Whether it’s a brisk walk, tennis match, or Pilates class, regular physical activity significantly lowers the risk of heart disease, the number one killer of Americans. The evidence for exercise is so strong, that a sedentary lifestyle is deemed a major risk factor for heart disease, alongside smoking. While most adults are aware of the benefits, only 36% of men and 21% of women meet the expert guidelines of at least 30 minutes of moderate activity daily. And many middle-aged adults wonder, “What’s the point of starting now?” After years of inactivity, can joining a gym in your 40s or 50s make a difference?

To answer these questions, researchers analyzed the exercise patterns and heart health of 791 people. As expected, life-long exercisers had the lowest risk of heart disease. Another group benefited as well—those who began working out in their forties or later reduced their risk of heart disease by 55%. These findings are detailed in the July 2006 issue of Heart .

About the Study

German researchers recruited 312 people ages 40-68 with heart disease as well as another 479 people in the same age group who were free of this disease. All 791 volunteers described their exercise habits during early adulthood (ages 20-39) and late adulthood (age 40 and over). The researchers compared exercise habits among the people with and without heart disease.

A lack of physical activity in both early and late adulthood was more common among people with heart disease than people without the disease. However, people who were inactive during their twenties and thirties, but became very active after age 40 cut their risk of heart disease about 55%. The greatest benefit—a 60% lower risk of heart disease—was seen among people who enjoyed regular exercise throughout both early and late adulthood. These statistics were adjusted to account for the effects of known risk factors, including smoking and high blood pressure.

A limitation of this study is that the researchers did not measure physical fitness, but rather relied on the volunteers to report their exercise levels from previous years. Such recall is not always accurate. Also, the study group was mostly male (86%), so it’s unclear if the benefits will be the same for women. Finally, looking back is never as good as looking forward. A more reliable study design would be to ask subjects what their exercise habits are and follow them over time to see who develops heart disease and who does not.

How Does This Affect You?

If you exercise regularly, keep up the good work. But if you don’t, these findings offer reassurance that it’s never too late to get moving. In addition to improving heart health, being active also reduces your risk of type 2 diabetes , obesity, high blood pressure , stroke , depression , and other chronic, disabling conditions.

If you’re ready to lace up your sneakers and get moving, follow these tips from the American Academy of Family Physicians:

  • Discuss with your doctor what types of exercises are safe for you.
  • Start slow, such as 10 minutes of brisk walking, and increase gradually.
  • Forget “no pain, no gain.”
  • Choose activities you enjoy to make exercise fun.
  • Exercise with a partner.
  • Sign a contract committing yourself to exercise.
  • Choose a comfortable time of day and stick with that time.
  • Write exercise appointments on your calendar.
  • Keep a daily exercise log.
  • Check your progress, for example, can you walk a certain distance faster now than when you began?
  • Consider joining a health club, many of which offer a variety of fitness machines and classes. For some people, the added cost is an incentive to exercise regularly.