The Benefits of Exercise On Your Immune System
As a nutritional therapist and food enthusiast I’ve always been focused on nutrition as the foundation of health, but when I quit my job to focus on healing and finishing my studies, I noticed the huge impact that lifestyle had on my health, particularly sleep, movement and stress reduction.
We’ve all heard that exercise is good for us and some prioritise it over nutrition but here’s a few details that may help you understand what’s going on and why we should keep it a priority along with sleep, low stress and good nutrition.
Getting moving is great for our bodies and moving outdoors regularly is one of the cheapest and easiest ways to improve our health overall. The benefits are almost endless. It’s not just good for our muscles, bones, cardiovascular health and insulin resistance but it also has an impact on our mood, cognitive health and coordination. It can reduce the incidence of many chronic diseases and therefore exercise can also have a profound effect on our immune system, not only by reducing the impact of viral and bacterial infections but also by lowering key markers of inflammation. The structure of our body and it’s importance is becoming more appreciated in nutrition and when you think that a good structure enables appropriate transport and delivery of nutrients, hormones, neurotransmitters and immune cells it begins to make sense why.
So after the crazy year that we’ve had, let’s dig a little deeper into its impact on the immune system. It is not a system that simply switches ‘on’ or ‘off’ and it is not a case of simply needing to ‘boost’ it with nutrients and supplements. It is responsive to our actions and our environment. It can detect and adapt to changes in our metabolism, nutrition and movement and informs the behaviour of the many different cell types.
Our immune system is a complex, highly organised network of cells and molecules spread throughout our body and has an integral role in all physiological processes, even reproduction, and exercise supports the immune system’s ability to carry out its many tasks.
When the immune system mounts an inflammatory response, it needs to switch back into a regulatory state to prevent an excessive attack or damage and physical activity leads to an elevation in T-regulatory cells (a subset of immune cells that modulate the immune system). In fact, the incidence of autoimmune disease is higher in people less engaged with physical activity.
Exercise can benefit the Lymphatic system (an integral part of the immune system), critical in autoimmune disease but important in general health as well. When it comes to circulation, we tend to focus on blood flow and the lymphatic system is often forgotten. The movement of lymph is governed by our rhythmic daily muscle movements and it propels the lymphatic fluid around our body so it can patrol for infections or anything suspicious. It doesn’t have a pump like the heart, so if the flow of lymph stops or becomes impaired, this vital immune surveillance and defence function can also become compromised.
The immune system can be triggered and develop inappropriate regulation (too much or too little) and can lead to silent inflammation. But this low grade chronic inflammation can be attenuated with regular, moderate exercise. In fact regular bursts of movement over the last two thousand years have been a part of our evolution by inducing an anti-inflammatory effect, cleansing us of any lingering inflammation. Lots of research is now informing the medical direction of exercise therapy to reduce chronic inflammation in obesity, diabetes and cardiovascular disease etc. It is also important in cancer, depression and Alzheimers. While a sedentary lifestyle is a short-cut to low immune function, too much exercise can also be detrimental.
Exercise does in the short term induce an inflammatory response, because it does ultimately constitute a physiological stress on the body. This is a good form of stress and necessary to make any tangible progress from a workout. However, if the duration of vigorous exercise exceeds 90 minutes then some research suggests that while immune cells venture into peripheral tissue for repair, this can leave the body an open window to infection. Other research suggests that this actually heightens immune surveillance, but more research is needed. So duration, intensity and frequency matters. Nutritional status can exacerbate exercise-induced stress as well but this is better addressed through the diet rather than supplementation. The only exception to this rule is vitamin D. Make sure that you fully recover from your workout before working out again, as these spikes in inflammation can begin to overlap. Your ability to repair and recover is in part due to your genetics, so it’s important to listen to your own body and make prudent choices about your recovery.
Our white fat tissue is immunologically active and packed full of regulatory immune cells, which help turn down inflammation. Too much white fat obviously tips the balance as more is not always better. However, losing too much weight can pose a risk to losing that immunological protection from infection. So maintaining a balance is key and a healthy body weight can be of use in infection fighting potential.
From the age of 20, our thymus gland begins to shrink and with it goes the number of white blood cells it stores. It is where your army of immune cells are trained and given their specific role. It was discovered recently that muscle cells release a molecular messenger that helps prevent thymus shrinkage. Therefore helping us maintain a healthy number of T-lymphocytes. Before you despair, it is never too late to benefit from regular exercise.
Lastly our gut microbiome also benefits from exercise. Our gut bugs need us to do exercise and particularly benefit from us walking uphill. On the other hand too much exercise can induce a leaky gut, causing unwanted particles to enter the bloodstream triggering an immune response. Poor digestion and an imbalanced microbiome can impact the lymphatic system which intimately supports nutrient absorption and fluid balance (particularly essential fats and fat soluble nutrients such as vitamins A, D, E, K). But keeping well hydrated, avoiding too much salt, eating a high plant-based prebiotic diet as well as not over-doing your training can help the gut and lymphatic system stay healthy.
There’s just so much to this topic, it’s impossible to cover it all at once. But I hope this gives you a little insight into the power of movement and its importance in avoiding chronic health issues.
This article was inspired by facts previously published on Dr Jenna Macciochi's website