Our immune system has two vital roles. One is to protect us from danger, such as infections and preventing cancer cells from taking hold. The other is its significant function in repairing our tissues and helping our cells “take out the garbage” on a regular basis. The immune system uses inflammation as the primary weapon in both these functions, but it must be held in impeccable balance for us to stay healthy. Too much inflammation, and we develop chronic diseases such as arthritis, diabetes, dementia and heart disease, among others. Too little, and we’re more susceptible to infections and cancers (see illustration). The good news is that we can tune up our immune system through modifying personal behavior, such as via healthy eating. So, too, does exercise play a role in immunologic health.
Most are familiar with the public health recommendations for physical activity and exercise to improve our health. Indeed, the benefits of exercise are indisputable; many studies demonstrate that physical activity is associated with reduced rates of heart disease, stroke, diabetes and dementia. Plus, it helps us achieve and maintain our weight. An underlying principle of exercise and health is that there’s a subtle relationship between the amount of exercise we get and the health benefits we receive. Moderate exercise is most beneficial, inactivity is deleterious and extremes of exercise are not just more of a good thing — they can be harmful, as well. The same relationship exists between exercise and immune health.
[See: 6 Ways to Train Your Brain for Healthy Eating.]
The first question you might have now is: “What’s the evidence?” And the second is: “How much exercise is just right?”
[See: 13 Best Fish: High in Omega-3s — and Environmentally-Friendly.]
Evidence That Physical Activity and Exercise Affects our Immune Response
Experiments in mice have demonstrated that if you train one group to take leisurely jogs for 20 to 30 minutes and another to run for two hours over several days, and then challenge both groups with the flu bug, 70 percent of the hard-exercising mice die, while 88 percent of the moderate exercisers survive. Similarly, in humans, most clinical experiments examining colds and flus in elite runners and rowers have shown an impressive increase in respiratory infections in and around competition times when they’re exercising at their peak. Other studies have shown that frequent brisk walking can reduce the number of sick days by over half within three to four months. Collectively, these results support the “J curve” relationship between physical activity/exercise and immune health.
How Can I Start Exercising My Way to Immunologic Health?
For those of you starting to do the math right now, you may wonder what type of exercise we’re talking about and how frequently and how long you should be doing it. To begin with, I’ll be honest and tell you that a precise exercise prescription for immunologic health does not exist. But I’ll share what I do myself, plus what I tell my patients who come to see me from all over the world for various problems with their immune systems. I start by reminding my patients that the current public health guidelines for physical activity tell us that we should aim for 150 minutes per week of moderate exercise activities, such as brisk walking, gardening, dancing or some combination. I find this comforting; if you’re currently inactive, this goal is approachable and certainly doesn’t require you to join a gym or hire a personal trainer. I believe strongly that walking is both exercise and medicine. I also believe that, just as for many health-oriented behaviors, we can start off with tiny amounts. I like to tell my most inactive patients that we’ll start with “an eye dropper” of exercise to start.
A number of years ago, the late Dr. Toni Yancey performed some important research on physical activity and population health. He later wrote a book, “Instant Recess,” that influenced me greatly. Dr Yancey’s work clearly demonstrated that for inactive populations, you could improve their group health by introducing physical activity (i.e. walking in place or calisthenics) by starting with as little as three minutes a day. Now, that’s something almost everyone can do. More recently, some interesting research from the University of Colorado demonstrated that in a population of couch potato office workers, introducing six bouts of five-minute brisk walking throughout the day was more effective than a 30-minute daily gym-like workout for overall health, including improving mood and decreasing fatigue. While immune health was not measured, I recommend this type of approach in my immunology practice.
[See: 9 Ways to Boost Your Immune System.]
The bottom line is to get up and move, and don’t be embarrassed by how inactive you are now. If you start with a minute a day and increase by a minute per week, in five months you’ll be exercising 20 minutes per day.
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How to Train and Maintain Your Immune System originally appeared on usnews.com
