Abstract

Abstract
Purpose – This study aimed to assess whether a supramaximal loaded squat using variable resistance can enhance countermovement jump (CMJ) performance via Post-activation Potentiation (PAP) to a greater degree than using traditional methods of resistance training.
Methods – Male participants (n = 8) were recruited from the University of Lincoln Rugby Union team and assessed for baseline countermovement jump (CMJ) and squat one-repetition maximum (1RM) values. An additional three visits were required of the participants completing three varying barbell squat protocols in a randomised crossover trial. The three protocols involved lifting a submaximal load of 6 reps of 60% 1RM, a near-maximal load of 4 repetitions at 90% 1RM, and a supramaximal load achieved via variable resistance of 3 repetitions at 110% 1RM. Participants rested for eight minutes and performed another CMJ to assess any differences in jump height, peak power/weight and peak velocity from baseline measures.
Results – There were no significant differences between the different protocols and overall power differences from pre- to post-protocol (P = 0.713). However, there was a significant difference in CMJ peak power and peak velocity from pre- to post- protocol when all three protocols were grouped (P < 0.01).
Conclusion – The findings indicate that a back squat will improve subsequent jump power and velocity when loaded between 60-110% 1RM when volume is controlled.