Body temperature and physical performance responses are not maintained at the time of pitch-entry when typical substitute-specific match-day practices are adopted before simulated soccer match-play

Abstract

Objectives: To profile performance and physiological responses to typical patterns of match-day activity for second-half soccer substitutes. Design: Descriptive. Methods: Following a warm-up, 13 male team sports players underwent ∼85 min of rest, punctuated with five min rewarm-ups at ∼25, ∼50, and ∼70 min, before ∼30 min of simulated soccer match-play. Countermovement jump performance (jump height, peak power output), alongside 15 m sprints, were assessed post-warm-up, and pre- and post-simulated match-play. Core temperature, heart rate, ratings of perceived exertion, and blood glucose and lactate concentrations were measured throughout. Results: Warm-up-induced core temperature elevations (∼2.3%, +0.85 °C; p < 0.001) were maintained until after the first rewarm-up. Thereafter, core temperature was reduced from post-warm-up values until pre-simulated match-play (∼1.6%, −0.60 °C; p < 0.001), where values were similar to pre-warm-up (37.07 ± 0.24 °C, p = 0.981). Simulated match-play increased core temperature progressively (p ≤ 0.05) but values remained lower than post-warm-up (∼5 min; p = 0.002) until ∼10 min into exercise. From post-warm-up to pre-simulated match-play, sprint times (∼3.9%, +0.10 s, p = 0.003), jump height (∼9.4%, −3.1 cm; p = 0.017), and peak power output (∼7.2%, −296 W; p < 0.001) worsened. Despite increased ratings of perceived exertion and elevated blood lactate concentrations (p ≤ 0.05), sprint times were maintained throughout exercise, whereas peak power increased (∼7.8%, +294 W; p = 0.006) pre- to post-exercise. Conclusions: At the point of simulated pitch-entry, body temperature and physical performance responses were not maintained from warm-up cessation despite typical substitute-specific match-day practices being employed in thermoneutral conditions. Evidence of performance-limiting fatigue was absent during ∼30 min of simulated match-play. These data question the efficacy of practices typically implemented by substitutes before pitch-entry.