A Johns Hopkins study reveals that older black women who spend time with young children in the classroom are not only more active than similar women who don't volunteer, but seem to stay active.

Building on results of a 2006 Hopkins study showing that 15 hours of volunteer work a week at a grade school nearly doubled a sedentary older person's overall activity level, the new study demonstrates that the increased activity remains high for at least three years.

"This is one more piece of evidence that volunteer programs that are designed to increase the health of the volunteers can help older adults be more physically active," says Erwin Tan, Ph.D., assistant professor of geriatrics at the Johns Hopkins University School of Medicine and lead author of the study, which appeared online January 29 in the Journals of Gerontology. "Anything that increases a level of activity for a long period of time is a huge plus, but the real news here is that this particular kind of volunteer work benefits children and the educational system as well as the volunteers, demonstrating the potential benefits for what many are calling an intergenerational social contract."

Tan says the focus on black woman was due to their preponderance in two community groups from which study subjects were recruited, but he believes the results would be the same for all elderly…