The human body has been designed to protect itself against foreign invaders (bacteria, viruses, etc), all the mechanisms used for defence are known as immune system. Exercise and nutrition can impact the function of your immune system, so at this time of year when the flu and the common cold are running rampant through the workplace it is important to know how exercise and nutrition can impact your body’s health.
The immune system is made up of two lines of defence. The first is called the Innate Immune system, consisting of natural barriers. There are three natural barricades: physical barriers, such as the skin and epithelial tissues of the lungs, nose and intestinal tract; chemical barriers, such as the high acidity of the stomach; and cellular barriers, such as phagocytic cells whose job are to engulf invaders. The innate immune system is non-specific and will attack and destroy anything that is foreign to the body. The second line of defence is the acquired immune system which is called into action if the first barricades are breached and infection occurs. The acquired immune system is constantly adapting to new and specific invaders. When phagocytes (from the innate immunity) fail to destroy intruders they bring the bacteria or microbials to a specific cell called a lymphocyte. Lymphocytes identify the foreign impostor and then tell other immunity cells to seek out and destroy the attacker. The lymphocytes have an amazing memory function which helps them to recognise and remember the foreign invader and launch an attack if reinfestation occurs in future.
This basic and brief outline of how our immunity works shows you that our defences are quite complex, with many mechanisms. While it is difficult to accurately assess the impact of nutrition and exercise on immunity there is some evidence to support the need for a healthy well-balanced diet with moderate exercise.
Exercise and Its Impact on Immunity
It has long been understood that prolonged and intense exercise can lead to immune dysfunction increasing the risk of infection, especially upper respiratory tract infections. Stress hormones, such as adrenalin and cortisol which are produced during strenuous exercise and weight training are associated with a suppressed immune cell function. While this is mainly an issue for athletes it is important to note that it may impact yourself also, especially if you experience low-immunity levels. Keep in mind that you do not get results from a workout itself, but from the recovery afterwards. If you do 5 to 7 sessions a week you are probably doing too much and it could have an impact on your immunity function. Doing 3 to 4 sessions per week is an adequate amount; it will give you time to recover, allowing stress hormone levels to drop and immunity strength to increase.
Nutrition and Its impact on Immunity
Inappropriate nutrition can compound the negative influence of heavy training on immunity, decreasing defences and increasing risk of infection. Maintaining an effective immune system can be achieved by avoiding deficiencies in nutrients which play a key role in innate and acquired defences.
Dietary protein is crucial for rapid cell production and the production of proteins for important biological activities used within the mechanisms of innate and acquired immunity. Inadequate intake of protein has been linked to immunity dysfunction.
It has been long understood that deficiencies in specific vitamins and minerals such as iron, zinc, vitamin A and E, B6, and B12 are associated with immune dysfunction, as are magnesium, manganese, selenium, and copper. Inadequate levels of Vitamin C will also cause a depression in the immune defences. Consuming enough Vitamin C (1000-1200mg/day) is known to have a protective effect on immunity. Vitamin and mineral supplementation is a good way to avoid deficiencies and therefore prevent immunosupression; however it is important to note that excessive amounts of some nutrients can negatively affect immune function therefore it is not worth taking supplements in mega doses.
Carbohydrates have been found to reduce stress hormone levels in the body and therefore decrease the risk of immune dysfunction. Low carbohydrate diets (coupled with excessive amounts of exercise) can put one at risk of the immunosuppressant effects of cortisol and adrenalin. While low-carb diets are in vogue they are not healthy as the human body naturally needs carbohydrates to survive. It is better to decrease overall daily energy intake (or calorie intake) rather than reducing carbohydrates specifically.
Fluid consumption maintains healthy immune function as it assists in avoiding dehydration which has been linked with an increase in stress hormone response. Fluid intake during exercise maintains saliva flow; saliva contains anti-microbial properties which help in destroying foreign invaders as they enter the body. Studies have shown that lemon flavoured carbohydrate containing drinks are best for maintaining salvia flow during exercise.
If you suffer from colds and flues throughout the winter months (or all year round) it might be helpful to look at your nutrition and exercise routine. Positive changes to these areas can encourage a strong and health immune system. If you would like any help in this area please come and chat to one of our expert team at Pro-Fit Health Club.