Effects of In-Season Velocity- Versus Percentage-Based Training in Academy Rugby League Players

Purpose: To compare the effects of velocity-based training (VBT) versus percentage-based training (PBT) on strength, speed and jump performance in academy rugby league players during a 7-week in-season mesocycle. Methods: Twenty-seven rugby league players competing in the Super League U19s Championship were randomised to VBT (n = 12) or PBT (n = 15). Both groups completed a 7-week resistance training intervention (2x/week) that involved the back squat. The PBT group used a fixed load based on a percentage of one repetition maximum (1RM), whereas the VBT group used a modifiable load based on individualised velocity thresholds. Biomechanical and perceptual data were collected during each training session. Back squat 1RM, countermovement jump (CMJ), reactive strength index (RSI), sprint times, and back squat velocity at 40-90% 1RM were assessed pre- and post-training. Results: The PBT group showed likely to most likely improvements in 1RM strength and RSI, whereas the VBT group showed likely to very likely improvements in 1RM strength, CMJ height, and back squat velocity at 40 and 60% 1RM. Sessional velocity and power were most likely greater during VBT compared with PBT (standardised mean differences [SMDs] = 1.8 to 2.4), whilst time under tension and perceptual training stress were likely lower (SMDs = 0.49 to 0.66). The improvement in back squat velocity at 60% 1RM was likely greater following VBT compared with PBT (SMD = 0.50). Conclusion: VBT can be implemented during the competitive season, instead of traditional PBT, to improve training stimuli, decrease training stress, and promote velocity-specific adaptations