Implementation and Training-Related Outcomes of High-Intensity Interval Training and Cognitive-Motor Training in Professional League of Legends and Valorant Players: A First Exploratory Ecological Study Across In-Game, Cognitive, and Physiological Domains

Background Esports performance relies on in-game, cognitive, and physiological capacities. Its growing professionalization has led to increasing interest in structured out-of-game training interventions as part of performance-support strategies for elite players. However, the feasibility and effects of such interventions in world-class professional players remain unexplored. The present exploratory ecological study examined the implementation of high-intensity interval training (HIIT) and cognitive-motor training (CMT), together with training-related changes in in-game performance, executive functions, and cardiovascular outcomes, under competitive-season constraints in professional League of Legends (LOL; n = 5) and Valorant (VLR; n = 5) players. Data were collected at the team training facility in Berlin, Germany, between May and July 2024. Results Both interventions could be implemented during the competitive season, with 100.00% retention and 98.75% compliance during the first training phase. However, their delivery required substantial adaptations to competitive schedules, players’ day-to-day states, and recovery needs. Moreover, competitive and logistical constraints reduced crossover retention and compliance to 60.00% and 81.25%, respectively. HIIT was perceived as more demanding and CMT as more enjoyable. At the group level, mean reaction time (RT) on the repeatedly administered Dots Task decreased by 10.42% from baseline to the first training phase in the full sample (pFDR = .008; d = 1.37), reflecting an improvement in task-based executive processing speed, although the contribution of the interventions could not be isolated. No consistent group-level improvements were observed in in-game performance or cardiovascular outcomes. Single-case analyses revealed heterogeneous response patterns. In-game changes emerged mainly in specific game- and role-relevant metrics, including performance scores, kill participation, and deaths, with patterns varying across game titles, players, and training phases. RT reductions appeared more consistent across task conditions during HIIT phases and more condition-specific during CMT phases. Cardiovascular responses showed favorable but heterogeneous patterns in resting heart rate (RHR) and heart rate variability (HRV) indices. Overall, responses appeared strongly context-dependent, varying according to game title, player role, individual profile, and daily player state. Conclusions Structured HIIT and CMT can be implemented in world-class professional LOL and VLR players during an active competitive season and may support performance-related outcomes. However, training-related outcomes appear to be heterogeneous and context-dependent and must be contextualized within the complex environment of professional esports. These findings provide preliminary ecological evidence informing structured, individualized, and context-sensitive training approaches in professional esports.