In the latest study addressing health and safety consequences from rapid extreme weight cutting in combat sports, the Journal of Translational Medicine published results noting that rapid extreme weight cuts caused skeletal muscles to be “damaged to a significant extent” in judokas.

In the recent study, titled “The effects of rapid weight loss on skeletal muscle in judo athletes” the authors tested 18 competitive judoka for myoglobin, creatine kinase, aldolase, hemoglobin, and hematocrit values on seven consecutive days.  Measures were taken in two different phases, the first after rigorous training, the second after the athletes underwent rapid extreme weight cuts.  The cuts required the athletes to lose at least 5% of their body weight in 7 days using methods such as “increased physical activity, plastic suit training, caloric deficit, reduced fluid intake and sauna in order to rapidly lose weight during the last 3 days.”.

The data indicated that the judoka were physiologically worn-out following the rapid weight cuts concluding that “Our study provides evidence that skeletal muscles are damaged to a significant extent and that athletes who undergo rapid weight loss (RWL) and strenuous exercise would likely not be able to perform at peak levels during competition.”.

The full abstract reads as follows:

Objective

To observe the effect of rapid weight loss (RWL) methods over 3 days on muscle damage in judokas.

Methods

Eighteen judokas participated in this crossover study, meaning that judo athletes were subjected to exercise-only phase (4 days) and RWL phase (3 days). Subjects were tested for myoglobin, creatine kinase, aldolase, hemoglobin, and hematocrit values on seven consecutive days. These biomarkers served as indicators of acute muscle damage.

Results

During the exercise-only phase, no significant changes were observed. Myoglobin (Mb) (p < 0.001), creatine kinase (CK) (p < 0.001) and aldolase (ALD) (p < 0.001) significantly increased only during the RWL phase, as well as hemoglobin (Hb) (p < 0.001) and hematocrit (Hct) (p < 0.005) values. It was detected that peak values for muscle damage biomarkers were reached on the sixth day, while Hct and Hb values were the highest on the seventh day of the study.

Conclusion

Our study showed significant muscle damage induced by RWL. The prevalence of RWL use by judokas is high but firm scientific evidence is lacking in the evaluation of the current practice of it. Therefore, further knowledge must be gained to evaluate the effectiveness of RWL on performance and its impact on judokas’ wellbeing.