Effects of sleep restriction on cognitive and physical performance in elite karate athletes: A randomized crossover study

BACKGROUND: Sleep deprivation negatively impacts athletic performance; however, limited research has specifically examined these effects in combat sports athletes, where rapid decision-making and neuromuscular coordination are crucial for success. This study aimed to investigate the impact of partial sleep restriction on cognitive and physical performance in elite karate athletes. METHODS: Fourteen international-level male karate athletes (age: 23.35 ± 4.61 years) completed 2 randomized experimental sessions separated by 1 week: following regular sleep (8 hours) versus sleep restriction (4 hours). Cognitive performance was assessed using the Stroop test, simple reaction time, and multiple-choice reaction time tests. Physical performance was evaluated through the squat jump, modified agility T-test (MAT), and karate-specific aerobic test. RESULTS: All tests were conducted before and after exercise. Sleep restriction significantly impaired cognitive performance. Stroop reaction times increased under sleep restriction (F = 13.0, P