We’ve known for awhile that exercise improves bone health, but unsure what effects it has on calcium absorption and loss. There have been recent studies trying to find out more.
Just last April, researchers from San Diego State published a study in which they had investigated urinary calcium excretion in two groups of men—one sedentary and the other on a “high-impact and resistance-exercise program”—in a randomized crossover study of three weeks (1). The active men were found to have “significantly less” urinary calcium loss in comparison to week of restricted activity (1).
But, we should note, an earlier study in 2007 reported that exercise actually increased calcium losses through sweating (2). Quite different than the other study, this one which was evaluating effects of calcium supplementation, came to the conclusion that supplementation should be used to correct the negative calcium balance from dermal loss from exercise (2).
What’s the deal?
While the 2009 study used exercise that was high in impact and resistance, the type of exercise in the 2007 study was cycling, an aerobic exercise not high in impact or high in resistance. One could infer that the type of exercise could have much to do with the type of results researchers get. Could it also be that resistance training has a role in improving calcium absorption and reducing calcium excretion?
1. Nemoseck T, Kern M. The effects of high-impact and resistance exercise on urinary calcium excretion. Int J Sport Nutr Exerc Metab 2009;19:162-71. 2. Martin BR, Davis S, Campbell WW, Weaver CM. Exercise and calcium supplementation: effects on calcium homeostasis in sportswomen. Med Sci Sports Exerc 2007;39:1481-6.