Enhancing Lower-Body Power in Highly Trained Female Athletes: Effects of Velocity-Based Strength Training

<b>Background:</b> Only a limited number of studies have examined the effects of short-term, strength-speed-oriented velocity-based training (VBT) on lower-body power in female junior volleyball players and elite female artistic gymnasts. The present study aimed to investigate the impact of a four-week VBT intervention on jump performance and force-velocity characteristics in these athletes. <b>Methods:</b> Seven junior female volleyball players (age: 17.4 ± 0.9 years; height: 179.4 ± 6.5 cm; weight: 74.01 ± 3.5 kg) (top-league team members), and seven elite female artistic gymnasts (age: 17.6 ± 2.9 years; height: 159.6 ± 7.2 cm; weight: 59.3 ± 6.3 kg) (National Team members) completed two weekly training sessions for four weeks, each consisting of four sets of six repetitions of parallel back squats (PBSs) and hip thrusts (HTs). Training loads were regulated using barbell velocity targets (PBSs: 0.46-0.72 m/s; HTs: 0.36-0.60 m/s). Pre- and post-intervention assessments included loaded (15-60% body mass) and unloaded squat jumps (SJs) and countermovement jumps (CMJs) to determine peak power output, jump height, and force-velocity profiles. <b>Results:</b> Volleyball players showed significant improvements in peak power predominantly during loaded SJs (SJ45%: +5.5%, <i>p</i> < 0.01; SJ60%: +5.7%, <i>p</i> < 0.05), whereas gymnasts exhibited greater gains in loaded CMJs (CMJ60%: +7.7%, <i>p</i> < 0.01). In contrast, unloaded SJ and CMJ performances remained largely unchanged for all athletes. Both groups demonstrated a significantly steeper post-intervention force-velocity profile (<i>p</i> < 0.001), indicating an enhanced capacity to produce force at lower movement velocities under external loading. <b>Conclusions:</b> Strength-speed-oriented VBT was effective in improving power production under loaded conditions but had limited transfer to unloaded jump performance. These findings highlight the necessity of subsequent training blocks emphasizing high-velocity, sport-specific movements to optimize explosive performance. Future studies should further investigate low-velocity-loss training protocols as a potential means of enhancing unloaded jump outcomes.