The influence of passive heating garments worn in temperate and cold conditions prior to simulated performance for male soccer substitutes

Lengthy periods of inactivity are experienced by substitutes during a soccer match, which can decrease muscle temperature, ultimately impacting performance. This study aimed to determine the effects of using a passive heat intervention in both a cold (2°C) and thermoneutral (18°C) environment on simulated soccer performance and perceptual responses. On four occasions, 14 trained male players, completed a pre-match warm-up, followed by 45 min of rest. After, players completed a half-time re-warm-up, followed by an additional 15 min of rest, simulating 60 min as a substitute. During these periods, players wore tracksuit bottoms (CON), or heated trousers (HEAT), over soccer attire. Once 60 min concluded, participants performed a Soccer Match Simulation (SMS) to assess physical performance. HEAT improved 15 m sprint performance in 2°C (2.8%; p < 0.001) and 18°C (2.6%; p < 0.001) conditions. Further, in HEAT, a significant trial and time effect on countermovement jump height and repeated sprint performance was observed in both 2 and 18°C. Upon match entry, participants felt warmer (p < 0.01), more comfortable (p < 0.01), and felt an increase in match readiness following HEAT, during both conditions. Applying heated garments before match entry for soccer substitutes positively impacts physical performance and match readiness in thermoneutral and cold environments.