Performance and Nutrition
Coach Dave Lett
MA, MS, CPT, TASAC-F, SAQ
April 2, 2023
A definition of malnutrition
What is malnutrition and how is it defined? It can be defined as a state of nutrition where a deficiency or excess (or imbalance) of energy, protein and other nutrients resulting in measurable adverse effects on tissue/body form (body shape, size, composition), body function and clinical outcome (Soeters et al., 2017). When looking at the clinical definition for diagnostic criteria for malnutrition, the definition changes to a clinical view. The clinical definition of malnutrition is a subacute or chronic state of nutrition, the combination of varying degrees of under- or over-nutrition and inflammatory activity has led to changes in body composition and diminished function (Soeters et al., 2017). Malnutrition can be broken down into three sections: not enough to eat in general; not eating the proper things (nutrients); and not being able to properly digest and absorb the needed nutrients. The types of malnutrition would include under-nourished, or too little food/lack of nutrients and over-nourished, or too much food/unbalanced nutrients.
The effects of over-eating on sports performance and participation
Over-eating can be labeled as the excess of food that is consumed in relation to the amount of energy that is expended. Overeating can lead to excess weight gain and increased the possibility of becoming overweight/increased BMI – body mass index (height/weight). This can then affect the athletes’ confidence and motivation to train. Training is approximately 50% mental focus, 25% preparation and 25% execution. When an athletes’ confidence is effected, it lowers self-esteem and morale decreases, also increasing anxiety and worry (psychological effects). Eating habits can go from one extreme to another, from health eating, to overeating, to clinical eating disorders (Jeukendrup & Gleeson, 2009). With excess weight gain athletes may find difficulty in exercising (running, jumping, twisting) due to stress and strain placed on joints and the weight-bearing areas (knees, hips, lower back joint). Most importantly there is an increased risked for illness (hypertension, diabetes). Which can lead to stroke, heart disease, kidney disease, and many other medical complications.
The effects of under-eating on sports performance and participation
When someone is under eating they are consuming lower calories than needed for the body to properly function. In 2014 the International Olympic Committee created a new term called Relative Energy Deficiency in Sports (RED-S) (NSCA, 2020). RED-S can also be directly connected to the term known as Low Energy Availability (LEA) (NSCA, 2020). Potential LEA effects on performance include: Decreased endurance performance, Decreased muscle strength, Decreased glycogen stores, Depression, Irritability, Decreased Concentration, Decreased training response, and increased risk of injury (NSCA, 2020). Other things to consider are rapid weight loss and loss of lean muscle mass.
The effects of dehydration on sports performance and participation
Dehydration can be defined when the amount of fluid in the body lost is more than it consumes (sweating). Some of the common signs and symptoms are feeling thirsty, tired, dizzy and lightheaded. The risk of dehydration is greater in severe warm climates, which can result in heat injuries (heat stroke). Athletes exercising in high altitudes are likely to lose fluid beyond just exercise (NSCA, 2020). Some other sings are dark colored urine (as well as increased times you urinate), rapid heartbeat or breathing rate, and hallucinations. There are two types of dehydration. The first is extracellular dehydration, most commonly the result of diuretics and not from exercise. The second is intracellular dehydration, which is the loss of hypo-osmotic fluid that creates an osmotic gradient, causing water to move from the intracellular fluid to extracellular fluid (NSCA, 2020). This type of dehydration results from normal urinary losses and low fluid intake during exercise (NSCA, 2020).
Performance effects: blood flow is reduced to muscles, less oxygen and therefore fatigue happens quickly. Athletes loses the ability to sweat, which increases body temperature and therefore means a loss of concentration/focus. An increased chance of injury and severe muscle cramping may happen because of low salt concentration.
References
Jeukendrup, A., & Gleeson, M. (2009). Sport Nutrition – 2nd Edition (2nd ed.). Human Kinetics.
NSCA’s Guide to Sport and Exercise Nutrition (Second). (2020). NSCA’s Guide to Sport and Exercise Nutrition (Second). Human Kinetics.
Soeters, P., Bozzetti, F., Cynober, L., Forbes, A., Shenkin, A., & Sobotka, L. (2017). Defining malnutrition: A plea to rethink. Clinical Nutrition, 36(3), 896–901. https://doi.org/10.1016/j.clnu.2016.09.032
