by Gabe Mirkin, MD
Dramatic results in a new study from the Cleveland Clinic show that:
• You can’t be too fit: Elite athletes who do tremendous amounts of exercise have a much lower risk of dying than non-exercisers.
• Exercise is healthful: Not exercising is worse for your health than smoking, diabetes or heart disease.
The vigorous exercisers had nearly a 500 percent reduced risk of death during the study period, compared to the non-exercisers (JAMA Network Open, Oct 19, 2018;1(6):e183605).
More than 120,000 patients, average age 53, were given an exercise stress treadmill test between 1991 and 2014 and were followed up at the Cleveland Clinic. The researchers used the stress test results to classify their fitness level as low (the bottom 25th percentile), below average (25th to 49th percentile), above average (50th to 74th percentile), high (75th to 97.6th percentile), and elite (above 97.7th percentile). By January 1, 2018, 13,637 of the participants had died.
The study results were overwhelming. The more fit a person was, the less likely he was to die. There was no limit to the increase in benefits from improving fitness to very high levels. The elite athletes had an 80 percent reduction in risk for death. The greatest differences were seen among patients who had high blood pressure in the high and elite groups compared to those in the low fitness group. The lead researcher concluded, “We found that there was no ceiling for benefit . . . with no toxicity at the higher end.”
Can Extreme Amounts of Exercise Be Harmful?
This new study counters the findings of earlier studies on elite athletes that suggested they are at increased risk for irregular heartbeats, increased arterial plaque size or thickened heart valves.
• Even though master athletes may be at increased risk for irregular heartbeats (atrial fibrillation), they can still benefit from continuing to exercise. Compared to non-exercisers, they appear to be at reduced risk for suffering from serious side effects such as clots. See Irregular Heartbeats in Senior Athletes and Exercisers.
• Elite athletes may be at increased risk for larger plaques in their arteries than non-exercisers, but narrowing of arteries by plaques does not cause a heart attack. Heart attacks are caused by plaques breaking off from arteries, and exercise helps to prevent heart attacks by making plaques more stable and less likely to break off. See Exercisers Have More Stable Plaques.
• Vigorous exercisers may be at increased risk for thickened heart valves, but compared to non-exercisers, athletes with thickened heart valves still have stronger heart muscles so that they are less likely to suffer heart failure. See Exercise to Prevent a Heart Attack
Exercise Reduces Inflammation
Aging is associated with inflammation, an overactive immune system. Your immune system is supposed to kill germs when they attack you, but as soon as the germs are gone, your immunity is supposed to dampen down. However if your immunity stays active all the time, it attacks you in the same way that it kills germs. It can punch holes in arteries to cause plaques, break off the plaques to cause heart attacks, destroy your DNA to cause cancer, cause various auto-immune diseases and so forth. As you age, inflammation increases to cause loss of muscles and bone, osteoarthritis, loss of cell function associated with aging, and other harmful effects. Exercise helps to dampen down inflammation, and thus helps to prevent diseases and prolong life. One study of 111 women, ages 65 to 70, showed that replacing 30 minutes of sitting time with the same amount of time in light or moderate exercise very significantly reduced markers of inflammation (C-reactive protein and fibrinogen) and diabetes (Medicine & Science in Sports & Exercise, July 2018).
Intense Exercise is More Beneficial than Casual Exercise
This new study agrees with many earlier studies that have shown greater benefits from vigorous exercise than from low-intensity exercise:
• The SUN Study on 18,737 middle-aged people showed that those who exercise intensely have half the rate of heart attacks as those who did the same amount of exercise less intensely (Am J of Cardiology, Sept 11, 2018).
• Increased time spent exercising intensely gives adolescents a healthier metabolic profile than more time spent just exercising (PLOS Medicine, Sept 2018; 15 (9): e1002649).
• Vigorous exercise is associated with a much lower rate of metabolic syndrome and diabetes, compared to low-intensity exercise (American J of Prev Med, April 2017;52(4):e95–e101).
I think everyone should have a regular exercise program, and it is never too late to start. See How to Start an Exercise Program. Do not start an intense exercise program until you have spent several months exercising at a casual pace.
Socialization usually improves the length of time, intensity and enjoyment of exercise, so it is best to join a group, exercise with your mate, or do your exercise regularly with friends (Am J Alzheimer’s Dis Other Demen, June 2014; 29(4): 372–378).
CAUTION: Intense exercise can cause a heart attack in a person who has blocked arteries or heart damage. Check with your doctor before you start a new exercise program or make a sudden increase in the intensity of your existing program.
Gabe Mirkin, M.D., is a sports medicine doctor and fitness guru. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin has run more than 40 marathons and is now a serious tandem bike rider with his wife, Diana. His website is http://drmirkin.com/. Click to read Gabe's full bio.