This week’s expert is Lauren Struszczak. Lauren has extensive knowledge of physical activity and immune function, having nearly completed her PhD at the University of Bath, after previously studying at Loughborough University. In current times her research has never been more important, so enjoy this short article about physical activity & immune function.
Key question: Does physical activity help my immune system?
What a time to be alive! It is safe to say COVID-19 has made us live in (yes, I’m going to say it…) unprecedented times. More than ever people are finding different ways to avoid infection and boost their immune systems. The good news is we can actually improve our immune system through something that you can do for free; exercise or physical activity.
This concept of ‘exercise immunology’ is by no means a new one and whether exercise boosts the immune system has been investigated and discussed numerous times, no better than in a recent review (click here), which concludes ‘exercise most likely improves immune competency across the life span’:
So how does this happen? In short, any exercise, physical activity or movement which gets the heart beating, and blood pumping faster causes an increase in certain immune cells in the blood. This subset of immune cells are excellent killers (the fancy name is cytotoxic T-lymphocytes and Natural Killer cells). These killer cells circulate the body and head to potential areas of threat like the tissues or lymph nodes, where they survey the body for infection and kill any cells that have become infected. Therefore, with every bout of exercise we also experience a bout of ‘immune surveillance’. Evidence has supported this, and it has been shown that vaccination (which assesses how well the immune system responds to invading viruses) is more effective both after an acute bout of exercise and a period of exercise training. For more information on this click here. At this point it is worth saying that there is some evidence that prolonged- strenuous exercise (e.g. marathon running) could be linked to a weakened immune system, but for most people (non-athletes) this isn’t a major concern and any physical activity we do should really help our immune system function well.
One population where exercise induced immune stimulation may be especially important is in more elderly populations. It is accepted that as we age our immune system gradually becomes less effective, a term known as immunosenescence. During immunosenescence there is a reduction in number of some of our immune cells that can respond to new ‘never seen before’ viruses (does this sound familiar at the moment?). Thankfully exercise and/or physical activity has been shown to increase the number of these cells and slow down the natural process of ageing of the immune system (click here for more information on that).
So, how much is enough? It is recommended that adults should aim for 150 minutes of moderate intensity activity per week such as walking, riding a bike or mowing the lawn. However, a good start would be to consciously move more and avoid sedentary activities such as playing computer games or sitting down for long periods of time.
The take-home message: Yet another benefit of doing moderate intensity physical activity is the effect it can have for our immune system. For all of us, and especially elderly people, trying to increase our physical activity will help keep our immune system functioning well.
Don't forget to sign up to the blog (click here) for more posts on physical activity and health. We also have some experts lined up for posts about how you might be able to become more physically active successfully (not just the benefits of doing it) and also nutritionists!! Thanks for joining us today and thanks to Lauren for sharing her knowledge!