Exercise & Our Immune System
A normal functioning immune system can offer protection against multiple pathogens, but this protection diminishes with age and obesity. As our Western population is steadily living longer and becoming more obese, maintaining optimal immune function is essential to maintaining our quality of life.
Just one bout of exercise causes a significant and rapid mobilization of immune cells to the bloodstream. Leukocytes can increase 2 to 3 fold after a few minutes and increase up to 5 fold after 1 to several hours of exercise. Our exercising muscles also help to preserve immune function by secreting myokines, hormone-like proteins that are responsible for producing new immune cells and the maintenance of existing immune cells.
Exercising also has the benefit of reducing stress which can help preserve immunity. Individuals experiencing long-term stress and anxiety have sustained elevations in stress hormones, such as cortisol, which inhibit many critical functions of our immune system. Given the benefits spanning across multiple dimensions of our health, physical activity (PA) guidelines provided by many governing bodies throughout the world, recommend 150 to 300 minutes of moderate- to vigorous-intensity cardiorespiratory PA per week and 2 sessions per week of muscle strength training.
Sources:
Baker, Forrest L., Simpson, Richard J.(2021). Exercise to Support Optimal Immune Function. ACSM's Health & Fitness Journal, 25(1), 5-8.
Physical Activity Guidelines for Americans, 2nd edition (currently supported by the American College of Sports Medicine and the Centers for Disease Control and Prevention).
