YouDocs: The astounding power of aerobic exercise to change your future

Mehmet Oz and Mike Roizen
Dr. Mehmet Oz and Dr. Michael Roizen

The benefits of exercise have long been known — way before our modern insights into biochemistry, metabolism or the brain. The ancient Greek doctor Hippocrates said: "If you are in a bad mood, go for a walk. If you are still in a bad mood, go for another walk."

Thomas Jefferson urged that "not less than two hours a day should be devoted to exercise, and the weather should be little regarded." And the 19th-century German philosopher Friedrich Nietzsche said, "All truly great thoughts are conceived while walking." But today, we're blessed with scientific proof of the power of physical activity. Let's look at some of the most motivating new discoveries about aerobic exercise.

Aerobic exercise. You probably think of aerobics as a cross between heavy breathing and sweat — with a dash of sore muscles thrown in. It might surprise you to know that the American College of Sports Medicine defines aerobic exercise as any activity that uses large muscle groups, can be maintained continuously and is rhythmic in nature. Makes it sound so much easier — and fun. It is! And the benefits are enormous.

Fat chat. A new study published in the Proceedings of the National Academy of Science shows that aerobic exercise increases communication between fat and muscle cells. Yes, they talk to each other, and when they do, it burns fat and builds muscle. However, if you're sedentary, overweight or obese, or have stopped getting as much exercise as you used to, then the chat between fat and muscle cells falls silent. Your muscles weaken as they gather fat, insulin resistance increases, and excess glucose and fructose is delivered to your liver, causing fatty liver disease. Your risk for cardiovascular disease and diabetes goes up. The good news? The degenerative process is reversible — with aerobic exercise. 

Exercising your mind. If you want to fend off depression or simply improve your mood, once again aerobic exercise is key. A new study of more than 150,000 adults published in BMC Medicine found that, over seven years, participants who had low levels of cardiorespiratory fitness and muscle strength had 98% higher odds of experiencing depression.

Putting out the fires of chronic inflammation. Chronic inflammation, caused by eating inflammatory foods like red meats and added sugars, chronic stress, obesity, and — you guessed it -- lack of physical activity, damages cells, tissue and blood vessels and interferes with proper function of your immune system. 

Multiple studies show aerobic exercise helps you resist viral infections by tamping down excess inflammation that affects fat and immune cells. Now researchers are suggesting that maintaining a regular exercise routine may help lessen the impact of infection with COVID-19 by reducing the risk of severe respiratory distress.

What does it take to get these benefits? A Danish study found that one to around two and a half hours of aerobic exercise two to three times a week improves and protects cardiovascular health and significantly reduces the risk of death over a 15-year period. We suggest you work up to 300 minutes a week, starting slow, being consistent and having fun doing it — that's what's important. You may see measurable improvements in your cardiovascular health and strength in as little as three weeks, according to another study in the Journal of Applied Physiology.

Your next step. Amp up some of your weekly exercise. Introduce moderate to vigorous activity or just vigorous activity at least half the time you're working out. Moderate to vigorous or just vigorous activity slashes the risk of heart disease and your risk of death over 10 years; vigorous activity reduces cancer risk, according to a study in JAMA Internal Medicine that looked at more than 400,000 people. Moderate activity causes light sweating and a slight increase in heart rate or breathing; vigorous activity causes heavy sweating and a large increase in heart rate or breathing.

So step up! It's a great time to walk, run, swim (or do whatever you enjoy) into a healthier future.

Mehmet Oz, M.D., is host of "The Dr. Oz Show," and Mike Roizen, M.D. is Chief Wellness Officer Emeritus at Cleveland Clinic. To live your healthiest, tune into "The Dr. Oz Show" or visit