Rate of Force Development Adaptations After Weightlifting-Style Training: The Influence of Power Clean Ability.J Strength Cond Res. 2022 Jun 01; 36(6):1560-1567.JS
James, LP, Suchomel, TJ, Comfort, P, Haff, GG, and Connick, M. Rate of force development adaptations after weightlifting-style training: the influence of power clean ability. J Strength Cond Res 36(6): 1560-1567, 2022-This experiment examined changes to the rate of force development (RFD) expressed under loaded jump conditions between individuals with a higher (stronger) and lower (weaker) weightlifting performance (as assessed by the 1 repetition maximum [RM] power clean) after training with the weightlifting derivatives. Two groups of markedly different weightlifting ability undertook 10 weeks of training with the power clean variants, snatch pulls, and jump squats across heavy and light conditions. Testing was performed at baseline, after 5 weeks of training (mid-test) and after training (post-test). During testing, RFD was assessed under a series of loads (20-80% squat 1RM) through the jump squat. Furthermore, the force-velocity relationship, and unloaded jump strategy (through the force-time curve waveform), were also examined. Very large change (Hedge's g, 95% confidence interval [g] = 2.10, 1.24 to 4.16) in RFD at 20% 1RM at mid-test occurred within the stronger group. Conversely, a small increase (g = 0.27, 0.53-1.91) among the weaker subjects existed in this measure at mid-test, reaching a moderate increase at post-test (g = 0.71, -0.18 to 2.15). Limited improvements were seen by the stronger subjects in RFD at 60 and 80% 1RM at either mid-test (60%: g = 0.27, -0.75 to 1.33; 80% = 0.02, -1.01 to 1.00) or post-test (60%: g = 0.52, -0.38 to 1.80; 80% = -0.26, -1.23 to 0.77). The stronger group experienced a shift throughout the force-velocity relationship while a more force-dominant adaptation occurred in weaker subjects. Differences in jump strategy between groups were also noted. Such training will elicit practically different adaptations in rapid force production depending on the individual's baseline weightlifting ability.