Diminutions of acceleration and deceleration output during professional football match play

Objectives: This study examined distances covered at low (1-2 m s(-2)), moderate (2-3 m s(-2)) and high (>3 m s(-2)) acceleration (L-ACC, M-ACC and H-ACC respectively) and deceleration (L-DEC, M-DEC, and H-DEC respectively) during competitive football games. Temporal and transient patterns of acceleration and deceleration were also examined. Design: Observational, repeated measures. Methods: Thirty-six professional male professional footballers were monitored using a 10 Hz non-differential global positioning system (NdGPS). Match data was organised into six 15 min periods (P1: 1-15 min, P2: 16-30 min, P3: 31-45 min, P4: 46-60 min, P5: 61-75 min, and P6: 76-90 min) for analysis of temporal patterns, and into eighteen 5 min periods for analysis of transient patterns. ANOVA with Bonferroni post hoc tests were used to identify significant (p<0.05) differences between periods. Results: Distance covered at L-ACC, M-ACC, H-ACC, L-DEC, M-DEC, and H-DEC was 424 +/- 75 m, 242 +/- 25 m, 178 +/- 38 m, 365 +/- 54 m, 210 +/- 23 m and 162 +/- 29 m respectively. Between period decrements ranged from 8.0% to 13.2% from P1 to P3, 9.2% to 16.3% from P4 to P6, and from 14.9% to 21.0% from P1 to P6. Following PEAK H-ACC (148% of mean 5 min H-ACC), H-ACC at 5(POST) was 10.4% lower than mean (p < 0.01). Conclusions: Time-dependent reductions in distances covered suggest that acceleration and deceleration capability are acutely compromised during match play. Further, the occurrence of transient fatigue may be supported by the findings that H-ACC and H-DEC performance following PEAK was approximately 10% lower than mean values. (C) 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.