# Effects of Multiple Judo Bouts in the Bilateral Strength Deficit on the Countermovement Jump Metrics

## TL;DR

This study found that repeated judo matches reduce lower limb force production, as measured by changes in jump metrics, indicating progressive fatigue.

## Contribution

The study introduces a novel approach to assess fatigue in judo athletes using bilateral strength deficit and CMJ impulse metrics during multiple simulated bouts.

## Key findings

- CMJ impulse decreased after the third judo bout, indicating reduced force production.
- Bilateral strength deficit in impulse increased after the third bout, showing greater fatigue effects.
- Other CMJ metrics like peak power and jump height remained unchanged across matches.

## Abstract

In official judo competitions, athletes often participate in multiple bouts with short recovery intervals, leading to progressive fatigue that impacts neuromuscular performance. This study examined the acute effects of four simulated judo bouts on bilateral strength deficit (BLD) using metrics from countermovement jumps (CMJs). Thirteen male national-level judo athletes (21.4 ± 2.9 years) participated in the study. Athletes performed both unilateral and bilateral CMJs in randomized order: first at baseline before the initial match, and then after each of the four subsequent matches. The CMJ metrics evaluated included peak and mean power, jump height, peak force, peak velocity, and vertical net impulse. The study used the typical error (TE) and the intraclass correlation coefficient (ICC) to assess relative and absolute reliability. To compare CMJ metrics across the matches, the Friedman test with Conover’s post hoc analysis was conducted, with statistical significance set at p < 0.05. The main findings showed excellent relative reliability, with an ICC greater than 0.85 for all variables in both limbs. Significant effects of the judo matches were observed only in the CMJ impulse (which decreased after the third match) and in BLD of impulse, which increased after the third match (p < 0.05). No statistically significant changes were found in other CMJ metrics. These results suggest that while successive judo bouts induced significant fatigue and force deficits, detectable through changes in impulse, other CMJ metrics remained unaffected. This may indicate that the capacity to generate force quickly in the lower limbs is primarily impacted by successive judo bouts.