Introduction

Rapid weight loss (RWL) is a growing incidence in the sport of wrestling (^9,10). Collegiate wrestling separates competition into 10 different weight classes. These classes range from 56.8 to 130.0 kg. Many athletes attempting to reach a specific weight class attempt to lose large amounts of weight within a few days before competition. Wrestlers often combine fluid and energy restriction with increased amounts of exercise to lose weight. This RWL that many wrestlers partake in has been shown to promote extreme forms of dehydration (specific gravity of urine >1.030) (⁹). In addition, extreme RWL has tremendously damaging effects on health. These effects were demonstrated in 1997 where in just a 6-week period, 3 NCAA wrestlers died using extreme RWL measures. It should be noted that the NCAA subsequently responded by implementing a weight management program.

Even so, several studies have linked moderate dehydration to significant decrements in aerobic and anaerobic performance in various types of athletes (^1–5,13). Few studies, however, have looked at the effects of RWL on the performance of wrestlers, and those that have provided conflicting results. One study explained that RWL leads to a decrease in peak-power, and an increase in the fatigue-index of male collegiate wrestlers. These authors found that RWL and dehydration negatively impacted the cardiovascular stability of wrestlers (²). However, another study found that although RWL negatively affected the psychological status of wrestlers, it did not significantly affect anaerobic performance (⁸).

The National Collegiate Athletic Association (NCAA) wrestling allows 1 hour of recovery between the official weigh-in and the start of competition for dual matches, and 2 hours of recovery for tournament style matches. Thus, there is a need to exploit the most efficient way to achieve rehydration post weigh-in. Glycerol is a common supplement used by endurance athletes to promote hydration in competition (⁶). No studies have looked at the effectiveness of glycerol on anaerobic performance. Its ability to improve fluid retention is well known (⁶), and thus may aid wrestlers in improving time to rehydration post weigh-in. The purpose of this study was to observe the effects of RWL on anaerobic power in male collegiate wrestlers; in addition, we aimed to see the impact of glycerol on rehydration and anaerobic power. We expected that anaerobic power will decrease with RWL, and that glycerol will promote faster rehydration and an improved anaerobic performance when compared with water (Table 1).

Methods

Experimental Approach to the Problem

Subjects were asked to abstain from caffeine 24 hours before testing. All subjects completed 2 trials in a randomized, counterbalanced design. For both trials, subjects were assessed for nude weight, hydration, and mean anaerobic power output (W_mean) before exercise (pre). Hydration was analyzed through urine specific gravity (ATAGO, Tokyo, Japan) and saliva osmolality (Advanced Instrument 3300, Norwood, MA, USA). If the baseline specific gravity of urine was greater than 1.020, subjects were deemed dehydrated and were asked to reschedule.

Participants ran on a treadmill at 70% of V̇o₂max in a heated room (30° C) until 3% body mass (BM) loss (BML). Hydration and nude weight (subjects used a towel to remove moisture from their skin and hair) were assessed directly after 3% BML (dehydrated). W_mean was assessed at 3% BML.

Subjects then rehydrated drinking either 26 ml·kg⁻¹ of water (control) or a 3% glycerol (treatment) solution containing 26 ml·kg⁻¹ of water and 1 g·kg⁻¹ of glycerol (¹²). Both fluids contained an isocaloric (sugar-free powdered lemonade kcal = 5 FAT = 0 CHO = 0 PRO = 0) flavor to mask any difference in taste. To standardize fluid consumption, subjects were given 20 minutes to drink the first half of fluids, 20 minutes to drink the second half of fluids, and 20 minutes to digest. After 1-hour of rehydration (rehydrated), nude weight, hydration, and W_mean were assessed.

Subjects

Seven male Division II wrestlers were recruited to participate in this study. Subjects completed a control and experimental trial in a counterbalanced order. Before testing, each participant completed a Physical Activity Readiness Questionnaire (PAR-Q) and signed informed consent was obtained. All procedures were approved by the Institutional Review Board at California Baptist University.

Procedures

Preliminary testing consisted of baseline BM, body composition, and aerobic capacity (V̇o₂max). Body composition was measured using American College of Sports Medicine (ACSM's) standard 3-site skin fold for men: chest, abdomen, and thigh. Subjects were given instructions on how to complete a Wingate test, and were briefly familiarized with the test. V̇o₂max was measured using the collection of expired gasses (Viasys Vmax, Yorba Linda, CA, USA). V̇o₂max was successfully achieved when subjects reached at least 3 of the following 4 criteria: respiratory exchange ratio >1.10, heart rate within 10 beats of max (220-age), rating of perceived exertion >18, or V̇o₂ plateau.

W_mean was assessed using a lower-body cycle ergometer (Velotron; RacerMate, Seattle, WA, USA) at pre, dehydrated, and rehydrated. Subjects completed a standardized Wingate test, which included cycling at maximal intensity against 7.5% of BM for 30 seconds. Subjects were weighed, and the resistance was changed accordingly before each Wingate test. Before the start of the test, subjects completed a standardized warm-up of unweighted cycling for 5 minutes.

Statistical Analyses

The data were analyzed using a 2-factor (condition × time) repeated measure analysis of variance and a Tukey post hoc test (STATISTICA).

Results

Participants successfully lost 2.89 ± 0.26% (treatment) and 3 ± 0.31% (control) of their BM from the pre- to dehydrated conditions (Table 2) in 55.83 ± 6.45 minutes (treatment) and 55 ± 7.74 (control).

In addition, hydration statuses (BM, saliva osmolality, and urine-specific gravity [SG]) across all conditions for control and treatment groups are displayed in Table 2. Participants' SG exceeded 1.020 for both the control (1.021 ± 0.008) and treatment (1.023 ± 0.004) groups, which for the purposes of this study deemed them dehydrated. In addition, participants' prevalues for BM, saliva osmolality, and SG significantly differed from dehydrated conditions (p = 0.0001, p = 0.0002, and p = 0.0001). Mean wattage was not significantly different between groups (p = 0.877) and time points, (p = 0.809) (Figure 1).

Discussion

The key finding of this study was that 3% BML did not impair lower-body anaerobic power. Furthermore, rehydrating with 3% glycerol solution did not change hydration levels compared with water consumption. Therefore, our data suggest that if wrestlers can attain ≤3% of ideal weight before weigh-in, anaerobic power will not be hindered.

Although other studies aimed to simulate match like situations, they failed to report or control the specific measures that the participants used to achieve BML (fluid restriction, energy restriction, various types of exercise, or a combination of measures) (^2,8). Those studies, although succeeding in providing strong external validity, compromised their internal validity with lack of control. This study aimed to fill the gap by clarifying the specific effects that acute BML had on anaerobic power. Thus, it was our goal to ensure that each subject was dehydrated in a controlled environment and in a similar fashion.

Unlike Jones et al. (⁵), and Cengiz (²) who showed that RWL decreased anaerobic performance, we found no differences in participants' pre- to dehydrated Wingate performances. The participants in Jones et al. (⁵) were recreationally active males, and likely were not accustomed to significant changes in BM; whereas participants in this study, however, were male collegiate wrestlers who are familiar with RWL. Moreover, Cengiz (²) used methods that pushed wrestlers to lose 5.03 ± 1.01% of BM over the course of 3 days, which presents 2 potential reasons that our data differed. First, the subjects in Cengiz (²) lost a greater amount of relative BM than this study. In addition, this study isolated dehydration by way of controlled, acute RWL (similar to an actual wrestling match), whereas Cengiz (²) did not report or control for the methods that subjects used to achieve 5% BML. Therefore, the decrement in power may have been affected by something other than dehydration.

Our findings align with Marttinen et al. (⁸) who found that anaerobic power did not waiver with BML. Notably, participants in this study, and in Marttinen et al. (⁸), lost less than 5% of their total BM. These data align to show that a moderate amount of RWL (≤5%) does not hinder anaerobic power in male collegiate wrestlers.

Glycerol proved to be just as effective as water as a rehydrating agent. Although several authors have found glycerol to improve fluid retention through hyperhydration (^6,7,11), this study may not have been long enough to see the full effect that either glycerol or water had on fluid retention in rehydration. Although it is understood that glycerol is best used as a hyperhydration aid, it does not have practical implications for the competing wrestler who needs to stay within a specific weight range. In addition, the 1-hour time given for rehydration in this study was purposeful, as the NCAA allocates 1-hour of time between official weigh-ins and the start of competition in dual style matches. Therefore, our data suggest that glycerol did not improve rehydration (compared with water) for wrestlers attempting to rehydrate in a short duration of time.

Practical Applications

Data have shown that BML must exceed 5% before anaerobic performance is significantly hindered (²). Thus, if wrestlers can attain ≤3% of ideal weight before weigh-in, anaerobic power will not be hindered and wrestling performance may be maintained. The current data demonstrate that acute RWL does not negatively affect anaerobic performance, meaning that a wrestler attempting to drop a weight class, resulting in ≤3% BML has the potential to maintain anaerobic power while doing so. These data support the current trend in the literature that dehydration, at 3% BML, does not impair athletic performance.