How exercise boosts the immune system
It’s March 2020 and the world is in chaos. There’s a global shortage of hand sanitizer and face masks, the grocery store racks that used to have paper towels and soap are barren and public places are empty. We’re freaking out. Everyone is researching how to stay safe and avoid infection and for once, people are taking their health seriously. But rather than isolating yourself from the outside world and wearing face masks, instead do things that will boost your immune system, to protect yourself from the inside out.
When we engage in regular exercise, we strengthen our immune system. That’s partly why studies show that individuals who regularly exercise have a 35 percent decreased risk of developing heart disease or stroke, a 50 percent decreased risk of developing type 2 diabetes and obesity, age slower, have less age-related illnesses like sarcopenia, and experience less mental health problems. Exercise makes you physically and mentally boosted.
How does exercise promote immunity?
Exercising increases the heart rate to increase blood flow around your body, which strengthens heart health and lung capacity, so that you can more efficiently transport oxygenated blood around your body. As a side effect of this, you are supporting the removal of bacteria from the lungs and airways; which helps to prevent lingering pathogens that may lead to infection further down the road.
As shown in a study published in the Journal of Sport and Health Science in 2019, when we exercise, antibodies and white blood cells (WBCs) circulate more vigorously and in higher concentrations. WBCs are our immune system cells, so increasing them helps to detect and fight infection more effectively. This is supported in a 1998 study that shows an inverse relationship between exercise and illness risk. This is partly due to the increase in immune cell activity, and partly due to the powerful anti-inflammatory effect of exercise.
When you exercise, you place your body under brief periods of stress and inflammation that result in powerful anti-inflammatory responses. This response is complex, mediated through multiple pathways that signal a number of biochemical changes including: the release of muscle myokines that stimulate the production of anti-inflammatory molecules like interleukin-10 (human cytokine synthesis inhibitory factor), an increase in fatty acid metabolism and other lipid super-pathway metabolites and improved oxygenation as mentioned above; which all contribute to reduced inflammation and enhanced immunity.
As we exercise our internal body temperature increases. The incremental temperature increase during exercise has been shown in a 2011 study to prevent the growth of harmful bacteria by increasing lymphocytes like CD8+ cytotoxic T-cell, a lymphocyte that destroys virus-infected cells. Research has also shown that an elevated body temperature helps immune cells function better, this is partly why we have a high temperature when we are sick - our body trying to fight infection more effectively!
These unique and powerful responses that occur during and post-exercise help to flush out bacteria, increase antioxidant production, regulate inflammation and fight pathogens. So rather than skipping your workout for fear of getting sick, use exercise as a non-negotiable tool to boost your immunity.