Strength and power development in professional rugby union players over a training and playing season

Purpose: To investigate strength and power development in elite rugby players during the different phases of a professional season. Methods: Sixteen professional rugby union athletes from an English premiership team were monitored for measures of lower body peak force, force at 50 ms, force at 100 ms (all isometric squat), and power (explosive hack squat). Athletes were assessed at the start of pre-season (T1), post pre-season (T2), mid-way through the competitive season (T3) and at the end of the competitive season (T4). Effect size statistics with magnitude based inferences were calculated to interpret differences in physical performance between the different stages of the season. Results: Very likely beneficial increases in force at 50 ms (+16%, ES = 0.75 ± 0.4) and 100 ms (+14%, ES = 0.63 ± 0.4) were observed between T1-T2. A likely beneficial increase in power was observed between T2-T3 (+4%, ES = 0.31 ± 0.2). Between T3-T4, decreases in force at 50 ms (-6%, ES = -0.39 ± 0.3) and 100 ms (-9%, ES = -0.52 ± 0.4) occurred whilst peak force and power were maintained. Over the full season (T1-T4) clear beneficial increases in all measures of strength and power were identified. Conclusions: Meaningful increases in strength and power can be achieved in professional English premiership rugby players over a full playing season. The greatest opportunity for strength and power development occurs during pre to mid-season phases whilst these measures are maintained or decrease slightly during the latter stages of a season.