Is Jogging Healthy for the Heart, or Harmful to It?

Sept. 13, 2000 -- Exercise that raisesheart rates clearly lowers the risk of stroke and heart attack. But what about those reports of joggers who die suddenly while trying to do their body good? Danish researchers have shown that joggers who stick with it have a lower risk of death than non-joggers or those who throw in the towel, according to a report in the Sept. 9 issue of the British Medical Journal. Butdoctors do urge caution for joggers who are inactive or overweight or who have heart disease or diabetes.


"Many studies have shown that physical activity has a positive effect on health, but the optimum frequency, intensity, and duration of exercise haven't yet been established," says lead author (and jogger) Peter Schnohr, MD, chief cardiologist of the Copenhagen City Heart Study. "Still, vigorous exercise like jogging is thought to be most beneficial."


Due to the public concern about deaths during jogging, researchers followed over 4,600 Danish men from 20 to 79 years of age for 10 years. Along with their medical and smoking history, participants were polled about jogging.


After accounting for high blood pressure, high cholesterol, and other risk factors for heart disease, death rates were significantly lower among regular joggers than non-joggers or those who fell out of the habit.


In fact, the American College of Sports Medicine recommends moderate aerobic exercise for 30-50 minutes three times a week or more. "But that doesn't mean you should cram it all in between Friday and Sunday," says exercise physiologist Jim Hagberg, PhD, a professor of kinesiology at the University of Maryland, in Baltimore. "Because there's not any training adaptation, weekend warriors are putting themselves at risk, especially if they've got high blood pressure."


Even well-trained athletes can run into problems, but it's much rarer. In July, a 38-year-old man died of an irregular heartbeat during Atlanta's Peachtree Road Race, a popular 10 kilometer event. It was later found that he had significant --- but undiagnosed -- heart disease.


"Cases like this tend to stay on our minds, but more people die [this type of death] when resting at home than they do during exercise," says cardiologist and veteran marathon runner Paul Robinson, MD, a 67-year-old associate professor of medicine at Atlanta's Emory University. "For most joggers, the benefit of chronic disease prevention far outweighs any risk of sudden death."


Of course, you should see your doctor before starting an exercise program if you've got heart disease or other risk factors, Robinson tells WebMD. "And even if you're healthy and under the age of 50, it's still a good idea to begin aerobic conditioning with a combination of walking and running. You don't have to monitor your heart rate, but try not to get so winded that you can't at least speak in short sentences."


A great way to build up your wind is with a beginner's schedule for runners, according to clinical athletic trainer Mary Kirkland, the supervisor of rehabilitation training at Florida's Kennedy Space Center. "It also prevents wear and tear on muscles and tendons by slowly converting from walking to running over 14 weeks," she explains. The routine assumes an exercise schedule of four days a week or more and starts out with a 20 minute walk each day. Gradually, more and more walking time is replaced by running until finally, at the 14th week and thereafter, the workout consists of 30 minutes of running each exercise day.