Comparative effects of unilateral versus bilateral lower limb strength training on cartwheel performance in artistic gymnastics athletes

Introduction: Muscle-strengthening exercises in gymnastics are important in supporting somersault movements because they increase power and balance.

Objective: To examine the effects of 8 weeks of unilateral versus bilateral lower-limb strength training on young gymnasts' maximal strength, dynamic balance, and cartwheel performance

Methodology: This study adopts a three-arm randomized controlled trial (RCT) with a pre-test, post-test, and blinded assessor design. Forty-two gymnasts (n=14 each) were randomized to either the unilateral training (UTG), bilateral training (BTG), or control (CG) groups. Using one-leg (unilateral) or two-leg (bilateral) lower-limb exercises, UTG and BTG trained three times a week for eight weeks, while CG continued their routine. The results included 1RM squat and deadlift, dynamic balance (Y-Balance Test, YBT), and cartwheel skill (Cartwheel Performance Assessment Tool, CPAT).

Results: Group × time interactions were significant for all outcomes (p < 0.001). CPAT increased by 2.2 points compared to CG (p < 0.001, d = 1.32) and 1.6 points compared to BTG (p = 0.002, d = 0.94), indicating that UTG had greater skill gains. Compared to BTG (5.9%, p = 0.004, d = 1.02), UTG's dynamic balance improved more (9.4%, p < 0.001, d = 1.68). Bilateral training yielded greater strength gains: 1RM deadlift and squat increased by 6.6 kg (p = 0.02) and 7.7 kg (p = 0.01) over UTG.

Discussion: While bilateral training maximized absolute strength, unilateral training improved skill and balance by more effectively mirroring the demands of gymnastic skills.

Conclusions: While bilateral exercises develop foundational strength, unilateral lower-limb exercises may improve skill execution and stability more effectively in young gymnasts.