Keeping your immune system strong is vital for maintaining good health. This system works to defend your body against infectious agents such as bacteria, as well as abnormal cell development. Maintaining a healthy lifestyle supports the immune system, and exercise in particular has a positive effect on you immune system's function. In fact, moderately-intense physical activity, such as brisk walking, can play a pivotal role in strengthening your immune system.
Reduces Stress Hormones
Stress doesn't just ruin your mood -- it also has a negative affect on the immune system. Stress causes your body to release "fight or flight" hormones such as epinephrine, also known as adrenaline. These physiological responses to stress can suppress the immune system's function, resulting in increased vulnerability to infection. Engaging in moderately-intense physical activity keeps stress hormone levels from rising, notes the President's Council on Physical Fitness and Sports Research Digest, adding that regular exercise can provide periodic boosts to the immune system and lower your risk of getting sick.
Reduces Cold Risk
Taking part in regular physical activity also reduces your chances of coming down with a cold, according to MedlinePlus. The theory is that exercise may help your lungs get rid of the harmful agents that cause colds and other respiratory infections. Exercise also plays a role in reducing the amount of sick days attributed to colds, notes a December 2008 article in the "Clinical Journal of Sport Medicine."
Faster Immune Response
Exercise can help your immune system respond faster to bacteria, viruses or other harmful agents. The physical activity causes your body to release white blood cells and antibodies, which are involved in defending the body against infection, more quickly. This faster response helps the immune system detect invading agents before they cause infection. Increased blood flow during exercise may also be involved in improving the immune system's response to infectious agents. These faster immune responses could explain, at least in part, why people who exercise regularly tend to not get sick as often as those who are sedentary.
Improves Immunity in Aging Adults
Your immune system does not function as well when you get older. Reduced production of antibodies and changes in immune cells result in a weaker, less effective immune response in aging adults. Research, however, shows that regular exercise can strengthen immunity as you age. The 2008 study published in the "Clinical Journal of Sport Medicine" found that aerobic activity improves immune response and decreases chronic inflammation, which is an immune response. Vigorous or strenuous activity, however, may have a negative affect on the immune system, so it's best to stick with moderate exercise.
References
- President's Council on Physical Fitness and Sports Research Digest: Does Exercise Alter Immune Function and Respiratory Infections?
- MedlinePlus: Exercise and Immunity
- "Clinical Journal of Sport Medicine"; Is Regular Exercise a Friend or Foe of the Aging Immune System? A Systematic Review; DA Haaland, et al.; November 2008
