STRENGTHENING the immune system in RUNNERS
Long-distance runners are known for their exceptional physical conditioning and ability to push their bodies to the limit. However, intense training regimens can compromise the immune system, making runners more susceptible to colds and flu.
The Immune System and Endurance Training
Endurance training, characterised by high-intensity workouts and extended periods of exercise, can put significant stress on the body. This stress, while beneficial for physical performance, may weaken the immune system. A growing body of research indicates that the immune system's function is temporarily impaired after intense exercise, a phenomenon known as the "open window." This window typically lasts for a few hours or, in some cases, up to 72 hours post-exercise, during which the immune system's defence mechanisms are weakened (Walsh et al., 2011).
The "open window" occurs due to various factors, including increased oxidative stress, inflammation, and a shift in immune cell distribution. These temporary immune impairments may allow pathogens, such as cold and flu viruses, to gain a foothold in the body (Gleeson et al., 2011). Therefore, endurance runners must adopt strategies to minimise the risk of infection while continuing their intensive training routines.
Key Vitamins and Minerals for Immune Health
Maintaining a robust immune system depends on several key vitamins and minerals. Endurance runners should pay special attention to the following nutrients and their sources:
Vitamin C: This powerful antioxidant helps reduce oxidative stress and inflammation. It is abundant in citrus fruits, strawberries, and green leafy vegetables (Carr and Maggini, 2017).
Vitamin D: Essential for immune regulation, vitamin D can be obtained from sunlight exposure and dietary sources like fatty fish, fortified dairy products, and supplements (Calder et al., 2013).
Zinc: Critical for immune cell function, zinc is found in foods like oysters, red meat, poultry, and legumes (Gammoh and Rink, 2017).
Iron: Iron is necessary for the production of haemoglobin, which carries oxygen in the blood. Runners can obtain iron from lean meats, fortified cereals, and dark leafy greens (McClung and Murray-Kolb, 2015).
Omega-3 Fatty Acids: These anti-inflammatory compounds are abundant in fatty fish, flaxseeds, and walnuts, and can help balance the immune response (Calder, 2013).
Strategies to Enhance Immunity in Endurance Runners
#1 Balanced Nutrition: Consuming a well-rounded diet that includes a variety of fruits, vegetables, lean proteins, and whole grains is crucial for overall health and immune function. Runners should aim to meet their daily vitamin and mineral requirements through food sources (Calder et al., 2013).
#2 Timing of Meals: Eating carbohydrates and protein within the post-exercise "open window" can help reduce the immune system's vulnerability (Walsh et al., 2011).
#3 Hydration: Staying adequately hydrated is essential for immune health. Runners should maintain a proper fluid balance, as dehydration can weaken the immune response (Sawka et al., 2015).
#4 Rest and Recovery: Prioritising sleep and rest days is crucial for immune function. Adequate rest allows the body to repair and regenerate immune cells (Simpson et al., 2017).
#5 Supplement Wisely: In cases where meeting dietary needs is challenging, runners can consider supplements. Vitamin C, vitamin D, and zinc supplements may be beneficial but should be taken in consultation with a healthcare provider to ensure appropriate dosages (Gleeson, 2013).
Conclusion
Endurance runners should aim to build a robust immune system to protect against colds and flu, especially during heavy training. Understanding the potential immune system compromises associated with intense exercise and incorporating a balanced diet rich in essential vitamins and minerals are key components. By following the strategies outlined in this article, athletes can minimise their vulnerability to illness and continue to excel in their training and competitions.
Take Care
Coach Wilson
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Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211.
Calder, P. C. (2013). Omega-3 polyunsaturated fatty acids and inflammatory processes: nutrition or pharmacology? British Journal of Clinical Pharmacology, 75(3), 645-662.
Calder, P. C., Carr, A. C., Gombart, A. F., & Eggersdorfer, M. (2013). Optimal nutritional status for a well-functioning immune system is an important factor to protect against viral infections. Nutrients, 12(4), 1181-1197.
Gammoh, N. Z., & Rink, L. (2017). Zinc in Infection and Inflammation. Nutrients, 9(6), 624.
Gleeson, M. (2013). Immune function in sport and exercise. Journal of Applied Physiology, 115(5), 1199-1206.
Gleeson, M., Bishop, N. C., Stensel, D. J., Lindley, M. R., Mastana, S. S., & Nimmo, M. A. (2011). The anti-inflammatory effects of exercise: mechanisms and implications for the prevention and treatment of disease. Nature Reviews Immunology, 11(9), 607-615.
McClung, J. P., & Murray-Kolb, L. E. (2015). Iron nutrition and premenopausal women: effects of poor iron status on physical and neuropsychological performance. Annual Review of Nutrition, 35, 521-538.
Sawka, M. N., Burke, L. M., Eichner, E. R., Maughan, R. J., Montain, S. J., & Stachenfeld, N. S. (2015). American College of Sports Medicine position stand. Exercise and fluid replacement. Medicine and Science in Sports and Exercise, 39(2), 377-390.
Simpson, R. J., Campbell, J. P., Gleeson, M., Krüger, K., Nieman, D. C., Pyne, D. B., ... & Walsh, N. P. (2017). Can exercise affect immune function to increase susceptibility to infection? Exercise Immunology Review, 23, 22-94.
Walsh, N. P., Gleeson, M., Shephard, R. J., Gleeson, M., Woods, J. A., Bishop, N. C., ... & Simon, P. (2011). Position statement part one: Immune function and exercise. Exercise Immunology Review, 17, 6-63.
