by Gabe Mirkin, M.D.
Several recent studies show that exercise helps to prolong your life by:
• strengthening heart muscle,
• increasing the ability of the heart to pump increased amounts of oxygen through the body,
• reducing belly fat, and
• increasing the diversity of bacteria in your colon.
We have abundant data to show that people who exercise live longer than those who do not exercise. Now we have the Copenhagen City Heart Study which begins to examine which sports are associated with living the longest (Mayo Clinic Proceedings, Sept 2018;93(12)). People who played tennis lived an average 9.7 years longer than people who do not exercise, compared to badminton (6.2 years), soccer (4.7 years), cycling (3.7 years), swimming (3.4 years), jogging (3.2 years), calisthenics (3.1 years), and health club activities (1.5 years). This study followed 8,577 people for up to 25 years. Twelve percent were primarily sedentary while 66 percent reported exercising regularly. Those who exercised only occasionally were not included in the data.
Interestingly, longevity did not correlate with the amount of time spent exercising. Those who worked out in health clubs (treadmill, elliptical, stair-climber, stationary bikes, and weightlifting) averaged 2.5 hours per week, while the longest-living group, tennis players, played only 1.7 hours per week. Cyclists who averaged the most time exercising per week (6.4 hours) lived six years less than the tennis players.
The authors report that the sports that were associated with living the longest are the ones that require interval training of some sort: short bursts of exercise using large muscle groups and full body movement. Another factor associated with increased longevity appeared to be the amount of social interaction of group sports (tennis, badminton, and soccer) compared to more solitary exercise (jogging, swimming, and cycling).
Exercise Strengthens the Heart
Another study showed that older men who exercise have stronger and larger hearts that supply more oxygen to their bodies (Sports Medicine, February 2019;49(2):199-219). The authors reviewed 32 studies of men over 45 years of age, comparing 644 athletes to 582 non-exercising controls. Echocardiograms showed that the athletes’ hearts had far more muscle. The stronger and bigger hearts pumped more blood and oxygen with each beat and had more beneficial heart rhythms. The older athletes maintained these heart benefits as they aged. Having the ability to supply more oxygen to your heart muscle is a major factor that helps to prevent heart attacks.
Sedentary People Have More Belly Fat
Compared to people who exercise, those who do not exercise regularly have much higher levels of fat in their liver and that fat markedly increases risk for heart attacks, diabetes, certain cancers and premature death (Obesity, Dec 20, 2017). The authors used MRI scans on 124 participants to show that the more time a person spends sitting down, the more belly and liver fat he has. They used history and mechanical accelerometers to measure how much time a person spends sitting down. See my report on liver fat below.
Exercise Increases Bacterial Diversity in your Colon
Of 37 breast cancer survivors, those with the highest level of fitness (endurance and maximal ability to take in and use oxygen) had the most different types of bacteria in their colons (bacterial diversity), regardless of how much fat they had in their bodies (Exp Physiol, Feb 14, 2019). The authors suggest that exercising regularly and more intensely can increase the efficiency with which your heart transports oxygen to your tissues, which, in turn, encourages a greater diversity of bacteria to grow in your colon.
Having more and different types of bacteria in your colon is associated with increased lifespan and freedom from diseases such as heart attacks and certain cancers (Int J Mol Sci, Apr 2015;16(4):7493-7519). Healthful bacteria turn soluble fiber into short chain fatty acids that lower high cholesterol and high blood pressure and reduce inflammation that can cause diabetes, heart attacks and certain cancers.
The more different types of bacteria you have in your colon, the longer you can expect to live. The authors tested 37 non-metastatic breast cancer survivors who were at least one year post-treatment. Those who had the highest heart and lung fitness levels (most intense exercise capacity) had significantly greater numbers of different types of gut bacteria compared to less fit participants. This shows that the people who exercise at the most intense levels have more varied colon bacteria.
Every week, studies are published that show that exercise prolongs lives, and now we are seeing studies that show the advantages of intense exercise over less-intense exercise. However, people with blocked arteries can suffer heart attacks with more intense exercise, so it is a good idea to check with your doctor before starting an exercise program or increasing the intensity of your present exercise 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.