Another reason to get your hands dirty

December 29, 2008

The Centers for Disease Control and Prevention and the American College of Sports Medicine recommends at least 30 minutes of moderate-intensity physical activity on most days of the week in order to maintain and improve optimal health. This recommendation is especially important for older Americans, who can be less likely to fulfill this requirement, yet are more at risk for chronic diseases associated with aging.

Gardening is a very popular leisure activity for adults aged 65 or older in the United States. A recent study conducted by Sin-Ae Park, Candice Shoemaker, and Mark Haub of Kansas State University, set out to determine if gardening enables older adults to meet the physical activity recommendation set forth by the CDC and the ACSM. A previous study concluded that gardening results in improvement in mental health and depression for participants. Researchers were now interested in finding out if gardening can offer subjects the same positive health benefits that regular physical activity (such as jogging, swimming, or weight training) provides.

Gardening was expected to influence whole-body bone mineral density because it included weight-bearing motions such as pushing a mower, digging holes, pulling weeds, carrying soil, and other tasks required use muscle groups in the entire body. The study was conducted on 14 gardeners aged 63-86 years. Measurements taken by researchers included heart rate, oxygen intake and energy expenditure, and the participants also kept weekly logs of their gardening activity. The study also sought to determine the average amount of time that gardeners spent at their task per week. Subjects reported, on average, gardening about 33 hours per week during May, but averaged only 15 hours per week in June and July.

Older adults are at a higher risk for a sedentary lifestyle, which is one of the factors of increased risk of decline of muscular strength and endurance, flexibility, balance, and cardiopulmonary health. One of the factors cited that makes these adults less likely to participate in physical activity is boredom during exercising. The variety of tasks associated with gardening is one reason older adults are more likely to stick with their regimen; gardening tasks change throughout the season and different activities are involved in daily chores.

The researchers concluded that gardening is a great way for older adults to meet the physical activity recommendations set forth by the CDC and the ACSM. One limit the study found was the seasonal nature of gardening. In climates where there are defined seasons, time spent gardening or maintaining a yard in winter is less than in the warm growing season. Continued research is needed to investigate the healthful benefits of gardening in all the regions of the United States.

The complete study and abstract are available on the ASHS HortTechnology electronic journal web site: http://horttech.ashspublications.org/cgi/content/abstract/18/4/639 .

Source: American Society for Horticultural Science