Effects of Bilateral or Unilateral Plyometric Training of Lower Limbs on the Bilateral Deficit During Explosive Efforts

Objectives: Bilateral Deficit (BLD) occurs when the force generated by both limbs together is smaller than the sum of the forces developed separately by the two limbs. BLD may be modulated by physical training. Here, were investigated the effects of unilateral or bilateral plyometric training on BLD and neuromuscular activation during lower limb explosive extensions. Methods: Fourteen young males were randomized into the unilateral (UL_) or bilateral (BL_) training group. Plyometric training (20 sessions, 2 days/week) was performed on a sled ergometer, and consisted of UL or BL consecutive, plyometric lower limb extensions (3-to-5 sets; 8-to-10 repetitions). Before and after training, maximal explosive efforts with both lower limbs or with each limb separately were assessed. Electromyography of representative lower limb muscles was measured. Results: BL_training significantly and largely decreased BLD (p=0.003, effect size=1.63). This was accompanied by the reversion from deficit to facilitation of the electromyography amplitude of knee extensors during bilateral efforts (p=0.007). Conversely, UL_training had negligible effects on BLD (p=0.781). Also, both groups showed similar improvements in their maximal explosive power generated after training. Conclusions: Bilateral plyometric training can mitigate BLD, and should be considered for training protocols focused on improving bilateral lower limb motor performance.