Stable or Unstable? Evaluating the Strength Outcomes of 12-Week Resistance Training in Youth Judo Athletes

<b>Background</b>: The purpose of this study was to compare the effects of resistance training on stable versus unstable surfaces on strength performance in young judokas. <b>Methods</b>: The study included 18 young judokas (age: 13.2 ± 1.2 years) with 4.7 years of training experience assigned to either the URT (unstable resistance training) group or the STG (stable resistance training) group. Both groups performed the bench press and squat exercise for 12 weeks (3 sessions/week, 30-40 min each), with one group performing on the stable surface and the other on the unstable surface. The tests included the 1RM bench press and squat, maximal power output during bench press and squat (Pmax), abdominal strength test (AB60), and the standing long jump (SLJ). <b>Results</b>: Statistical analyses revealed a group × time interaction for AB60 (<i>p</i> < 0.02) in favor of the URT group. Significant main effects of time (<i>p</i> < 0.01) for the 1RM bench press, 1RM squat, bench press power, AB60, and SLJ were found. There were no significant effects for squat maximal power in both groups (<i>p</i> ˃ 0.05). <b>Conclusions</b>: Both unstable and stable resistance training effectively improved maximal strength and performance in adolescent judokas, with unstable training offering additional benefits in abdominal strength.