Marathon! Me?

Q:I’ve been a couch potato, but this year I’m changing that. In January I started walking more, and I’ve been working out in a fitness center once a week since Valentine’s Day. I haven’t lost any weight, but my clothes fit a little better. Some high school friends are encouraging me to “move up” to running marathons with them to slim down and “really get in shape.” Do I have to run marathons to improve my health? I hope not!

A:The short answer to your question is no! While marathon running is at an all-time peak, neither you nor anyone else needs to run a marathon to get fit, to optimize body weight, or to get the health benefits of regular activity. You don’t have to run to get the benefit of moving (aerobic) exercise. Regular activity of almost any kind delivers some benefit, but you have to do enough for it to be beneficial. The National Runners’ Health Study (113,472 runners, of which 40 percent are marathoners) and the National Walkers’ Health Study (42,000 walkers) showed that walking can be as beneficial as running. Equivalent amounts of running and walking provide the same degree of benefit in terms of blood pressure, cholesterol, diabetes, and heart disease outcomes. The more energy walkers and runners use, the more their cardiovascular health improved up to the cutoff level, which was way less than marathon running. For example, aerobic exercisers doing 75 minutes of vigorous exercise per week (equivalent to running about 4.5 to 7.5 miles [7.2 to 12.1 kilometers] per week) have a 40 percent lower risk of heart disease and a 40 percent reduced risk of developing high blood pressure. Surprisingly, runners have about 20 percent lower risk of degenerative arthritis and hip replacement than leisure walkers. This is probably because of better joint mechanics and better weight management, as suggested by the observation that higher-mileage runners (15 to 23 miles [24 to 37 kilometers] per week) have a 16 percent lower risk of osteoarthritis and a 50 percent lower risk of hip replacement than those who run fewer than eight miles per week.

Marathoners are more prone to accidents and injuries, especially anterior knee pain, Achilles tendinitis, blistering, chafing, falls, shin splints, stress fractures, and overuse problems. Some 35-50 percent have training-related ailments. Additionally, marathoners may have depressed immune function beyond a 10-kilometer [6.2 mile] run. And, ironically, most marathoners don’t lose weight.

Some studies show a “reverse J-shaped” relationship between running intensity and health risks. This means that as the intensity of exercise increases, the risk of heart disease decreases but then rises when sustained intensity is too high. Nonetheless, should you wish to train for a marathon, a pretraining evaluation for silent heart disease is prudent, and it is better to increase training intensity gradually. The frequency and regularity of physical activity should be the initial goals. It takes the heart nine to 12 months to reach its maximal training potential. And remember, health is more than any ONE thing. Take care of all the other aspects too!

Peter N. Landless, a board-certified nuclear cardiologist, is director of the General Conference Health Ministries Department. Zeno L. Charles-Marcel, a board-certified internist, is an associate director of Adventist Health Ministries at the General Conference.