BARTOK, C., D. A. SCHOELLER, R. R. CLARK, J. C. SULLIVAN, and G. L. LANDRY. The Effect of Dehydration on Wrestling Minimum Weight Assessment. Med. Sci. Sports Exerc., Vol. 36, No. 1, pp. 160–167, 2004. Given that some wrestlers arrive for minimum weight (MW) testing in a dehydrated condition, it is important to understand the effects of dehydration on MW assessment methods.
Purpose: To determine the effect of dehydration on the assessment of MW by three-site skinfolds with the Lohman formula (SF), leg-to-leg bioelectrical impedance analysis (BIA), and multifrequency bioelectrical impedance spectroscopy (BIS) compared with a four-component (4C) criterion.
Methods: Twenty-two male collegiate wrestlers (mean ± SD, age: 19.9 ± 1.4 yr, height: 174.0 ± 6.8 cm, body mass: 77.4 ± 9.1 kg) had their body composition assessed by the 4C criterion, hydrostatic weighing (HW), SF, BIA, and BIS in euhydration (EUH) and dehydration (DEH). Subjects dehydrated 2–5% of body weight through fluid restriction and exercise in a hot environment.
Results: In EUH, the total error (TE) for HW (1.75 kg) and SF (2.15 kg) were not significantly different, but the TE for HW and SF methods were significantly lower than the TE for both BIS (3.68 kg) and BIA (3.77 kg). In DEH, SF, BIA, and BIS methods had a TE approaching or exceeding 4 kg (8.8 lb). Dehydration increased the TE for SF and BIA through an artificial lowering of body weight and for BIS by an increased error in intracellular water prediction.
Conclusion: Acute thermal dehydration violates assumptions necessary for the accurate and precise prediction of MW by SF, leg-to-leg BIA, and multifrequency BIS.
Over 250,000 high school and college athletes participate in the sport of wrestling each year (23,26). To maintain fairness and prevent injuries, wrestlers are paired with opponents of similar weight through the use of weight classes. In order to “make weight” for competitions, some wrestlers dehydrate and restrict food intake, placing themselves at increased risk for health problems (15). To control these practices, several states have implemented minimum weight (MW) programs to regulate high school wrestling (8), and the National Federation of State High School Associations has recommended that all states have MW programs in place by 2004 (25). In addition, the National Collegiate Athletic Association implemented a MW program regulating collegiate wrestling in 1998 (24). These MW programs assign wrestlers a minimum competition weight based on body composition testing (8).
The NCAA Competitive Safeguards Committee has approved hydrostatic weighing (HW), skinfolds (SF) using the Lohman equation (18), and air displacement plethysmography (36) for collegiate MW assessment (24). At the high school level, MW assessment is made using HW, SF, or in some states, bioelectrical impedance analysis (BIA) (25). Several studies have established the validity of SF testing in high school and collegiate wrestlers (6,9,10,35) and have demonstrated potential for the use of whole-body (7,29) and leg-to-leg (37) BIA techniques. However, concerns have arisen about the effects of dehydration (DEH) on MW assessment by these techniques (7,9). DEH reduces body weight and total body water, alters the distribution and compartmentalization of body water, lowers the hydration of fat-free mass, and alters the density of fat-free mass (11,28).
This is a significant area of concern because recent research has demonstrated that some wrestlers arrive for MW testing in a dehydrated state to secure a lower predicted MW. Unannounced reweighing of wrestlers within days of MW testing showed that almost 25% had gained more than 1.4 kg (3 lb), with a maximum weight gain of over 8 kg (18 lb) (8). In response to this problem, the NCAA and some high school programs have added hydration testing to the MW testing protocol. Wrestlers must produce a urine sample with a specific gravity ≤ 1.020 before assessment of MW to demonstrate adequate hydration (24,25). However, concerns remain about the sensitivity and specificity of urine specific-gravity testing as well as the ability to mask signs of DEH with acute ingestion of hypotonic fluids (28).
In theory, DEH violates assumptions critical to the estimation of MW by HW, SF, and impedance methods. However, to date, there are no published studies specifically aimed at understanding the effects of DEH on MW assessment. The goals of this study were to assess the accuracy and precision of MW assessment techniques under strictly controlled conditions of adequate hydration (euhydration, EUH) and DEH as well as to determine the effects of DEH on these MW assessment techniques. The test techniques included SF, leg-to-leg BIA, and proximal tetrapolar multifrequency bioelectrical impedance spectroscopy analysis (BIS). We hypothesized that all techniques would have unacceptable total errors (>4 kg) in DEH due to violations of body composition assumptions critical to these techniques.