J Strength Cond Res 2016 Feb;30(2):344-50
1Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom; and2Yorkshire Carnegie Rugby Club, Headingley Carnegie Stadium, St. Michael's Lane, Leeds, United Kingdom.
This study determined the magnitude of change in adductor strength after a competitive match in academy rugby union players and examined the relationship between locomotive demands of match-play and changes in postmatch adductor strength. A within-subject repeated measures design was used. Fourteen academy rugby union players (age, 17.4 ± 0.8 years; height, 182.7 ± 7.6 cm; body mass, 86.2 ± 11.6 kg) participated in the study. Each player performed 3 maximal adductor squeezes at 45° of hip flexion before and immediately, 24, 48, and 72 hours postmatch. Global positioning system was used to assess locomotive demands of match-play. Trivial decreases in adductor squeeze scores occurred immediately (-1.3 ± 2.5%; effect size [ES] = -0.11 ± 0.21; likely, 74%) and 24 hours after match (-0.7 ± 3%; ES = -0.06 ± 0.25; likely, 78%), whereas a small but substantial increase occurred at 48 hours (3.8 ± 1.9%; ES = 0.32 ± 0.16; likely, 89%) before reducing to trivial at 72 hours after match (3.1 ± 2.2%; ES = 0.26 ± 0.18; possibly, 72%). Large individual variation in adductor strength was observed at all time points. The relationship between changes in adductor strength and distance covered at sprinting speed (VO2max ≥ 81%) was large immediately postmatch (p = 0.056, r = -0.521), moderate at 24 hours (p = 0.094, r = -0.465), and very large at 48 hours postmatch (p = 0.005, r = -0.707). Players who cover greater distances sprinting may suffer greater adductor fatigue in the first 48 hours after competition. The assessment of adductor strength using the adductor squeeze test should be considered postmatch to identify players who may require additional rest before returning to field-based training.