“From the top of your head to the bottom of your toes, being physically active is the stimulus that gets most organs in the body to work at their best,” says Miriam Nelson, PhD, at Boston’s Tufts University. Here are some recently discovered benefits:

Heart Health: In research following nearly 40,000 women for five years, walking briskly at least one hour a week cut the chance of being diagnosed with heart disease in half.

Mental Function: Older adults who said they took part in at least four activities (such as gardening, housecleaning, jogging, or walking) during the previous two weeks were 50 percent less likely after five years to receive a diagnosis of dementia than their less active peers.

Bone Health: While most postmenopausal women lose 1 percent of their bone mineral density annually, “the group that [strength] trains either stays the same or has a slight increase” in bone strength, reports Dr. Hurley.

Pain Relief: Healthy seniors who run regularly have one quarter the musculoskeletal pain reported by more sedentary elders.

Diabetes: In one large study of more than 50,000 nurses, every hour of brisk walking a day decreased their risk for Type 2 diabetes by one third.

Weight Control: Researchers at Duke University found that, after six months, middle-aged women who jogged 17 miles weekly lost 11 pounds of fat, while nonexercisers gained approximately two and a half pounds of fat.

Stroke: “Regular aerobic exercise reduces blood pressure in about 75 percent of people,” says University of Maryland kinesiologist Ben Hurley, PhD.