish I could find a link to the article on the web, but I can't. I did find this from the SPMA web site: www.spma.net/swimosteo.htm