Purpose: Changes in body composition of college wrestlers undergoing rapid weight reduction were evaluated over time using magnetic resonance imaging (MRI).
Methods: We 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 one month and one week prior to the weigh-in, on the day of the weigh-in, on the day of the match (after the match), and one 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%); body fat (p<0.05); body water content (p<0.01); trunk cross-section (p<0.05), including separate measurements of trunk viscera, trunk muscle, and trunk fat; quadriceps muscle; lower subcutaneous; and food intake (p<0.01). At one week after the match, all metrics had recovered to their levels measured one 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.