Taekwondo is a weight segmented combat sport, and the reduction of body mass is considered an important aspect in order to gain advantages over opponents in terms of limb length and power to mass ratio .
There are numerous associated negative effects on both health and performance from reducing body mass. Chronic periods of calorie restriction which induce losses of body fat and muscle tissue can lead to a whole host of issues including those on immune function, bone structure and menstrual function in females . This can also lead to eating related disorders including anorexia nervosa  whilst negatively effecting performance by not having enough available energy to compete despite a period of refeeding.
Dehydration (caused by exercise, saunas, diuretics etc.) can display negative effects through losses of as little as 2% of body mass which can decrease cognitive function , with losses of over 5% body mass effecting cardiovascular, liver and kidney function potentially leading to cardiac events and renal failure . It should be noted that there have been associated deaths in combat sports over recent years and very recently in Taekwondo . Were this to occur under a coaches supervision they may be legally culpable and this could lead to criminal prosecution.
Given the dangers associated with varying methods of reducing body mass in all instances student athletes should seek professional guidance from either a registered dietician or SENr registered sport nutritionist where possible. Coaches and athletes are highly encouraged to attend our S&C for Taekwondo Athletes Course which includes an athlete nutrition and weight-making module, where guidance is provided by our course leader Carl Langan-Evans, a researcher in the field of safe and effective body mass loss for combat sport athletes .
In all cases we recommend coaches and athletes adopt an evidence based approach, monitor their athletes’ weight over time and plan for competition well in advance. Penalty fees for weight division changes are in place at Student National Championships Series events to encourage forward planning and discourage incautious weight division entries. It is our desire that club committees and contracted coaches improve weight monitoring and selection such that no division changes at weigh-in need occur.
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