The between-match variability of peak power output and Creatine Kinase responses to soccer match-play.

Post-match assessments of peak power output (PPO) during countermovement jumps and Creatine Kinase (CK) concentrations are common markers of recovery status in soccer players. Yet, the impact of soccer match-play on recovery in the 48 h after competition is unclear and the between-match variability of these responses has not been examined. Fourteen reserve team players from an English Premier League club were examined over 1-4 matches per player. CK and PPO were measured before, 24 h and 48 h after each match. Data were analyzed with within-subjects linear mixed models. Compared with the pre-match baseline, PPO was 237+/-170 W and 98+/-168 W lower at 24 h and 48 h, respectively (P<=0.005) and CK was elevated (+24 h: +334.8+/-107.2 [mu][middle dot]L-1, +48 h: +156.9+/-121.0 [mu][middle dot]L-1; both P<=0.001) after match-play. These responses were consistent across the different matches and playing positions (P>0.05). Within-subjects correlations between PPO and CK were significant (r=-0.558; P<=0.005). The between-match variability of PPO was 10.9%, 11.0% and 9.9% respectively at baseline, +24 h and +48 h whereas for CK the variability was 41.7%, 30.0% and 34.3%, respectively. These findings highlight that greater than 48 h is needed to restore metabolic and performance perturbations following soccer match-play and that CK demonstrates greater between-match variability than PPO. Such information is likely to be of interest to those responsible for the design of training schedules in the days following a match and sports scientists whose responsibilities include the monitoring of recovery status in soccer players