Acute effects of overload strength training on vertical jump performance in young female volleyball players

The vertical jump performance is one of the most used parameters for the evaluation of lower limb strength in volleyball. Indeed, vertical jumps are frequently performed by volleyball players during the match both in defensive and offensive actions. This study aimed to evaluate the acute effects of a 90-minute strength training session (STS) with different overload intensities on vertical jump performance and on rating of perceived exertion (RPE) in young female volleyball players. Ten young female volleyball players (14.00±1.01 years; 165±0.03 cm; 58.33±10.25 kg; 21.52±3.84 kg/m2) were included in this randomized crossover study. The participants were subjected to the three following STS: STS-A without overload; STS-B with 10% body weight (BW) overload; and STS-C with 20% BW overload. The RPE for the three sessions was recorded using the modified 20-point Borg Scale. For the evaluation of lower limb strength, the following tests were used: squat jump (SJ), countermovement jump with hands on the hips (CMJ), and countermovement jump with arm swing (CMJ-AS). Although a significant interaction was detected after the STS, no significant changes were observed among the three sessions (i.e., STS-A, STS-B, and STS-C). No differences were detected in the Borg Scale across the three sessions. This study showed that a STS administered without load or with an overload of 10% or 20% of BW, does not lead to significant changes on vertical jump performance in young volleyball players.