The Best Form of Medicine is Exercise!

April 15, 2020

By James Goodwin, PTA, CSCS

Exercise is a fundamental component to our health and well-being, which is why staying active has been featured as a key recommendation in many Government COVID-19 strategies. In fact, moderate exercise such as a brisk walk, general gardening and even dancing will help improve your body’s immune system.

Several studies suggest that moderate exercise increases the number of lymphocytes (white blood cells) in the blood, boosting our ability to fight off infections and viruses. One would think more is better, right? You couldn’t be more wrong!

Strenuous exercise decreases the body’s natural virus-killing cells making you more susceptible to increased infection. A study conducted by Pedersen and Toft, examined the effects on the immune system following moderate and strenuous exercise. They concluded that moderate exercise appears to increase resistance to upper respiratory tract infections, whereas intense exercise decreases the immune function. It must be noted, however, the study suggests these negative effects result from intense “long-term” exercise lasting for at least an hour. In fact, Pedersen and Toft explain, “an acute bout of exercise induces mobilization of all lymphocyte subpopulations to the blood.” That is, shorter bouts of exercise as well as moderate intensity may be more beneficial than long-duration strenuous exercise.

So, what’s the take home message? Go for that walk with the dog, dance with your spouse, but keep the intensity moderate and duration short. Life is a marathon NOT a sprint, so enjoy the journey. The best form of medicine is exercise, so let’s stay active, and in doing so, stay healthy together!


Pedersen BK, Toft AD. Effects of exercise on lymphocytes and cytokines. British Journal of Sports Medicine. 2000; 246-251.

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