MRI evaluation of body composition changes in wrestlers undergoing rapid weight loss

Purpose: Changes in body composition of college wrestlers undergoing rapid weight reduction were evaluated over time using magnetic resonance imaging (MRI). Methods: This study evaluated 12 wrestlers ( male, 18 22 years of age) who participated in Japan's 2005 intercollegiate wrestling tournament. For this study, MRI ( of the right femoral region and the trunk), as well as measurements of body weight, body fat percentage and body water content, were performed 1 month and 1 week prior to the weigh-in, on the day of the weigh-in, on the day of the match ( after the match), and 1 week after the weigh-in. A survey of food and fluid intake was also conducted. Results: Several variables were significantly lower on the day of the weigh-in than one month prior: body weight (p < 0.01, -7.3% (SD 1.6%)); body fat ( p < 0.05, -9.3 (5.8)%); body water content (p < 0.01, -5.9 (1.6)%); trunk cross-section (p < 0.01, -13.2 (4.4)%), including separate measurements of trunk viscera, trunk muscle, and trunk fat; quadriceps muscle; lower subcutaneous; and food intake ( p < 0.01, 122 ( 20)). At 1 week after the match, all metrics had recovered to their levels measured 1 month before the weigh-in. Certain variables that were highly sensitive to hydration recovered more rapidly: they had reached their initial levels when measured immediately after the match. Conclusion: Rapid weight reduction reduced the wrestlers' cross-sectional areas of muscle and fat tissues, which tended to recover through rehydration after the weigh-in. These results suggest that rapid weight reduction of wrestlers induced changes in different regions of the body.