Even if you only start to exercise after age 40, you can still greatly reduce your risk of heart disease, suggests a study in the current issue of Heart.

German researchers interviewed 312 people, aged 40 to 68, with coronary artery disease and 479 healthy people in the same age group. Participants were asked about their level of physical activity in early adulthood (ages 20 to 39) and in late adulthood (after age 40).

According to the University of Heidelberg team, about half of the people with heart disease and 70 percent of the healthy volunteers said they'd been moderately or very physically active during early and late adulthood.

People who'd been active all their lives were about 60 percent less likely to have coronary heart disease. The study also found that people who became very physically active after age 40 were about 55 percent less likely to be diagnosed with heart disease than people who'd been inactive their entire lives.

While people who've exercised all their lives are more likely to enjoy better health, these findings suggest that beginning to exercise later in life still offers many benefits and can reduce the risk of heart disease, the study authors concluded.