Assistant professor for nutritional sciences with focus on health promotion / everyday culture and health at the institute of health sciences, department of nutrition, consumption and fashion at the University of Education Schwäbisch Gmünd, Germany.
Member of the German work group "Nutritional counselling at the German Olympic Sports Centres" (since 2009).
In some sports the body mass is either restricted to given categories due to the rules of the discipline (i.e. weight class sports such as combat sports) or a low body mass is regarded as the cutting edge to be successful (i.e. ski jumping, gymnastics).
Especially in weight class sports, the habitual body mass during the training process is often considerably higher (approx. 5-10%) than the maximum allowed body mass in the given weight class (Degoutte 2006).
Athletes in weight class sports often reduce their body mass rapidly before competitions. The magnitude of weight loss varies between 2 - 10% of body mass and may even be higher, with a high percentage of competitors reducing body mass by 5-10 % in 3-4 days before competition (Aldermann 2004, Artioli 2010).
The effects of repeated and rapid weight loss on performance outcomes during competitions are still equivocal and seem to depend on the methods used to reduce body weight, the magnitude of weight loss, the duration of the restoration period after weigh-in and the pattern of fluid and food intake in this period (Slater 2014, Mendes 2013). In contrast, the adverse effects of rapid weight loss on health status are well documented and include physiological (e.g. dehydration, electrolytic disturbances, impaired thermoregulation, muscle glycogen depletion) and psychological (e.g. decreased vigor, concentration, self-esteem and increased confusion, fatigue, depression) issues (Franchini 2012). In extreme cases, rapid weight loss was responsible for the deaths of athletes (Center of disease control and prevention, 1998).
Thus, the sports nutritionist is in a dilemma to balance the individual health risks versus the approach to support the athlete to reach his or her individual body mass and sportive goals. Besides recent discussions to adapt the rules and to improve educational programmes for coaches and athletes, other factors may need to gain greater emphasis during counselling. For instance, gradual instead of rapid weight loss (0,7% of body mass/week), avoiding dehydration and low-carbohydrate diets, as well as discouraging athletes to use harmful weight loss methods (use of sauna, fluid restriction, fasting, vomiting, use of diet pills, diuretics (banned by WADA) or laxatives). The presentation will include a case report and give insight into nutritional counselling of weight-class athletes before and after the weigh-in.