Athletes who train intensely can lose substantial amounts of calcium when they sweat, leading to decreased bone density. So authors of the study, which was presented recently at the annual meeting of the Endocrine Society, set out to see if taking calcium supplements pre- or post-workout would help fix the problem. They divided 52 male cyclists into two groups. One group took 1,000 mg of calcium along with 1,000 iu of vitamin D (which helps the body absorb calcium) 30 minutes before training. The other group took the same calcium-vitamin D combo an hour after training.
The result: Though both groups showed decreased blood-calcium levels, the cyclists who popped the supplements before breaking a sweat had much less calcium loss, said Vanessa Sherk, PhD, lead author of the study and postdoctoral research fellow at the University of Colorado Anschutz Medical Campus. The findings suggest that when a person consumes calcium makes a difference in terms of how much bone density loss they rack up.
“It’s interesting research because we already know that getting enough calcium is crucial to maintaining bone health, but this may be the first study demonstrating that timing plays a role,” says Steven Hawkins, PhD, a professor of exercise science at California Lutheran University and a fellow of the American College Sports Medicine, which partially funded the study.
So should you pop calcium pills or load up on yogurt before killing it in your cycling class? Because the results are preliminary and the study focused on a small group of hardcore athletes (not to mention all men), Sherk says that further research needs to be done before any recommendation can be made. On the other hand, future studies may prove that calcium before a workout really does shore up bones—and women in their 20s, 30s, and 40s already need up to 1,000 mg of calcium daily as well as 600 iu of vitamin D to maintain good health. So it certainly can’t hurt to chose a pre-workout meal or snack from the dairy aisle, says Hawkins. Think: yogurt and nuts, an egg-white omelet with cheese, or a low-fat milk smoothie. But skip the supplements if you can. Nutrients are better absorbed when you consume them via food sources.