No one looks forward to winter when cold viruses circulate more, and we spend more time indoors, where they spread more easily. Mostly, the common cold is a nuisance that stays around for a week or so and disappears. However, some upper respiratory viruses leave you with a dry cough that persists even after the cold leaves. Colds are caused by one of a variety of viruses that infect cells in the upper respiratory tract, and so far there is no cure. The best defense? Keep your immune system healthy, wash your hands, and avoid sick people. Practice healthy lifestyle habits too! One lifestyle habit that can benefit your immune system is exercise. Is there evidence that exercise can prevent the common cold? Here, David Reagan, an Atlanta-based personal trainer, answers this question in detail.
What Science Shows about Exercise and the Common Cold
A study published in the British Journal of Sports Medicine found that exercise may have protective benefits against pesky cold viruses. The study found that healthy adults who exercise at a moderate intensity or greater most days of the week enjoyed a 46% reduction in days they sniffled and sneezed because of colds and upper respiratory viruses. They also found that the exercisers had less severe cold symptoms and their symptoms didn’t stick around as long. Being older, male gender, and eating lots of fruit also reduced the risk in this study.
Based on this study, if you meet the recommended guidelines for exercise — at least 150 minutes of moderate-intensity exercise each week — you may be at less risk of developing a bad case of the sniffles, and if you get a cold, it may be less severe and clear up faster.
The Dose of Exercise Matters
Exercise in moderation seems to be best for lowering your odds of catching a cold. In fact, too much exercise, especially frequent high-intensity exercise, may have the opposite effect. It can suppress the immune response to upper respiratory viruses. Plus, over-exercising causes the adrenal glands to produce more of the stress hormone cortisol. Another function of cortisol is to suppress the immune system. Therefore, more exercise isn’t necessarily better if you’re trying to ward off colds.
How much exercise is too much? The magic number, based on some studies, is 90 minutes. Exercise at a moderate intensity for 90 minutes or longer is enough to cause a more sustained rise in cortisol. However, there is some variability, depending on factors like age, health status, and how physically fit and well-trained the person is.
What explains the benefits? Studies show that moderate exercise boosts the activity of natural killer cells, immune cells that fight viruses. This benefits you. However, too much exercise and a rise in cortisol may increase the susceptibility to upper respiratory viruses. For example, studies show that marathon runners are at higher risk of developing a cold for up to two weeks after running 26.2 miles. No surprise there! That’s a lot of stress on the body.
Eat a Snack After Each Workout
So, now you know the routine. Moderate amounts of exercise increase your immune system’s ability to fight viruses. Over-exercising causes a more sustained rise in cortisol and that makes it easier for upper respiratory viruses to gain a foothold. If you must do an exhaustive workout, eat a snack that contains 3–4 parts carbohydrate to protein afterward. Some studies show that consuming carbohydrates after a workout blunts the release of cortisol. Also, make sure you’re giving your body the nutritional support it needs to sustain exercise. Sleep is part of the equation too. Research shows that getting less than 6 hours of sleep per night suppresses immune function and increases susceptibility to colds.
The Take-Home Message:
Consistent, moderate-intensity exercise offers many health benefits and it also may lower your risk of catching a common cold but don’t go overboard. Training hard and long every day may have the opposite effect and suppress your immune defenses against cold viruses. So, train smart and make sure you’re eating a nutrient-dense diet and sleeping at least 7 hours per night. It matters!
About David Reagan
David Reagan is a NASM Certified personal trainer from Atlanta, GA, who specializes in weight loss, personalized workout plans, bodybuilding, and nutrition. He caters to high-end clients and executives, helping them achieve their fitness goals by accommodating their busy schedules. The client’s needs come first, and David’s fitness plan will set you up on the path to success.