As a result of the current COVID-19 crisis many of us are looking for ways to stay healthy and boost our immune system. Regular exercise and a healthy diet can have a positive effect on our immune system, but did you know that some types of exercise can actually weaken your immune system? This article will highlight the effect of exercise on our immunity and propose strategies to help you get the most out of your exercise routine.
Moderate intensity exercise
Exercise performed at less than 60% then maximal heart rate (HR) and performed for less than one hour is considered moderate intense exercise. Exercise that best fit that category would be:
- Brisk walking
- Light jogging
Our immune system responds positively to this type of exercise by temporarily increasing the circulation of molecules such as immunoglobulin and neutrophils which play a critical role in immune defense. It even has been shown to improve our body’s ability to recognize and destroy viruses or bacteria that can cause disease.
High Intensity exercise
Exercises performed at greater than 60% of maximal HR and/or for greater than one hour are considered high intensity exercise. Exercises that best fit this category would be:
- High intensity interval training (HIIT)
- Strength training
High intensity exercise can lead to a transient immune dysfunction by temporarily reducing the metabolic capacity of white blood cells. Thus, one should be more vigilant to avoid possible exposure to pathogens such as COVID-19 following a bout of high intensity exercise due to the transient immune system dysfunction that is associated with this type of exercise.
High intensity exercise also provides a number of benefits such as improving cardiovascular, metabolic, and mental health in ways that cannot be achieved through the participation of moderate intensity exercise alone. The physical activity guidelines for Americans recommends for adults to participate in at least 150 minutes of moderate intensity exercise and 75 minutes of high intensity exercise spread out throughout the week. They also recommend for adults to engage in two bouts of strength training per week. Which brings us to the question, how do I reap the benefit of exercise while minimizing its negative effects?
Optimize your recovery
In order to minimize the negative effect of high intensity exercise on the immune system it is vital to optimize your body’s ability to recover from each bout of exercise. While there are many expensive gadgets and supplements that claim to improve recovery, the two most effective tools are both low cost and accessible to everyone. Those recovery methods are sleep and nutrition.
Sleeping habits alone have been shown to affect the immune system. When poor sleeping habits are combined with regular high intensity exercise the negative impacts on the immune system are even more severe. As per CDC recommendation, adults should sleep between 7-9h per night. To maximize sleep quality is is recommended to:
- Stick to a sleeping schedule
- Avoid alcohol, caffeine and heavy meals in the evening
- Sleep in a cool, quiet and dark room
To optimize immune system recovery after intense exercise, studies suggest increasing the intake of carbohydrates and foods containing polyphenols. Polyphenols or antioxidants can be found in a variety of foods such as:
- Fruits – blueberries, apples, cherries and grapes
- Vegetables – artichokes, spinach, red onions
- Dark Chocolate
- Black and green tea
When starting an exercise program to boost your immune system and improve your overall health, make sure to consult with a qualified professional such as those at Paspa Physical Therapy to maximize the effectiveness of your program and minimize risk of injuries.
By: Hugo Verdi Forti, DPT
- Nieman, David C., and Laurel M. Wentz. “The compelling link between physical activity and the body’s defense system.” Journal of sport and health science 8.3 (2019): 201-217.