Effect of Three Different Fatigue Protocols on Countermovement Jump Kinetics and Kinematics in Amateur Rugby Union Players

This research investigates how countermovement jump (CMJ) kinetic and kinematic variables respond to three different fatigue protocols with the aim of identifying variables that could be used to monitor and detect fatigue induced by phosphocreatine depletion (80m), metabolite build up (200m) or glycogen depletion (5km). Eight amateur rugby union players completed a different fatigue protocols on three different occasions through a counterbalanced repeated measures design. Using a portable force plate, Jump height (JH) peak velocity (PV), peak power (PP), peak force (PF), mean power (MP), mean force (MF), impulse (IM), and mean impulse (MI) were calculated from the best of three CMJ’s immediately before, after and 15 minutes post intervention. The main findings of the present study were (a) JH, PV and PI significantly (p < 0.05) decreased immediately after all fatigue protocols; (b) JH and PV remained significantly (p < 0.05) decreased 15 minutes after the 5km fatigue protocol; (c) PI and PV remained significantly (p < 0.05) decreased 15 minutes after the 200m fatigue protocol; (d) MP significantly (p < 0.05) decreased immediately after the 80m fatigue protocol. It is suggested that PI, PV and JH could assist in monitoring levels of fatigue after the application of a training stimulus. Changes in PI and PV could be monitored to detect fatigue associated with metabolite build up. Changes in JH and PV could be monitored to detect fatigue associated with glycogen depletion. An indication of the mechanism of fatigue would allow for coaches to prescribe the appropriate loading for training and recovery strategy post match.