Prevalence, techniques and knowledge of rapid weight loss amongst adult british judo athletes: a questionnaire based study.

Background: No investigation has analysed the RWL approaches since new rules by the International Judo Federation (IJF) regarding weigh-ins have been implemented in international competitions in 2014. The current study analyses the prevalence, most common methods and knowledge surrounding the effects of rapid weight loss (RWL) amongst adult UK judo athletes. Additionally, it examines differences in rapid weight loss behaviour (RWLB) between gender, weight-class, competitive level, age RWL began and "high"/"low" knowledge athletes.

Methods: A previously validated questionnaire developed to assess RWL in judo athletes was modified by adding a knowledge section and revalidated for content. The questionnaire provided a RWLB score (higher score equated to more aggressive RWL) and a knowledge score (out of 10). 256 athletes (189 males and 66 females, aged 18-67 years) completed the questionnaire between February and April 2015. Unpaired t test, one-way ANOVA-tests and Chi-squared tests were used to test differences of mean RWLB scores and prevalence between groups.

Results: The prevalence of RWL was 84%. The most common methods of RWL were increased exercise and decreased food/fluid intake. The mean knowledge score was 6.2±2.8, with most incorrect answers regarding physiological effects of RWL. No significant differences in RWLB scores were found between gender, "high"/"low" knowledge athletes or weight-classes. Statistically significant differences in RWLB scores were found between different competitive levels (p=0.014) and age RWL began (p<0.01) in males but not in females.

Conclusion: RWL is highly prevalent in the UK adult judo population and athletes have moderate knowledge surrounding its effects. In males, RWLB is most aggressive in elite level athletes and those that began RWL at a younger age. Therefore, updated rulings to target elite and youth level athletes should be implemented to reduce dangerous RWL.

Level of evidence: IV.