Combat sports are often categorised as “weight class” sports, where weight classes are devised so that athletes of a similar size are matched against similar competitors to create an equal playing level and reduce the advantages for the larger opponent (1).
However, often competitors will reduce their weight acutely by various means in attempts to gain an advantage over their opponent (2), and in no sports is this behaviour more apparent than in combat sports (e.g. wrestling, boxing, judo and MMA).
In fact, in combat sports, pre-competition acute weight loss by “any means necessary” is steeped within the culture and considered an essential part of the sport (3).
Is Weight Cutting A Problem?
Unfortunately, research suggests that pressure placed on weight class sport athletes to reduce weight significantly prior to competition can develop a culture of disordered eating (unusual food behaviours), and a greater risk of clinical eating disorders (4-6).
In weight-sensitive sports, extreme weight control measures prior to competition have been seen in 94% of elite athletes (7).
In combat sports specifically, studies in wrestlers show a high incidence of acute rapid body water loss and dehydration through the use of sweat suits, excessive exercise and extreme heat environments (e.g. sauna) (8-10). This behaviour has also been seen in mixed martial arts where 39% of athletes were seen to be competing in a dehydrated state (1).
The consequences of acute rapid weight loss through extreme dehydration include not only negative physiological changes to your muscle contraction and central nervous system; not only impaired performance during competition; and not only excessive cardiovascular strain. Ultimately, these extreme behaviours can tragically cause death (1, 8, 11).
Cutting Weight | The Prep
Pre-competition weight management must be comprehensively and strategically planned. Assessment of physiological variables such as body fat percentage and lean body mass, must be collected alongside bone density assessment values (12-15).
Athlete evaluation should consider not only food and water consumption levels, but also any history or signs of eating behaviours to assess for the likelihood of disorder eating (2).
How To Cut Weight Safely & Effectively
Effective and safe acute weight loss strategies should only be performed when the athlete and coaching team are aware and knowledgeable around best practices for nutrition and weight management in athletes. This would include understanding the complex nature between exercise, nutrition, energy availability and negative effects of extreme dietary behaviours (16-17).
This is particularly important in female athletes where the female athletic triad of disordered eating, amenorrhea and osteopenia must be considered, and evidence suggests even 52% of doctors and 57% of physiotherapists cannot recognise the signs (18).
As such combat sports athletes should be guided in any weight loss programmes by a healthcare professional with sufficient experience and knowledge, which can reduce the risk of disordered eating whilst successfully reducing weight for competition (7).
Any dietary weight loss plan should (if possible) be guided by physiological examination including blood and urine markers to assess for nutrient deficiencies.
If deficiencies are highlighted appropriate supplementation should be prescribed to regain normal levels.
Daily meal plans should approximately consist of:
1.5-2g/ kg of protein, 3-5g/ kg of carbohydrate &15-20% of total energy intake from fat (2).
Calorie intake for females should be sustained at 30-45 kcal/ kg per day with a gradual weight loss of 0.5kg per week to avoid menstrual irregularities (2).
To sustain a gradual weight loss of 0.5kg per week approximately 500 kcal per day should be lost through exercise and activity (2).
Ultimately, weight loss should be guided by a balance of energy expenditure during training, energy (calorie) consumption via food and the supplementation of appropriate nutrients to sustain physiological health.
Carb intake can be reduced (but not removed!) and balanced around the intensity and duration of activity planned for each specific training session (19).
Protein consumption should then be increased to prevent lean muscle loss as the exercise is fuelled more and more by amino acid oxidation (19). Approximately 2-2.5g/ kg of protein should be enough to sustain lean mass (19).
Such nutritional programmes should aim for the athlete to commence a training camp prior to competition at no more than 5-6kg above the weight at which he/ she will be competing (19).
The acute loss of weight through intentional dehydration (as mentioned) should be minimised. However, due to the cultural requirement for this practice to continue specific guidelines should be followed.
✓ Body fat should remain at or above 5% for males and 12% for females (7, 20).
✓ Athletes should not try to lose more than 2% of bodyweight rapidly before weigh ins and should not increase beyond 3% above competition weight after weigh ins (2).
✓ Duration of time between the weigh in and competition should be considered. For example, in MMA this tends to be 24 hours prior to the fight, in other sports such as wrestling, judo and Taekwondo this may be 2-3 hours.
✓ Approximate amounts of 1-1.5kg of acute weight loss via intentional dehydration have been seen in combat sports athletes without performance impairment or signs of ill health (19).
Sadly in most combat sports weight loss of 3-4kg in the week prior to competition is common, which has been seen in wrestling (21-22), Taekwondo (23), judo (24) and boxing (25). Such degrees of acute weight loss are sufficient to significantly reduce sporting performance characteristics including punching force (26).
After The Cut
It is essential for the athlete to be monitored on a regular basis following the peak of the acute weight loss (2).
The athlete should be advised to consume fluids which incorporate carbohydrates and electrolytes, as well as creatine if the time between weigh in and competition is substantial (27). Water alone can be consumed, however drinking just water may reduce the drive to drink and may increase urine output. This can be attenuated by including salt in your rehydration beverages (28). This practice must be overseen by a nutritionist or clinician with experience and knowledge in this area!
✓ The amount of fluid consumed should be equal to 150% of weight loss through sweat during the cut (29).
✓ Inclusion of salt and carbohydrates in the fluid will ensure the body retains enough fluid, will improve intestinal absorption of water and will replace glycogen stores in the muscle (29-30).
✓ The use of intravenous (IV) fluid replacement after the weigh in should not be recommended unless a serious health issue demands it.
IV rehydration is no more efficient than oral rehydration (31-32), but also it is banned by the World Anti-doping Agency (WADA) Code under the WADA Prohibited List, section M2. This has also led for the USA anti-doping agency to ban its use in the Ultimate Fighting Championship (the premier MMA- and combat sports organisation outside of professional boxing) (33).
>>> Red Flags
During or following acute weight loss procedures specific issues can be used as identifiers for an athlete or coach to seek medical assistance. Such athletes should immediately be considered for removal from competition.
1) The reduction of body mass index and body fat percentage below the following figures and presentation of the stated symptoms:
MALES: BMI <18.5%, Body Fat <5%, low testosterone levels
FEMALES: BMI <18.5%, Body Fat <12%, primary or secondary amenorrhoea
2) Amenorrhoea for longer than 6 months (or beyond 3 months if < 18 years old)
3) Evidence of low bone density
4) Athletes who are uncooperative or show lack of responsiveness to weight loss measures
5) Athletes who are affecting other team members through negative eating behaviours or unstable mood
6) Athletes unable to sustain a positive energy balance over the pre-competition period, or show lack of responsiveness to training and increased fatigue levels.
7) Athletes who demonstrate with signs and symptoms of clinical eating disorders (e.g. anorexia or bulimia)
8) Athletes with serious physical complications (e.g. cardiac dysrhyrthmia, major limb swelling, fainting.
Modified from (2).
Specific physiological complications from acute weight loss strategies prior to competition can be cumulative during the career of a combat sports athletes.
They can include long term nutritional deficiencies (e.g. anaemia) but also may result in chronic fatigue, reduction in immune system function, stress and depression; as well as issues medically in the gastrointestinal, cardiovascular, endrocrine and reproductive systems (34-35).
Irregular menstrual dysfunction and low bone density in females is also associated with greater risk of musculoskeletal injury (36).
As such this re-affirms the risks of weight cutting on the bodies of combat sports athletes.
Take Home Message
Obviously, whilst an “accepted” and commonly seen part of combat sports, weight cutting through extreme dietary changes and dehydration poses significant risks to athletes.
Some of these risks can be attenuated by guidance by a suitably knowledgeable and experienced clinician, and by not attempting to lose too much body weight rapidly pre-competition.
Pre and post competition nutrition and hydration should be planned and modified as required to ensure the athlete is ready to cut weight for competition and at the most healthy weight to fight.