Title: Bodyweight Manipulation in Boxing

Key words: Weight loss, dehydration, starvation, fluid restriction

Date: July 2000

Category: 12. Sports

Type: Article

Author: Dr M Draper

  Bodyweight Manipulation in Boxing



There are 12 weight divisions in boxing varying by 3kg at lower weights (Light fly to Light ) and increasing to 10 kg from Heavy to Super Heavy. The current coaching philosophy is to enter the lowest weight category possible without impairing performance or health. The degrees to which weight manipulaton methods will be employed depends on the type of tournament and the number of contests needed to achieve success. In a 'dual' match, such as the UK versus USA, the boxer only has a single weigh-in and competes once. However, in Multi-nation (i.e. the Olympic games ) the boxer must weigh-in before each contest. In the 1988 Seoul Olympic games, 441 boxers entered and 5 boxers made the weight 7 times for 6 contests.

Methods employed to manipulate bodyweight

The final 0.5-1.0 kgms of weight loss are the most difficult. Unethical or illegal methods have been used to achieve this, such as laxatives , diuretics and blood transfusions (autologous before and after weigh-in). This paper, however, is focused on the 'normal' methods.

Dehydration and starvation In a study (cited by Dr Marcus Smith ) which looked at the weight loss methods employed by senior England International boxers ( n=73) the passive methods that were most popular were fluid and energy restriction. However 21.9 % used saunas to enhance their fluid loss. This could have effects on their electrolyte balance, as could diuretics (1).

With respect to fluid restriction, 21 days before competition 4.1% had started this method (at 7days 68.5 % and 3 days 93.2%). On the day before weigh-in, this rose to 95.9% which meant that only 2 boxers had not restricted their fluid intake. The consequences of this could be to reduce extra cellular fluid spaces and, in particular, the cerebrospinal fluid volume. This would mean an increased potential for minor or major cerebral damage resulting from blows to the head. The discussion continues into the long term consequences with regard to cerebral damage. A recent retrospective study in Sweden (2) on amateur boxers failed to show any signs of chronic brain damage. There are studies that have looked at brain scan results to defend the continuation of boxing. However, just as with osteoarthritis in footballers, the obvious conclusion arrived at by those who care for the 'injured sportsman' is that there is an increased element of risk. Methods that might increase that risk, such as dehydration or hypohydration, should be avoided.

Energy restriction was employed by 20.5% of the 73 boxers 21 days before the weigh-in and this increased (Day 7: 89% , Day3 : 97.3%) to 100% one day before the weigh-in. The loss of glycogen from the liver and muscle helps to achieve weight loss because glycogen is usually well hydrated (1gm glycogen has 12 gms of water). However, the loss of glycogen in endurance athletes leads to early fatigue (3) and 'dead at the weight'.


Measures employed to stop boxers entering the ring dehydrated, such as a longer interval between the weigh-in and the fight have lead to a reduction in fatalities (4). Paradoxically, this has meant more time to replete glycogen stores after measured weight reduction and guidelines exist depending on the interval between weigh-in and the fight (5). It would appear that new methods need to be employed to ensure that a boxer doesn't fight when dehydrated (e.g. urine osmolality and/or blood haematocrit measurements) and that to avoid drastic manipulations in weight (which may have metabolic and health consequences (6) boxers should only be weighed just before they get in the ring.

Bodyweight manipulation References
  1. Caldwell JE et al. 'Differential effects of sauna-, diuretic-, and exercise induced hypohydration.' J. Applied Physiology 1984; 57:4 , 1018-1023.
  2. Haglund Y et al. 'Does Swedish amateur boxing lead to chronic brain damage?' Acta Neurol. Scand. 1990; Oct,82:4,245-52.
  3. Holloszy JO and Kohrt WM 'Regulation of carbohydate and fat metabolism during and after exercise' Ann. Rev Nutr., 1996; 16: 121-38.
  4. Ryan AJ 'Intracranial injuries resulting from boxing' Clin. Sports Med, 1998; Jan , 17:1, 155-168
  5. Fogelholm M 'Effects of bodyweight reduction on sports performance' Sports Med. 1994; Oct , 18:4, 249-67.
  6. Brownell KD et al. 'Weight regulation practices in athletes: analysis of metabolic and health effects' Med. Sci. Sports Exerc., 1987; Dec , 19:6, 546-56.