Mental Fatigue in Olympic Combat Sports: The unseen ongoing battle

Rafael Kons^1,2*Chao Bian²Kevin De Pauw²Marc Theeboom²Hebe Schaillee²Daniele Detanico³Bart Roelands²

• ¹Federal University of Bahia (UFBA), Salvador, Brazil
• ²Vrije Universiteit Brussel, Brussels, Belgium
• ³Universidade Federal de Santa Catarina, Florianópolis, Brazil

Combat sports, including judo, boxing, wrestling, taekwondo, and fencing, are popular worldwide and key to the upcoming 2028 Summer Olympics (IOC, 2025). Due to their growing relevance, research on these Olympic combat sports has expanded in recent years, focusing on physical (e.g., neuromuscular) and psychological (e.g., motivation) parameters (Duarte & Pavani, 2025;Kons et al., 2025;Doron et al., 2021). One-on-one combat typically involves high physical and cognitive demands (Ruddock et al., 2021). Generally, Olympic combat sports competitions consist of multiple matches held on the same day, often separated by short intervals/transitions (Kons et al., 2020). Meanwhile, the work-to-rest ratio (W/R) varies according to the specific group of the combats, reflecting differences in intensity patterns across striking, grappling, and weapon-based disciplines, from the perspective of performance and assessment (Chaabene et al., 2018). Table 1 presents the W/R for Olympic combat sports by discipline and group, ranging approximately from 1:9 to 9:1. Combined with the short rest time from official competitions (e.g., average 16.1 seconds between two pauses in the world championship Sabre bout (Tarrago et al., 2023)), these values emphasize the high intensity inherent in these sports with a very brief time window to recover. The highly intermittent, but prolonged competition format (i.e., congested matches in one day) suggests the buildup of fatigue in athletes, making it a key factor to be considered to actively manage on mat, ring, and piste. Evidence has shown that the elevated intensity can result in significant physical fatigue accumulation throughout competition in different combat sports, as an example judo (Detanico et al., 2015;Kons et al., 2018;Kons et al., 2021), taekwondo (Chiodo et al., 2011;Chiodo et al., 2012), and wrestling (Kraemer et al., 2001;Barbas et al., 2011). A systematic review conducted by Kons et al. (2020) verified the effects of matches on physical fatigue in different combat sports and showed a decrease in physical performance in the upper and lower limbs, due to cumulative fatigue. However, these results were more evident in the grappling combat sport group, while striking modalities exhibited a different pattern, suggesting distinct behaviors between the two groups.The physical aspect of combat sports has been extensively researched. However, despite recognition that fatigue is multidimensional (Oliver et al., 2025) and important for athletic performance, the mental/cognitive counterpart (i.e., mental fatigue and cognitive performance) remains underexplored, especially given the different time structures across disciplines (Table 1). This is particularly relevant as athletes must make rapid decisions during attacks and counterattacks (Russo & Ottoboni, 2019), anticipate opponents' actions within technical-tactical behaviors (Zhang et al., 2022), and execute complex motor skills in unpredictable, high-pressure environments (Ciaccioni et al., 2025;Doron et al., 2021). Olympic combat sports require strong perceptual-cognitive skills such as visual tracking (Krabben et al., 2022;Piras et al., 2014), selective attention (Sanchez-Lopez et al., 2024), and inhibitory control (Faro et al., 2020), which are critical for maintaining strategic focus and effective decision-making under pressure (Krabben et al., 2019). Moreover, athletes must manage high cognitive loads related to both environmental and situational demands, including adapting tactics, interpreting an opponent's actions, responding to coaches, ignoring distractions, and monitoring match status (e.g., score, time, and number of matches) (Krabben et al., 2019). These challenges engage executive functions, which select, regulate, and coordinate behaviors in dynamic scenarios. Consequently, mental fatigue may arise from the sustained cognitive effort in combat (Schampheleer & Roelands, 2024). At the elite level, performance depends not only on physical capacity but also on efficient allocation of limited mental resources during critical moments (Krabben et al., 2019;Varesco et al., 2023).Although mental fatigue has been shown to impair physical, psychomotor, technical, and tactical performance in a variety of sports (Schampheleer & Roelands, 2024;Van Cutsem et al., 2017), its actual presence and effects in Olympic combat sports have been largely overlooked. This is surprising given the high perceptual-cognitive demands these disciplines characterize (Krabben et al., 2019) and their essential role in a competition success. In this context, the present opinion paper aims to explore the current state of research on mental fatigue in some Olympic combat sports (e.g., judo, taekwondo and fencing), highlighting existing evidence and proposing future directions for investigation. Specifically, it discusses how mental fatigue can impact both training and competitive settings in different Olympic combat sports. Furthermore, this paper contributes to the broader discourse beyond physical performance, emphasizing their potential in enhancing neurocognitive demands and mental effort imposed by matches and training. In this regard, this opinion paper highlights an underexplored perspective in combat sports research by drawing attention to the significant cognitive demands inherent in match situations and emphasizing the need for a deeper understanding of their implications on the performance of Olympic combat sport athletes. Few investigations explored the effects of mental fatigue on performance in Olympic combat sports.In general, studies used the computerized Stroop task, social media exposure, and specific demand for combat (e.g., quantify during official competition) to verify performance outcomes (Campos et al., 2019;Faro et al., 2025;Bian et al., 2025a;Bian et al., 2025b;Bian et al., 2025c;Varesco et al., 2023Varesco et al., , 2025)). Campos et al. (2019) explored the effects of mental fatigue on judo athletes' performance, aiming to verify whether cognitive exertion influenced physical, physiological, and perceptual responses during a specific judo test (Special Judo Fitness Test). Considering two experimental situations: one under controlled conditions and the other following the inducement of mental fatigue via a 30-minute Stroop task. The results showed increased perceptions of fatigue and effort, but no effect on judo-specific test performance or physiological responses, suggesting that mental fatigue did not significantly impact judo-specific test performance in judo athletes. However, it is important to emphasize that the study verified the effect of this situation on a specific judo test, which, despite reflecting some demands similar to judo (Franchini et al., 2011;Julio et al., 2017), does not reproduce its complexity (e.g., coaching instructions, noises, and monitoring match status) (Krabben et al., 2019).Furthermore, the study's small and varied sample size may have impacted responses.In indicating impaired cognitive processing. The social media use did not significantly affect fatigue or neuroelectric markers, and no difference was found for visual-motor performance related to the taekwondo-specific task in all conditions. Taking into account the specificity of taekwondo, this study brings a relevant point related to visual-motor performance, important for carrying out specific actions (e.g., kicks) (Sant'Ana et al., 2017;Greco et al., 2024). However, it does not reproduce the real situations in which taekwondo athletes are subjected to in competition (Chiodo et al., 2011;Chiodo et al., 2012), and does not simulate the work-to-rest ratio of the matches.In fencing, a higher number of studies have been carried out over the last few years. (Andreato et al., 2022;Varesco et al., 2025), should be considered to provide a more comprehensive understanding of Olympic combat sports performance under mental fatigue. Moreover, a key limitation in current research is the predominant reliance on the Stroop task and laboratory-based settings, which may reduce ecological validity and limit the applicability of findings to real-world competition scenarios. Finally, understanding sport-related aspects that most induce mental fatigue in individual sports, as combat modalities, may help athletes and coaches to adopt strategies to improve mental health and performance throughout the athlete's career.