(Center for the Advancement of Health) -- An estimated 3.5 million American women care for demented spouses or parents at home, putting their own physical and emotional health at risk. New research indicates that a simple, home-based exercise program can reduce the personal toll their caregiving takes.

The research, published in the May/June issue of Psychosomatic Medicine, reveals that the program "can successfully encourage a stressed and burdened population to engage in physical activity at levels sufficient to produce health benefits," according to lead author Cynthia M. Castro, Ph.D., from the Stanford University School of Medicine.

"The negative impact of caregiving … is likely due, at least in part, to the reduced probability that caregivers engage in preventive health behaviors such as regular physical activity," she explains.

Previous research, Castro notes, has shown that caregivers are unusually prone to such problems as depression, sleep disturbances, compromised immunity, elevated blood pressure and interpersonal strife.

Castro and her colleagues recruited 51 women, each caring for a demented relative living in the home with her. The women were at least 50 years old, not engaged in regular physical activity and providing at least 10 hours of care every week.

Each participant received an in-person counseling session with a health educator, who provided information and instruction on how to work up to a regular schedule of three or four 30- to 40-minute exercise sessions a week at home. Over the following 12 months, each caregiver/counselor team stayed in regular contact via telephone calls and mailed activity logs.

The researchers found that even though the caregivers provided an average of 71 hours of care a week, 70 percent of them adhered to their exercise program for a whole year. During this time, the amount and intensity of their exercise, as well as their knowledge of physical activity, significantly increased.

By the end of the year, the women were also significantly less depressed and stressed than before starting the exercise program. Although their actual burdens did not decrease, their perception of how burdened they felt markedly improved.

Castro's team also worked with a similar group of 49 caregivers who participated in an at-home nutrition-counseling program instead of the exercise program. Because exercise is known to improve psychological as well as physical well-being, the researchers expected to see less benefit in the nutrition group. Their findings, however, show that women engaged in the two programs were equally likely to stick with the program and experience similar improvements in their psychological well-being.

These results "confirm that long-term health promotion programs are feasible for a highly stressed and burdened population such as dementia family caregivers," Castro concludes. "The majority [of women overall] were actively involved in their home-based health promotion program for a minimum of nine to 12 months, with relatively few dropouts compared with other community-based activity intervention trials."

Much of the credit for the programs' benefits, Castro believes, should go to the frequent contact between counselors and caregivers. She proposes that "the additional social support and reduced isolation [the contacts provided] were possibly sufficient to produce the improvements noted in depression and stress." The women in the exercise group who had the most frequent contact with their counselors, she adds, also tended to adhere better to their program.

Funding for the study was provided by the National Institute on Aging.