In the current study, tennis players in the creatine group experienced a slight increase in body weight after five weeks of taking the supplement, as has been reported in other studies of creatine supplementation.

"At the time I did my study, there was a lot of talk about creatine in tennis, and how supplementation was supposed to lead to enormous increases in muscle mass," Pluim told Reuters Health. "However, among the tennis players themselves creatine's popularity faded quickly. They did not like the weight gain associated with creatine supplementation and were worried about the risk of cramping."

"So I was really interested if all this commotion about creatine had a solid foundation, or whether it was just much ado about nothing. And it seems to be the latter."

SOURCE: British Journal of Sports Medicine

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The activity boost was comparable to what's been found in clinical trials aimed at getting older adults to exercise, Tan told Reuters Health. In the case of the volunteer program, he noted, the improvement in physical activity is just one of the benefits.

The work offers both mental and social stimulation for older volunteers, Tan said, while children and schools benefit from the added help. Past research has found that the program improves children's reading skills.

For the current study, Tan and his colleagues randomly assigned 113 adults age 60 and older to either the Experience Corps program or a waiting list. Those in the volunteer program worked in a Baltimore public elementary school for 15 hours per week, where they helped children with their reading skills, problem solving, and cooperation.

After four to eight months, Tan's team found, volunteers were more likely than the comparison group to have bumped up their overall activity levels. They were burning 40 percent more calories each week, on average, while the comparison group expended fewer calories over time.

Most of the volunteers were low-income African Americans, a group at particular risk of low activity levels and chronic medical conditions like diabetes and high blood pressure. It's important, Tan said, that volunteer programs reach out to these older adults.

The Experience Corps program operates in 14 U.S. cities, including Boston, Chicago, New York, San Francisco and Washington, D.C.

"These schools are so eager to get the help," Tan said.

For older adults not inclined to return to school, Tan pointed out that there are many ways to volunteer and stay active after retirement. A national program called Senior Corps, he noted, connects older adults to a range of volunteer opportunities.

SOURCE: Journal of Urban Health

Copyright © 2006 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.