'RUN' AWAY FROM COVID?!
With Covid being top of mind for us all, I thought I would lighten the mood and bring a glimmer of hope to the situation!
It’s well established that regular exercise helps to improve your immunity… But did you know that it has been scientifically proven to protect against Covid 19?!
I’ll be first in line for an exercise jab! This research study looked at 48,440 adult patients who had received a positive Covid19 result in 2020 (1). They found that being physically active was protective for Covid outcomes – making them less likely to die, be hospitalised, or go to ICU as a result of the virus. They also found that doing some exercise (even if not enough to meet the physical activity guidelines of 150 minutes per week), was still superior to no exercise at all.
That’s pretty neat, right? That exercise alone has the power to reduce the severity of Covid19 outcomes for those who are infected. Exercise provides an extra line of defense, a few more soldiers lined up to battle those pesky virus particles. There’s even the suggestion that doing a single bout of exercise several hours before having your vaccination may help improve the efficacy of the vaccine! (2)
So how does exercise help with immunity?
Exercise causes an increase in the circulation of blood around the body, and with it, a 2-3 fold increase in lymph flow through the lymphatic system (3).
Lymph fluid is a colourless fluid that transports our valuable lymphocytes, a type of white blood cell responsible for protecting us from pathogens. Lymph fluid moves around the body through a network of vessels (similar, but distinct from the blood vessels), and through the lymph nodes where the fluid is filtered.
With this increase in lymph flow comes an increase in the circulation of lymphocytes- our little soldiers (T cells, B cells, and natural killer cells) - which are constantly on alert for any foreign invaders that have entered our system. If they detect anything out of sorts, they trigger the immune response; first ‘tagging’ the pathogen (i.e. creating antibodies to help other cells identify what to destroy), then attacking it, and finally removing the waste from the system.
The process of looking out for pathogens is known as immune surveillance. Even a single exercise session helps to get these lymphocytes moving - literally billions of them! (4) - patrolling the body in search of a fight. The faster that the pathogen is identified and removed, the less chance it has to wreck havoc in the body.
This is a very simplified scientific explanation of the immune response (and there are many other immune cells and proteins involved!), but you get the idea. Exercise keeps this detection system up to scratch by keeping those immune soldiers on their toes!
How much exercise to do for immune benefits?
The recommendations are consistent with that of the general public health guidelines - a total of 150+ minutes of moderate to vigorous-intensity aerobic exercise, and 2-3 strength-based sessions, spread over the week (4). If that sounds like a lot, no stress! Remember that the Covid- specific research study mentioned above found that SOME exercise is still better than NO exercise!
The most important thing is consistency - to give you that constant extra level of protection every day.
Note: Long-duration, vigorous exercise (i.e. 60+ minutes of high-intensity exercise) may cause a period of immune suppression for several hours following the exercise bout, creating a window of increased susceptibility to infections. So if you’re already feeling slightly under the weather, high intensity exercise is best left for another day!! (5)
Happy pathogen fighting everyone!
References:
Physical inactivity is associated with a higher risk for severe COVID-19 outcomes: a study in 48 440 adult patients https://pubmed.ncbi.nlm.nih.gov/33849909/
Physical activity: A coadjuvant treatment to COVID-19 vaccination? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7937336/
Exercise and the lymphatic system: implications for breast-cancer survivors
The immunological case for staying active during the COVID-19 pandemic
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7165095/pdf/main.pdf
Exercise and well-being during COVID 19 – time to boost your immunity https://www.tandfonline.com/doi/full/10.1080/14787210.2020.1794818