Changes in body mass and hydration status in judo athletes before and after a top-level competition: a descriptive case study

ABSTRACT

Objectives

The International Judo Federation (IJF) implemented new regulations in an attempt to regulate rapid weight loss in 2013. The body weight of the athletes cannot be more than 5% higher than the upper limits of their weight categories at the weight check for randomly selected athletes from each weight category before the competition. However, therea lack of studies demonstrating rapid weight loss and hydration status of elite judo athletes in a real match atmosphere under the current refereeing rules. Thus, this study aimed to examine the body mass and hydration changes of elite judo athletes a week before the competition, official weigh-in, and 24 hours after competition.

Methods

Eight high-level male judo athletes voluntarily participated in this study. Body mass and urinary measures of hydration status were collected a week before, at the official weigh-in and 24-hour post-weigh-in.

Results

The one-way repeated-measures ANOVA showed a significant main effect of time on body mass (p < 0.001). Body mass decreased by 5.4 ± 0.7 kg or 6.8% from a week before the competition to official weigh-in (p < 0.001) and increased by 3.0 ± 1.1 kg or 4.2% from official weigh-in to 24-h post-competition (p < 0.001). A significant effect of time was also found in both urine-specific gravity (USG) (p < 0.001) and urine color (UC) among the measurements (p = 0.001). Athletes’ USG values were at the highest level (USG = 1.030 ± 0.001) at the official weigh-in, while they decreased significantly at 24-hour post-competition (USG = 1.017 ± 0.007).

Conclusion

The results showed that elite judo athletes resort to rapid weight loss and present dehydration despite established regulations by the IJF.

KEYWORDS:

• Weight gain
• hypohydration
• combat sports
• weight loss
• urine specific gravity

Acknowledgments

The authors would like to acknowledge Dr. Jozef Simenko for his review of the manuscript. BC designed and conceptualized the study and performed measurements; BC and SSB analyzed the data; BC, ORB, and SSB drafted the manuscript; BC, ORB, and SSB edited and revised the manuscript. All authors approved the final version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported that there is no funding associated with the work featured in this article.