The immune system is a highly intricate network of cells and molecules designed to keep the body free from infection and disease. Exercise is known to have a profound impact on the normal functioning of the immune system. Performing regular exercise of moderate to vigorous intensity has been shown to improve immune responses to vaccination, lower chronic low-grade inflammation, and improve various immune markers in several diseases including cancer, cardiovascular disease, diabetes, cognitive impairment and obesity .
The ongoing COVID-19 pandemic has raised a lot of questions regarding how exercise can protect us from infection by boosting immunity. This is becoming more pertinent as many of us have restricted access to the gyms and parks where we would normally undertake exercise and physical activity regimens. Compounding this problem are the known negative effects of social isolation and confinement on immunity.
Each bout of exercise, particularly whole body dynamic cardiorespiratory exercise, instantaneously mobilizes literally billions of immune cells, especially those cell types that are capable of carrying out functions such as the recognition and killing of virus-infected cells.
The immune cells that are mobilized with exercise are primed and ‘looking for a fight.’ Their frequent re-circulation between the blood and tissues functions to increase host immune surveillance, which, in theory, makes us more resistant to infection and better equipped to deal with any infectious agent that has gained a foothold. Exercise also releases various proteins that can help maintain immunity.
In this regard, it is vitally important that we try to maintain our activity levels within recommended guidelines. Not only can exercise have a positive direct effect on the cells and molecules of the immune system, but it is also known to counter the negative effects of isolation and confinement stress on various aspects of immunity.
While exercise may not prevent us from becoming infected if exposed, it is likely that keeping active will boost our immune system to help minimize the deleterious effects of the virus, reduce symptoms, expedite our recovery times and lower the likelihood that we can infect others with whom we come into contact .
(Reference - ACSM 2020)
There are many nutrients that are involved with the normal functioning of the immune system, which is why maintaining a healthy balanced diet is the best way to support immune function. Important nutrients for effective immune function are:
No one food is recommended over another and eating a variety of foods will help to maintain a healthy balanced diet. Avoid processed foods, particulary those high in sugar. Ensure your diet is rich in fresh vegetables .
While more sleep won’t necessarily prevent you from getting sick, skimping on it could adversely affect your immune system, leaving you susceptible to a bad cold or case of the flu.
Without sufficient sleep, your body makes fewer cytokines, a type of protein that targets infection and inflammation, effectively creating an immune response. Cytokines are both produced and released during sleep, causing a double whammy if you skimp on shut-eye. Chronic sleep loss even makes the flu vaccine less effective by reducing your body’s ability to respond .
To stay healthy, especially during the influenza season, get the recommended seven to eight hours of sleep a night. This will help keep your immune system in fighting shape, and also protect you from other health issues including heart disease, diabetes, and obesity. If your sleep schedule is interrupted by a busy workweek or other factors, try to make up for the lost rest with naps. Taking two naps that are no longer than 30 minutes each, one in the morning and one in the afternoon, has been shown to help decrease stress and offset the negative effects that sleep deprivation has on the immune system. If you can’t swing a half-hour nap during the workday, try grabbing a 20-minute siesta on your lunch hour, and another right before dinner.
Smoking harms the immune system and can make the body less successful at fighting disease. Additionally, smoking is known to compromise the equilibrium, or balance, of the immune system. This increases the risk for several immune and autoimmune disorders (conditions caused when the immune system mistakenly attacks the body’s healthy cells and tissues).
Maintaining a healthy lifestyle habits contribute to overall health, supporting the body’s ability to fight infections instead of creating new problems. Healthy habits that help maintain a robust immune system include getting seven to nine hours of sleep per night, exercising, reducing stress, eating a healthy diet, not smoking, drinking alcohol only in moderation, maintaining a healthy weight, and getting underlying conditions under control.