Impact Of “Extra-time” On Performance And Physiological Responses To Simulated Soccer Match-play

The physiological and performance responses to 90 min of soccer-specific exercise are well known. However, the responses to 120 min of soccer-specific exercise (i.e., inclusion of an extra-time period; ET) are unclear. This is despite the importance of ET in determining match outcomes in tournament match-play. PURPOSE: To profile the performance and physiological responses to 120 min of simulated soccer match-play. METHODS: Following protocol habituation, 12 amateur soccer players (22 ± 3 y; estimated V[Combining Dot Above]O2max: 55.8 ± 1.6 mL·kg·min-1) completed 120 min of soccer-specific exercise, covering 14.4 km. Performance indices (15 m and 20 m sprint speeds, countermovement jump height (CMJ), dribble speed and precision) were measured during the protocol. Blood was collected during exercise to assess blood glucose and lactate, plasma glycerol, non-esterified fatty acids (NEFA), and creatine kinase (CK) concentrations. Core temperature (Tcore) and perceived exertion (RPE) were also measured. RESULTS: Compared to baseline, 20 m sprint speed was reduced after ET (–8 ± 8%) and 45 min (–6 ± 8%, p<0.05). CMJ height was reduced after ET compared to baseline (–11 ± 10% p<0.05). Sprint speeds over 15 m were reduced during ET compared to all time-points (–3 ± 4% vs. 76-90 min, p<0.05). Glucose concentrations were lower during ET (3.9 ± 0.7 mmol·L-1) compared to all time-points, except the first 15 min of the second half (p<0.05). Lactate concentrations were lower in ET than the first half (–2.5 ± 2.2 mmol·L-1). Glycerol and NEFA concentrations were higher (p<0.05) in ET compared to 90 min (+59 ± 42% and +37 ± 24%, respectively). ET increased RPE relative to the first 90 min (16 ± 3 vs. 13 ± 2, p<0.05) and Tcore was elevated during the last 15 min of ET (38.7 ± 0.8°C) compared to the first 15 min of ET (38.1 ± 0.7°C, p<0.05) and the first 15 min of the second half (38.0 ± 0.1°C, p<0.05). CONCLUSIONS: The ET period negatively impacts performance and physiological responses compared to 90 min of simulated match-play. Reductions in blood glucose and lactate with increases in plasma NEFA and glycerol may indicate endogenous CHO depletion and increased fat oxidation during ET. Future research is required to investigate interventions that attenuate decrements in performance and physiological perturbations