Just a bit of light exercise every week, such as walking or gardening, can reduce the risk of developing kidney stones by nearly one third, a new study finds.

Four hours of gardening, three hours of walking, or one hour of jogging every week was enough to radically reduce the risk of the painful condition, which sometimes can require surgery.

Prior research has already linked obesity, diabetes, metabolic syndrome, and cardiovascular disease with an increased chance of developing kidney stones.

Dr. Mathew Sorensen and his colleagues at the University of Washington School of Medicine studied 84,225 postmenopausal women participating in the Women's Health Initiative, which has been gathering information such as dietary intake and physical activity in women since the 1990s.

The researchers recommend three hours of average walking at 2-3 mph, four hours of light gardening, or one hour of moderate jogging at 6 mph. Also, the team found that consuming more than 2,200 calories per day increased the risk of developing kidney stones by up to 42 percent.

"Even small amounts of exercise may decrease the risk of kidney stones -- it does not need to be marathons, as the intensity of the exercise does not seem to matter," Sorensen said.

"Being aware of calorie intake, watching their weight, and making efforts to exercise are important factors for improving the health of our patients overall, and as it relates to kidney stones."