The world wide events surrounding COVID 19 or the coronavirus have brought illness, hygiene, and immunity to the forefront of our minds. Immunosenescence is a term researchers use to describe the decline in our immune function as we age. These changes reduce our ability to both fight current infection and adapt or adjust to future infections. Experts believe these age related changes are responsible in part for illnesses such as age related diabetes, heart disease, and brain diseases such as Alzheimer’s. This is one of the reasons why age alone is a high risk group for the COVID 19 virus. Importantly, like most of our body’s systems, the immune system is plastic and has been shown to decrease and increase its’ function due to numerous stimuli. Interestingly, exercise has been shown not only to correlate with better immune system function (more active individuals have better immune function) but activity itself has been shown to improve immune function.
Most of the research has focused on the immune response to aerobic and resistance training in both healthy and immunosuppressed populations (ex. HIV/AIDS). Multiple authors have shown repeated bouts of exercise improve immune system function, slow the effects of immunosenescence, and reduce inflammatory markers in the body. As our understanding of exercise’s impact on the immune system evolves authors have begun to describe exercise as a form of “immunotherapy” (Sellami et al. Front Immunol. 2018). Some of the beneficial effects of exercise on immune function are linked to improved immune system cellular (monocytes, macrophages, lymphocytes, neutrophils, T cells, and B cells) strength and response to illnesses .
In the research studies, exercise modes varied from walking to cycling to running to endurance competition training. In short, exercise does not have to be vigorous but moderate intensity, relative to the individual, longer duration exercise performed 3-5 days per week is sufficient for a response. Individual’s should aim to meet national guidelines for exercise dosages. In a world full of uncertainty due to the virus we should focus on what we can control to improve our immunity including social distancing, hygiene, sleep, diet, and exercise.