Coaches’ verbal encouragement in soccer: A systematic review of its effects on internal training load, physical and time-motion performance, and technical skills

This systematic review synthesized evidence on coaches' verbal encouragement (VE) effects on internal training load, physical and time-motion performance, and technical skills in soccer. PubMed, Web of Science, SPORTDiscus, and PsycInfo were searched up to 1 June 2025, for randomized and quasi-experimental VE interventions in male or female players of any age or competitive level. Outcomes included internal training load (heart rate [HR], blood lactate, perceived exertion [RPE]), physical and time-motion performance (e.g. distance covered, high-intensity running, sprint performance), and technical skills (e.g. passing, dribbling). Methodological quality was assessed using the JBI checklist. Eighteen studies (n = 518) met the inclusion criteria. VE increased internal training load in 11/13 studies, most often showing small-to-moderate increases in RPE and HR responses. Physical and time-motion outcomes improved in 6/8 studies, typically through greater total distance and high-intensity running, and technical performance improved in 8/9 studies (higher success rates and/or increased frequency of technical actions). Effects were most consistent in youth and amateur players; findings in elite youth and professionals were mixed. VE represents a feasible, low-cost strategy that may increase internal training load and enhance selected physical, time-motion, and technical outcomes. Future studies should standardize VE protocols and test dose-response and long-term effects.