The sport of wrestling is contested at the high school and collegiate levels more widely than any other combat sport (i.e., boxing, Judo, etc.). Additionally, wrestling is one of the first sports, which was included in the original Olympic Games (9). Similar to other combat sports, opponents in wrestling are matched based on body mass. Commonly, athletes and coaches believe that wrestling in the lowest possible weight class provides a competitive advantage (2,7). However, many wrestlers weigh quite a bit more (i.e., 2–5 kg) on a daily basis than the limit for the actual weight class in which they will compete. Because of this, utilization of rapid weight loss (RWL) within just days or even hours before the official weigh-in has been a commonly exercised practice to achieve a particular weight class. To achieve RWL, wrestlers have used various strategies, which often include the combination of food restriction and fluid deprivation. However, such approaches can induce deleterious performance effects and even more important may seriously jeopardize an individual's health (1,12,14). Several effective, but dangerous, strategies have been reported to be used by wrestlers to achieve RWL. Notably, dehydration techniques, which include sweating and catharsis (laxatives and forced vomiting), have contributed to the loss of electrolytes and body water (3,14).
As a consequence of these drastic and depleting weight loss techniques, wrestlers typically try to replenish body fluids, electrolytes, and glycogen in the 24-hour period between the official weigh-in and onset of competition. However, reestablishment of bodily fluids may take 12–48 hours and replenishing muscle glycogen may take up to 72 hours (25). Therefore, 24 hours may not be a sufficient time period to replenish bodily fluids and maintain performance. Clearly, body fluids and electrolytes are depleted at the time of competition; the chance of diminished performance is maximized. Indeed, rapid and drastic weight loss seems to adversely influence the wrestler's energy reserves, fluid level, and electrolyte balance (8,23,26). Nevertheless, despite repeated warning by the medical community (1,7,14,15,17) and concern among educators, health professionals, exercise scientists, and young athlete's parents for more than a half-century (2), implementation of RWL techniques to achieve a certain weight class remains popular among competitive wrestlers.
Moreover, previous research has demonstrated these dangerous RWL strategies to be practiced in young individuals, that is, high-school wrestlers (7,11,15), raising cause for concern. Importantly, this research has focused solely on male wrestlers (7,11,15) and male combat sport athletes (12); thus, the practices and subsequent effects of RWL in young female athletes have yet to be elucidated. Examining the strategies and effects of RWL in young athletes and especially young female athletes is of paramount importance since at a young age and in females, absolute body mass is lower. Therefore, any rapid weight fluctuation in young athletes may be at a dangerously high percentage (i.e., 5–10%) of total body mass, which may enhance adverse health and performance effects.
Therefore, the aim of this study was to investigate the magnitude of RWL in young wrestlers competing in the Brazilian high-school games. In addition, a secondary aim was to compare RWL strategies and magnitude between female and male wrestlers. Furthermore, blood analysis was conducted to detect any effects of RWL on markers related to body fluid and electrolyte balance. It was hypothesized that both males and females would engage in RWL techniques; thus, these techniques would result in significantly increased body mass between the official weigh-in at 24 hours before competition and an unofficial prematch weigh-in 24 hours later (i.e., immediately before competition).
Experimental Approach to the Problem
This investigation used a repeated-measures design in which subjects were tested and then retested 24 hours later. Body mass of the subjects was assessed at the official weigh-in, which occurred 24 hours before the onset of competition. Body mass of the athletes was also evaluated immediately before the first round of the competition at a prematch weigh-in 24 hours later (Figure 1). Additionally, athletes answered a hydration habits questionnaire and standardized weight loss questionnaire (10) immediately after the official weigh-in.
A total of 50 athletes (male = 28, female = 22) participated in the Brazilian high-school games; however, 19 wrestlers declined to participate in this study. Thus, this investigation included 31 high-school wrestlers, female (n = 16; 13 ± 2 years) and male (n = 15; 13 ± 2 years, age range: 11–15 yrs), who were competitors of Brazilian high-school games. The experimental procedures were explained to both the subjects and their parents, and written informed consent was given by both the athletes and their parents before participation. All experimental procedures were approved by parents and coaches. The investigation was approved by the Human Research Committee of the University of Campinas (Campinas, Brazil; Protocol #315.827) (04/07/2013).
A time line of procedures can be viewed in Figure 1.
The referee of the competition administered the official weigh-in, and it was held at 10:00 AM the day before competition (i.e., 24 hours before competition). The same investigator administered the unofficial weigh-in for each subject, and this took place 24 hours after the official weigh-in (i.e., 10:00 the next day) just before competition. The same calibrated scale was used for each weigh-in, and measurements were taken to the nearest 0.1 kg.
Fluid Intake Habits
After the official weigh-in, subjects completed a hydration and fluid intake habits questionnaire (5), which was composed of 8 multiple-choice questions. The questionnaire was completed in less than 10 minutes, in a private room, and within the presence of an investigator.
Blood Collection and Analysis
Blood samples, in the amount of 1 ml were collected 15 minutes before the competitive match from the antecubital vein using a syringe without anticoagulant. Sodium (Na2+), potassium (K+), chloride (Cl−), hematocrit (HCT), and hemoglobin (Hb) were assessed immediately before the first competitive match (24 hours after the official weigh-in) to examine body fluid and electrolytes. The iSTAT Blood Gas Analyzer using the disposable cartridge (CG8+) (iSTAT, Abbott, TX, USA) was used to analyze blood samples. The correlation coefficients (r values) used to examine the relationship between conventional and i-STAT were previously reported by Schneider et al. (21) (r = 1.0 for K+; r = 0.86 for Na2+; r = 0.46 for Hb values not corrected for cardiopulmonary bypass (CPB) and r = 0.95 for CPB-corrected Hb; and r = 0.74 for HCT values not corrected for CPB and r = 0.98 for CPB-corrected HCT). The correlation coefficient for HCT between centrifuged and CPB-uncorrected i-STAT values was 0.81 and that for CPB-corrected values was 0.98. Furthermore, according to i-STAT User Manual, systems using the conductivity method measure the electrical conductance of a whole-blood sample. Plasma conducts electrical current, and blood cells act as insulators. A sample with a relatively high hematocrit has, by definition, a larger proportion of its volume filled by the nonconductive red blood cells. The overall conductance of the sample will thus be relatively low. In the i-STAT System, before the measured sample conductance is converted into a hematocrit value, corrections are applied for the temperature of the sample, the size of the fluid segment being measured, and the relative conductivity of the plasma component. The first 2 corrections are determined from the measured value of the calibrant conductance; the last correction is determined from the measured concentrations of sodium and potassium in the sample.
The normality of data was analyzed by the Shapiro-Wilk test. A 2 (group: females and males) by 2 (time: official and prematch weigh-in) mixed-factor analysis of variance was used to detect any difference in body mass between genders from the official to prematch weigh-in. In the event of a significant F-ratio, a Tukey post hoc was performed for pairwise comparisons. Data were reported as mean and SDs, and significance was set at p ≤ 0.05. Additionally, total number of respondents and percentage of respondents was tallied for each questionnaire. Furthermore, a unpaired t-test was used to compare difference in body mass (prematch weigh-in − official weigh-in) (in kilograms) and body mass relative change (in percentage) between genders. A one-sample t-test was used to compare the reference values for Na2+, K+, Cl−, HCT, and Hb and the population values.
Body mass at both weigh-ins and percent change in body mass are displayed in Table 1. A significant increase in body mass was detected from the official weigh-in to the prematch weigh-in in both females and males (females: 2.7 ± 1.4 kg and males: 1.5 ± 0.9 kg; p ≤ 0.05). Furthermore, females gained a significantly greater (p ≤ 0.05) amount of body mass than males between weigh-ins (females: 6.3 ± 3.7%; males: 3.1 ± 1.8%). Additionally, 42% (n = 13) of the subjects admitted to use of RWL practices to achieve a particular weight class. Although, only 13 athletes reported using RWL, all 31 wrestlers increased body mass between weigh-ins, with females increased body mass between 0.5 and 6.1 kg and males increased body mass between 0.3 and 3.3 kg. Subjects reported using RWL techniques starting before the age of 13 (12.1 ± 1.3 years).
Methods of Weight Reduction
The most common methods of RWL among the 13 subjects who reported using RWL were increased amount of exercise (n = 11; 84.6%) and reduced food intake per meal (n = 11; 84.6%) (Table 2).
Side Effects and Performance Effects From Rapid Weight Loss
In terms of side effects from RWL, 8 athletes or 61.5% of the 13 who admitted to use RWL reported side effects. Furthermore, 6 or 46.2% of the 13 who used RWL responded that they believe engaging in these techniques has negatively affected past performance at competitions. The most common reported side effect was fatigue or weakness, followed by cramps and then headache (Table 3). Furthermore, of the 13 athletes who admitted using RWL, 61.5% (n = 8, male = 4, female = 4) perceive that using RWL has previously had negative performance effects (Table 4).
Fluid Intake Habits
Of the 31 respondents, 81% reported that they had previously received educational information regarding proper hydration habits. Similarly, 82% of the athletes indicated that hydration habits are important to health and performance. The most popular liquids for hydration among the athletes were water, soft drinks, and sports drinks, which were ingested by 96, 25, and 22% of respondents, respectively, as part of their regular diet. Additionally, most of the athletes responded that they were concerned about fluid intake during training (51%) and competition (62%). Regarding time of fluid intake, 45% of subjects reported consuming liquid before the onset of thirst, whereas 41% reported waiting until after feeling thirsty to ingest any liquid.
There was no difference between (p > 0.05) any blood parameter (i.e., sodium, potassium, chloride, hematocrit, and hemoglobin) between the prematch weigh-in and normal range reference levels (iSTAT User Manual) (Table 5).
The primary aim of this study was to investigate the magnitude of body mass increase in the 24 hours before competition among male and female high-school wrestlers. Furthermore, this study examined which methodologies were used by young wrestlers to achieve RWL leading up to competition and its effects on perceived performance and hydration status. The main findings support the initial hypotheses; in that (a) RWL was commonly used (i.e., 42.0% of the population) and (b) both female (2.7 kg) and male (1.5 kg) high-school wrestlers experienced a significantly increased body mass within the 24 hours before competition indicating RWL. Additionally, it was observed that body mass increased to a greater extent in female wrestlers (6.3% of total body mass) compared with male wrestlers (3.1% of total body mass) between weigh-ins. The most common RWL techniques were reduced food intake per meal and increased physical activity. Moreover, 46.2% of wrestlers who reported using RWL techniques reported side effects such as fatigue and weakness (n = 11), cramps (n = 4), or headache (n = 4). Additionally, of 61.5% of the wrestlers who used RWL perceived that RWL had negatively impacted previous performance; yet, the wrestlers continued to implement the strategy. Interestingly, respondents appeared to be well educated on fluid intake habits (81% reporting previous education); yet, many still practiced RWL. Finally, athletes had hydration/body water and electrolyte status assessed by various biomarkers (sodium, potassium, chloride, hematocrit, and hemoglobin). Despite many individuals using RWL, all blood parameters were within the normal range compared with iSTAT reference levels, when assessed immediately before competition.
To the best of the authors' knowledge, this study was the first to investigate changes in body mass, use of RWL, and hydration status through blood markers in both female and male high-school wrestlers before an official competition. Previously, Kordi et al. (9) observed an average body mass increase of 1.3 kg in male wrestlers in the 24-hour period between official and prematch weigh-ins. These data suggest comparable RWL and subsequent body mass increase to this study as it was observed a body mass increase of 1.5 kg between weigh-ins in male wrestlers. Because Kordi et al. (2012) examined only male subjects, this study achieved novelty by analyzing female wrestlers' RWL strategies and observing a 2.7 kg (6.3%) body mass change between weigh-ins. Moreover, Kordi et al. (10) revealed that 62% of Iranian wrestlers surveyed practiced weight loss before competition. The findings of this investigation along with Kordi et al. (2011) add information to previous research that has demonstrated a varying but large (25–67%) use of RWL strategies among combat athletes (11,16,24) to achieve a specific weight class. Furthermore, previous data suggest that weight loss techniques for wrestling are not limited to 24 hours before competition as 41% of US college wrestlers experience a 5.0–9.1 kg·wk−1 decline in body mass during competition season (22).
Interestingly, previous literature has reported diminished performance among combat athletes who use RWL to achieve a particular weight class (12,14). Similarly, the results of this study show that 46.2% of athletes perceived decreased past performance after the usage of an RWL strategy. Moreover, the American College of Sports Medicine reports that increased physical activity and dietary restriction are the 2 most popular methods of RWL, and that dietary restriction may lead to dehydration (14). However, although increased physical activity and dietary restriction were exercised by 84.6% of the athletes in this study who reported usage of RWL, no significant decrease (p > 0.05) in biomarkers of hydration status in comparison with the iSTAT manual was observed (Table 5). Although a reduction in hydration status was expected and has been shown in previous research to occur as a result of RWL (8,23,26), a further analysis indicates the specific RWL strategies implemented, and well-educated status of this investigation may have been beneficial in deterring impaired hydration. For example, 84.6% of those using RWL simply ate less at each meal rather than not eating all day (46.2%). Moreover, 81% of the study population had received previous education on appropriate fluid intake habits and 82% believed proper hydration to be important. This education and concern may have contributed to only 23.1% of athletes reporting fluid restriction as an RWL technique. Furthermore, approximately 50% of athletes reported ingesting liquids even before thirst sets in, which likely reduced the incidence of dehydration and possible negative effects on stroke volume and blood flow to the active muscle, which has been shown to increase perceived exertion (4). Additionally, the use of laxatives has been noted in previous research (3,14) as an RWL method and may lead to vomiting and consequently negatively affect hydration status. However, only 15.4% of athletes in this investigation reported laxative use. Therefore, despite high incidence of RWL usage in this study; previous education, low incidence of fluid restriction, and minimal use of laxatives may account for the lack of decline in hydration status in this investigation.
In addition to examining the acute effects of RWL on performance and hydration status, it is necessary to note the chronic harm associated with recurring weight cycling and use of RWL techniques, for example, cardiovascular system dysfunctions or even temporary interruption of growth (2). This is increasingly troublesome as Artioli et al. (2) reported the average age of a weight-class athlete to begin RWL and weight cycling is 12.1 years, which is before or during puberty. Furthermore, although it has been noted that weight-class athletes compete in a lower class than they normally weigh to take advantage of a lighter opponent (2,7), this investigation suggests that athletes perceived that RWL has negatively affected past performance. Specifically, 61.5% of those who acknowledge using RWL believe that this strategy had deleterious effects on previous wrestling performance (Table 4). This is not surprising as previous authors have suggested RWL to weaken a wrestler's body for competition (14) and potentially lower resting concentration of anabolic hormones (18), which may disrupt growth, suppress immune function and renal blood flow, and decrease glomerular filtration volume (6,13,18,19). Therefore, in addition to possible acute decrement in performance due to RWL, a wrestler needs to be cognizant of the possible long-term detriments RWL may have to overall health.
Furthermore, although previous authors have reported 12.1 years as the average age when weight-class athletes begin weight cycling (2), there are reported cases of weight cycling even younger. Most concerning is Sansone and Sawyer (20) reported an incidence of a 5-year-old child who was encouraged by his father to exercise unsafe weight loss practices to reduce up to 10% of body mass. The report of RWL at such a young age is troubling and suggests that parents, coaches, and mentors play strong role in influencing the health of a young child. Moreover, in addition to negative physiological effects, significant adverse psychological effects may occur in a prepubescent child who is being taught to practice unhealthy weight loss techniques.
In conclusion, this study demonstrated that (a) 42% of respondents used RWL techniques before the official weigh-in, (b) both female and male high-school wrestlers experienced significant body mass increase within 24 hours before competition (females: 2.7 kg, 6.3%; males: 1.5 kg, 3.1%) with females increasing body mass significantly more than males, (c) 46.2% of those who admitted to use RWL reported adverse side effects, and (d) despite RWL observed in this study, hydration status was not negatively affected as the biomarkers measured (sodium, potassium, chloride, hematocrit, and hemoglobin) immediately before competition were similar to normal iSTAT reference values. It seems that RWL strategies are common among female and male high-school wrestlers, and performance detriments may occur. Although, prior knowledge of appropriate hydration habits may mitigate dehydration. It is important to note that a relatively small sample size was implemented in this study and a larger sample size would be desired in further investigations. However, this investigation is the first to assess the incidence and magnitude of RWL in young female wrestlers before competition. Importantly, it must be noted that some athletes may have used RWL and not reported it. To illustrate this point, although only 13 athletes (42%) reported using RWL, all 31 athletes examined in this study increased body mass from the official to prematch weigh-in. When including all females (n = 16), the range of body mass increase was 0.5–6.1 kg and for all males (n = 15), the range of body mass increase was 0.3–3.1 kg. Therefore, it seems that although some athletes acknowledge usage of RWL, the total incidence of RWL may be underreported.
From practical perspective, it is true that RWL will allow an athlete to reach a particular weight class for competition; however, this may not be desirable for acute performance or short- and long-term health. Often a sport coach makes the decision for an athlete to decrease body mass and this also implements the strategy; yet, this may not be appropriate. Rather, it may be necessary for a sport coach to consult a registered dietitian and strength and conditioning coach to implement appropriate exercise and nutritional strategies to achieve gradual weight loss rather than RWL to maintain health and performance. It also must be noted that although a coach or athlete desires to compete at a certain weight, this does not mean that they should do so. Of concern, the average age of athletes in this study was only 13 years old; yet, in the 24 hours before competition, males gained 3.1% and females gained 6.3% of total body mass. Therefore, in young athletes, a healthy body mass should be desired and chronic health be of paramount concern. Finally, previous education does seem effective at combatting negative hydration habits, thus continued education should be available for young children regarding nutrition and exercise.
The authors would like to thank FAEPEX-UNICAMP (Grant: 519.292-130/13) and CAPES (Grant: AEX 2312/13-1) for financial support. It is also important to acknowledge the high level of commitment of all athletes, coaches, and the Brazilian Wrestling Confederation staff to the experimental procedures conducted in this investigation.
1. American College of Sports Medicine Position stand on weight loss in wrestlers. Med Sci Sports Exerc 8: xi–xiii, 1976.
2. Artioli GG, Franchini E, Lancha Junior AH. Weight loss in grappling combat sports: review and applied recommendations. Braz J Kinanthropometry Hum Perform 2: 92–101, 2006.
3. Artioli GG, Scagliuse FB, Polacow VO, Gualano B, Lancha Junior AH. Magnitude and methods of rapid weight loss in elite judo athletes. Braz J Nutr 20: 307–315, 2007.
4. Brito C, Marins J. Measurement of fluid reposition during judo practices. Minas-State J Phys Ed 15: 144–152, 2007.
5. Ferreira FG, Altoé JL, Silva RP, Tsai LP, Fernandes AA, Brito CJ, Marins JCB. Level of knowledge and hydration strategies of young soccer players. Braz J Kinanthropometry Hum Perform 11: 202–209, 2009.
6. Filaire E, Maso F, Degoutte F, Jouanel P, Lac G. Food restriction, performance, psychological state and Lipid values in judo athletes. Int J Sports Med 22: 454–459, 2001.
7. Housh TJ, Johnson GO. Growth in Young Wrestlers—Current Comments. Indianapolis, IN: American College of Sports Medicine, 2008.
8. Houston M, Marrin D, Green H, Thomson J. The effect of rapid weight loss on physiological functions in wrestlers. Phys Sportsmed 9: 73–78, 1981.
9. Kordi R, Nourian R, Rostami M, Wallace WA. Percentage of body fat and weight gain in participants in the tehran high school wrestling championship. Asian J Sports Med 3: 119–125, 2012.
10. Kordi R, Ziaee V, Rostami M, Wallace WA. Patterns of weight loss and supplement consumption of male wrestlers in Tehran. Sports Med Arthrosc Rehabil Ther Technol 3: 4, 2011.
11. Lakin JA, Steen SN, Oppliger RA. Eating behaviors, weight loss methods, and nutrition practices among high school wrestlers. J Community Health Nurs 7: 223–234, 1990.
12. Mendes SH, Tritto AC, Guilherme JP, Solis MY, Vieira DE, Franchini E, Lancha AH Jr, Artioli GG. Effect of rapid weight loss on performance in combat sport male athletes: Does adaptation to chronic weight cycling play a role? Br J Sports Med 47: 1155–1160, 2013.
13. Ohta S, Nakaji S, Suzuki K, Totsuka M, Umeda T, Sugawara K. Depressed humoral immunity after weight reduction in competitive judoists. Luminescence 17: 150–157, 2002.
14. Oppliger RA, Case HS, Horswill CA, Landry GL, Shelter AC. American College of Sports Medicine position stand. Weight loss in wrestlers. Med Sci Sports Exerc 28: ix–xii, 1996.
15. Oppliger RA, Harms RD, Herrmann DE, Streich CM, Clark RR. The wisconsin wrestling minimum weight project: A model for weight control among high school wrestlers. Med Sci Sports Exerc 27: 1220–1224, 1995.
16. Oppliger RA, Landry GL, Foster SW, Lambrecht AC. Bulimic behaviors among interscholastic wrestlers: A statewide survey. Pediatrics 91: 826–831, 1993.
17. Rodriguez NR, DiMarco NM, Langley S. Nutrition and athletic performance. Med Sci Sports Exerc 41: 709–731, 2009.
18. Roemmich JN, Sinning WE. Weight loss and wrestling training: Effects on growth-related hormones. J Appl Physiol (1985) 82: 1760–1764, 1997.
19. Rowell NA. Painful bleeding syndrome associated with increased fibrinolytic activity. Br J Dermatol 91: 591–596, 1974.
20. Sansone RA, Sawyer R. Weight loss pressure on a 5 year old wrestler. Br J Sports Med 39: e2, 2005.
21. Schneider J, Dudziak R, Westphal K, Vettermann J. The i-STAT analyzer. A new, hand-held device for the bedside determination of hematocrit, blood gases, and electrolytes. Anaesthesist 46: 704–714, 1997.
22. Steen SN, Brownell KD. Patterns of weight loss and regain in wrestlers: Has the tradition changed? Med Sci Sports Exerc 22: 762–768, 1990.
23. Steen SN, McKinney S. Nutrition assessment of college wrestlers. Phys Sportsmed 14: 100–105,108, 1986.
24. Tipton CM, Tcheng TK. Iowa wrestling study: Weight loss in high school Students. JAMA 214: 1269–1274, 1970.
25. Widrick JJ, Costill DL, Fink WJ, Hickey MS, McConell GK, Tanaka H. Carbohydrate feedings and exercise performance: Effect of initial muscle glycogen concentration. J Appl Physiol (1985) 74: 2998–3005, 1993.
26. Woods ER, Wilson CD, Masland RP Jr. Weight control methods in high school wrestlers. J Adolesc Health Care 9: 394–397, 1988.