Exercise Promotes Immune Function

Did you know that regular moderate exercise is one of the best ways to boost your level of immunity in the short term, and to promote ongoing optimal immune function as you age?

Well, that’s what the science shows, and in the midst of the current global Covid 19 pandemic this 2019 study from the Journal of Sport and Health Science provides a timely reminder of the compelling link between physical activity and the quality of the body’s immune defences.

The take home message from this study is that whilst it is well known that acute prolonged overly intense over training undermines immune function regular moderate daily exercise enhances it!


Here are a few really important points made by the study:

  1. Epidemiologic studies consistently show that people who are fit and engage in moderate levels of physical activity have reduced levels of inflammatory biomarkers in their body, even after adjustment for other factors such as age and body weight .

This matters, because a constant state of low grade inflammation in the body (often associated with high body fat levels and obesity) is strongly associated not just with respiratory illnesses, but with most other forms of serious chronic illness as well, including:

  • Heart and lung disease
  • Kidney disease
  • Type 2 diabetes
  • Arthritis
  • Dementia
  • Depression
  • Many forms of cancer.

And this is also why we often tell our patients that whilst there are no panaceas in health care, if there were exercise would come close!


  1. Each bout of moderate physical activity promotes improved – but transient – immunosurveillance within the body.

However, if you exercise regularly this improved level of immunosurveillance becomes the ‘new normal’, meaning that your immune system gets much better at protecting you from the potential threats and challenges it encounters every day (including nasty ‘foreign’ bugs and viruses!), whilst dampened levels of systemic inflammation also decrease your risk of developing the serious chronic illnesses mentioned earlier.


  1. Regular moderate exercise decreases immunosenescence (the poor or altered regulation of the immune system that is often seen as people age).

Again, this matters because a lot of people experience immune based problems as they age. In some cases, the immune system becomes ‘sluggish’ and less responsive to germs and other threats we all encounter every day, and in other cases the functioning of the immune system gets over reactive and ‘out of control’, driving many of the ‘autoimmune’ conditions that plague so many people.

Either way, there is evidence to suggest that regular moderate physical activity counteracts this process and helps keep our immune system functioning well as we age.


The bottom line from this research is that one of the best things you can do to maintain and stimulate healthy immune function is to participate in moderate physical activity on a daily basis! And it’s good fun as well!

But does this mean we should all rush out and start running marathons?

No – as with most things in healthcare it’s all about dose! Moderate daily activity that gets you slightly out of breath for 30 -60 minutes a day boosts immune function, but also remember that high overly intense exercise loads sustained over an extended period of time can actually undermine it, and this is why the exercise guidelines published by bodies like the NHS can be really helpful.

So, how active are you on a day to day basis, and could things be better? Have fun, stay active, and stay well.


Interesting Footnote 1: The increased risk of serious health complications due to obesity and other factors amongst Covid 19 sufferers is attracting a lot of close scrutiny. Here is the text of a message that Aseem Malhotra – UK cardiologist and health campaigner – posted on his Facebook page recently:

April 28 at 7:49 PM – ‘A very senior cabinet minister in the British government has just directly messaged me to let me know that they are seriously looking into the link between diet, obesity and Covid -19 deaths and moving forward for population health. A result ? Remember as Harvey Milk said ‘rights are only won by those who make their voices heard. Hope is never silent’ #obesity #NHS’.


Interesting Footnote 2: I have a friend who is a really good club runner, and by that I mean he gets the Great North Run done in under 80 minutes. A few years ago – after another great GNR result – I jokingly said: ‘So, a marathon next?’, to which he replied ‘No way Steve, those guys always look so chronically exhausted’. With apologies to all the marathoners out there, I had to agree.



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