Exercise and the immune system

Exercise, as we all know, is an essential part of our physical and mental well-being. And with the COVID-19 running rampant, health officials are still telling us to still exercise daily – why is that?

Many have shown the benefits of exercise to pain, cardiovascular health and our brain. Our immune system, as quoted by my biology teacher, is “magic”. It works tirelessly preventing a whole range of conditions and diseases day in, day out. We know that diet, sleep, age and genetics influence our immune system – but so does exercise.

The effect of exercise on our immune system is still being researched with many articles suggesting new mechanisms of how this occurs. We will quickly discuss what benefits and potential risks exercises pose for our immune system. Exercise has a profound impact on our bodies – almost every cell in our body is affected during and after exercise (1). Exercise works, we’re just not completely sure how!

Long-term effects of exercise

We’ve known for a while that lifelong activity and exercise is a crucial way to reduce the risk of many diseases such as cancer, heart conditions and other chronic conditions (2). However, there is increasing evidence showing that keeping an active lifestyle lowers chances of contracting a range of infectious diseases such as bacterial and viral infections (3).

This study (4) showed that adults over 60 years who were active undertaking vigorous exercise upwards of three times a week showed significantly higher immune system responses to a vaccine than a sedentary group of the same age. Suggesting that consistency of exercise, throughout our lifetime, is key in looking after our immune system.

Age related decline of our immune system is a natural process where detection of disease, clean up and protection from further disease all slow down; it’s inevitable – right? Well, it’s been shown that active individuals over 60 that have kept consistent throughout their lifetime, slow and negate some of the aging processes of our immune system (5).

Short-Term effects of exercise

Whilst long-term benefits of regular physical activity have been shown, the effect of a single session of exercise is still disputed (6).  Many say that high intensity and volume of exercise can be detrimental to your immune system in the short– term, making your body at higher risk of contracting an infectious disease (7). Perhaps this adds to the notion that too much of anything can be a bad thing?

However, others have investigated the immune systems of elite athletes and show that over the course of a year of following intense training of ultra-marathon runners, showed an average report of sickness days of 1.5 days versus the US average of 4.4 (8). This may contradict the notion that high intensity or volume of exercise is detrimental – as the highest level of athletes with the highest intensity and volume of exercise, show less risk of sickness than the average person.

Maybe the question we should be asking is does a level of exercise that we are not prepared for, have detrimental effects to our immune system?

Conclusion

We have briefly touched on the long-term effects of exercise and the surrounding debate around the short-term effects. Exercise has a profound effect on our immune systems. The benefits of exercise have clearly been highlighted, but how this happens we still don’t fully know!

In these troubling times its important to look after yourself and that means keeping active. Be kind, stay at home and wash your hands!

Thanks for Reading.

Aran Pemberton

Aran qualified as a Physiotherapist graduating from the University of Worcester in 2017. He has since been working within the NHS, rotating into different specialities such as the Emergency Department, Critical Care, Orthopaedics and MSK.  He has worked with people of all ages and different levels of health and fitness, encouraging exercise as an essential part of health and wellbeing and providing the best care for his patients.

Aran has a keen interest in soft tissue mobilisation and movement re-education as part of the rehabilitation process. He has an interest in sports injuries and has experience treating players and working with the strength and conditioning coaches under the physio in Worcester County Cricket Club.

References

1. Kostka T, Berthouze SE, Lacour J, Bonnefoy M. The symptomatology of upper respiratory tract infections and exercise in elderly people. Med Sci Sports Exerc (2000) 32(1):46–51. doi:10.1097/00005768-200001000-00008

2. Warburton DER, Bredin SSD. Health benefits of physical activity: a systematic review of current systematic reviews. Curr Opin Cardiol (2017) 32(5):541–56. doi:10.1097/HCO.0000000000000437

3. Pape K, Ryttergaard L, Rotevatn TA, Nielsen BJ, Torp-Pedersen C, Overgaard C, et al. Leisure-time physical activity and the risk of suspected bacterial infections. Med Sci Sports Exerc (2016) 48(9):1737–44. doi:10.1249/MSS.0000000000000953

4. Kohut ML, Arntson BA, Lee W, Rozeboom K, Yoon KJ, Cunnick JE, et al. Moderate exercise improves antibody response to influenza immunization in older adults. Vaccine (2004) 22(17–18):2298–306. doi:10.1016/j.vaccine.2003.11.023

5. Campbell, John P., and James E. Turner. “Debunking The Myth Of Exercise-Induced Immune Suppression: Redefining The Impact Of Exercise On Immunological Health Across The Lifespan”. Frontiers In Immunology, vol 9, (2018). Frontiers Media SA, doi:10.3389/fimmu.2018.00648.

6. Walsh NP, Gleeson M, Shephard RJ, Gleeson M, Woods JA, Bishop NC, et al. Position statement. Part one: immune function and exercise. Exerc Immunol Rev (2011) 17:6–63.

7. Nieman DC, Johanssen LM, Lee JW, Arabatzis K. Infectious episodes in runners before and after the Los Angeles Marathon. J Sports Med Phys Fitness (1990) 30(3):316–28.

8. Martensson S, Nordebo K, Malm C. High training volumes are associated with a low number of self-reported sick days in elite endurance athletes. J Sports Sci Med (2014) 13(4):929–33.