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OVERTRAINING- may compromise your immune system

We are all trying to adapt to a new way of living with COVID-19. The 21st century has catapulted us into the face of viral threat and we are inundated with information about our immune system.

Whether you love exercise or not, most people already know that regular exercise is an essential component of health and well-being.

But, what happens when a regular, moderate routine becomes something bordering on obsessive behaviour?

A typical weekend warrior or gym-goer who manages to fit in 3-5 workouts per week, may now find themselves confined to 'lockdown' restrictions with anxiety issues and time on their hands.

So many online programmes to choose from, and the delivery of shiny new home equipment, may result in exercise-induced injuries or the outcome of long-duration, or high-intensity overtraining without the necessary physical adaptations.

Injuries are common when there is no hawk-eyed trainer or coach to maintain strict form. and going from zero to hero due to boredom, may bring on other issues.

Overtraining syndrome (OS) is more likely to affect endurance athletes, and elite athletes are no strangers to upper respiratory tract infections (URTI's) Of course, the principles of training require an overload, but this is usually performed gradually, not within the first 10 days of social distancing!

At what point does training hard, become OS?

This brings me to the immune system in relation to exercise.

Regular, moderate intensity exercise supports immune function and is an important aspect in reducing inflammation as the underlying cause of many chronic diseases. However, as the curve in exercise intensity and duration gets steeper, the optimal amount of exercise suddenly changes and an upset in the delicate balance results in an unwanted immune response. At a certain point optimal training can become over-reaching, which in turn can become over-training.

Elite athletes or individuals pushing themselves to the limit and beyond, place a huge stress on their immune systems and may leave themselves vulnerable to foreign microorganisms. Under normal, well-nourished circumstances, our body's built-in defence system works well at coping with a stream of constant activity. However, the additional demands of hard-working skeletal muscle and cardiovascular muscles places an extra load on the immune system and there is a higher demand for nutrients.

Rewarding yourself with a pizza and beer after a mega-workout does not help with re-supplying some antioxidant nutrients and high quality protein and carbohydrates.

On the other side of the spectrum, highly restrictive eating patterns and undersupply of nutrients (carbohydrates, protein, vitamins, minerals, antioxidants) sleep deprivation or inadequate rest between workouts, can upset the immune system as well. Elite athletes and female ballet dancers, have been found to be at risk for stress fractures and respiratory infections when their nutrient intake was inadequate.

COVID-19 has put an end to many elite and everyday sporting events and goals. The stress of confinement and the total upheaval of everyday routines, adds another stressor to our immune systems.

Emotional stress has impacted all of us in varying degrees. Biologically, the emotional stress on the brain, heart, muscles and gut, have far-reaching effects on exercise performance and recovery.

The difference between over-reaching and over-training is the amount of time it takes to recover. Signs such as mood swings, ongoing muscle soreness and an increase in fatigue or decrease in strength should all be taken into consideration, Those 'heavy' legs at the start may also be clues to over-trained and under-recovered muscles. An additional marker is an increased resting heart rate. Many coaches will check for a higher than usual morning heart rate as a marker of over-training.

Immunosuppression from over-training is something most people are trying to avoid now. Remember, you do not have to be a well-conditioned elite athlete to experience OS.


LEUCOCYTES- Leucocytes are circulating white blood cells that protect the body and fight foreign or invading substances.

IgA -Lower levels of Salivary Immunoglobulin A (IgA) have been correlated with increased susceptibility to URTI's (upper respiratory tract infections). Secretory IgA is an antibody found in the mucous membranes and plays a crucial role in the immune system. In the gut, IgA is found in the intestinal lumen, protecting the intestinal epithelium from invading pathogens by not allowing them to adhere to the surface. Glutamine has been shown to enhance sIgA function.

CD4-T cells + CD8-T cells - CD4 proteins help to trigger the body's response into action(gather the troops) against invaders. CD8 cells are 'killer' cells and produce antibodies that help fight off the invading species. after prolonged or very strenuous exercise, the levels of these white cells may decrease and the production of antibodies may be limited for a while. This weakened immune defence may lead athletes to being 'open' to infection, particularly if their recovery strategy is not optimal.

CORTISOL - Cortisol is a steroid hormone that multi-tasks on many levels. One of its functions(along with epinephrine) is to alert the body to danger or stress and activates the 'fight flight' survival mechanism. Constant stress as well as repeated bouts of heavy training or long hours of training can result in a chronically elevated level of cortisol and depleted adrenal function. Cortisol functions to reduce inflammation in the body but this chronic activation may cause immunosuppression by not allowing the immune system to fully recover.

GLUTAMINE - L-Glutamine is the most abundant amino acid in the body and a large number of cells and tissue require glutamine in order to function. Low levels of plasma glutamine have been detected in over-trained athletes and inflammatory proteins (TNFa and IL-6) are upregulated due to the high demand for glutamine. Chronic inflammation places a huge load on the immune system and may result in infection or disease. Glutamine supports muscle tissue and growth and can be used as part of an athletes recovery strategy.


*Exercise within your ability and experience

*Supplement (not overdose) with L-Glutamine, especially if you are vegan.

*Make use of protein recovery drinks. NB this does NOT ONLY APPLY TO MEN!!

*Increase your intake of leafy greens and brightly coloured high-antioxidant content fruit and veg.

* Make sure you are eating enough healthy fats and omega 3 fatty acids found in avocado, olive oil, fish, nuts and seeds.

*Ensure you have 7-9 hours of sleep per night.

*Test your 25-OH Vitamin D. Deficiency in vitamin D is associated with increased autoimmunity and risk for infection due to its affect on the innate immune system.

Vitamin D is necessary for many essential functions in the human body, the most recognised being bone maintenance and soft tissue repair. Variations in Vitamin D receptor genes (VDR) may leave certain individuals at risk for vitamin D deficiency or insufficiency.

Vitamin D also assists with reducing inflammation by activating ant-inflammatory cytokines (chemical messengers) and reducing inflammatory cytokines such as IL-1, IL-6 and TNFa. (Cynthia Aranow, MD Invesigator. J Investig MED 2011)

*Evidence has shown that prolonged and chronic intensive exercise can suppress the immune system especially when combines with mild hypoglycaemia (not enough carbs).The resulting drop in plasma glutamine can leave the athlete open to a state of immunosuppression.

R. Costa et al. have shown that providing consistent carbohydrates throughout training and maintaining stable blood glucose levels, cortisol release was reduced and salivary IgA was increased, thereby decreasing the risk of over-training,, immunosuppression and reduced the amounts of URTI's.

Train wisely, eat well and make the most of this transition through through strange times.



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