Medical Compass: If not for weight loss, then why exercise?

By David Dunaief, M.D.

Last week, I wrote that we should not rely on exercise for weight loss. Exercise is still important, though. It can alter how our genes express themselves and improve our outcomes with diseases and other health issues, such as diabetes, kidney stones, osteoarthritis, cardiovascular disease and breast, colorectal and endometrial cancers (1).

Despite all the positives, it can be difficult to motivate yourself to exercise. However, there are some simple ways to motivate yourself during exercise. One study showed that those who repeated positive mantras to themselves during exercise were able to persist for longer periods (2).

Why is this so important? Because we are too sedentary, and this is the time of the year when we are especially so. According to data from the 2015-2018 Behavioral Risk Factor Surveillance System, the Northeast had among the highest levels of physical inactivity in the U.S., at 25.6 percent of the population (3).

Does exercise alter your genes?

While it may not change our genes, exercise may change how our genes express themselves.

One study’s results showed that thousands upon thousands of genes in fat cells were affected when participants exercised for six months (4). During the study, sedentary men exercised twice a week at a one-hour spin class. According to the researchers, this affected genes that are involved in storing fat and in risk for subsequent diabetes and obesity development. The participants also improved other important health metrics, including their cholesterol, blood-pressure, fat percent and, later, their waist circumferences.

The effect identified on the fat cells is referred to as epigenetics, where lifestyle modifications ultimately lead to changes in gene expression, turning them on and off. This has been shown with dietary changes, but this is one of the first studies to show that exercise also has significant impacts on our genes. It took only six months to see these numerous gene changes with modest amounts of cardiovascular exercise.

Want more encouragement? Another study showed considerable gene changes in muscle cells after one workout on a stationary bike (5). Yet another introduced six weeks of endurance exercise to healthy, but sedentary, young men and identified an abundance of genetic changes to skeletal muscle, which has broad impacts on physical and cognitive health (6).

Can you treat cardiovascular disease with exercise?

What if we could forgo medications for cardiovascular disease by exercising? One meta-analysis examined 57 studies that involved drugs and exercise. It showed similar benefits in mortality with secondary prevention of coronary heart disease with statins and exercise (7). So, in patients who already have heart disease, both statins and exercise reduce the risk of mortality by similar amounts. The same study also showed that for those with pre-diabetes, it didn’t matter whether they took metformin or exercised – they had the same effect.

While these results are exciting, don’t change your medication without consulting your physician.

Does exercise help with kidney stones?

Anyone who has tried to pass a kidney stone knows it can be excruciating. Most treatments involve taking pain medication and fluids and just waiting for the stone to pass. Truly, the best way to treat kidney stones is to prevent them.

In the Women’s Health Initiative Observational Study, exercise reduced the risk of kidney stones by as much as 31 percent (8). Even better, the intensity of exercise did not change its beneficial effect. What mattered more was exercise quantity. One hour of jogging or three hours of walking got the top results; however, lesser amounts of exercise also saw substantial reductions. This study involved 84,000 postmenopausal women, the population most likely to suffer from kidney stones.

Does sexual activity count as exercise?

We have heard that sex is a form of exercise, but is this a myth or is there actual evidence? According to research, this may be true. In a study, researchers found that young, healthy couples exert 6 METs — metabolic energy, or the amount of oxygen consumed per kilogram per minute — during sexual activity (9).

How does this compare to other activities? We exert about 1 MET while sitting and 8.5 METs while jogging. In terms of energy used, sexual activity can be qualified as moderate activity. Men and women burned almost half as many calories with sex as with jogging, burning a mean of 85 calories over about 25 minutes. Who says exercise can’t be fun?

Movement and exercise not only help you feel better, they may also influence your genes’ expression. In certain circumstances, they may be as powerful as medications in preventing some diseases.

References:

(1) JAMA. 2009;301(19):2024. (2) Med Sci Sports Exerc. 2013 Oct 10. (3) cdc.gov. (4) PLoS Genet. 2013 Jun;9(6):e1003572. (5) Cell Metab. 2012 Mar 7;15(3):405-11. (6) Mol Metab. 2021 Nov;53:101290. (7) BMJ. 2013; 347. (8) JASN. 2013;24(3):p 487-497. (9) PLoS One 8(10): e79342.

Dr. David Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.