Performance-enhancing effects of caffeine and L-Theanine among Iranian elite wrestlers: a focus on cognitive and specific physical performance.

BACKGROUND

Caffeine is a well-known ergogenic aid that can enhance physical and cognitive performance. However, it often induces side effects, such as anxiety and overstimulation, which can be problematic in high-pressure sports like wrestling. L-theanine, a non-stimulant amino acid found in tea, may help mitigate these effects by promoting a calm yet focused mental state. This study aimed to investigate the acute effects of caffeine, L-theanine, and their combination on physical performance, cognitive function, and anxiety in elite male wrestlers.

METHODS

In a double-blind, placebo-controlled, crossover design, 12 elite male wrestlers (21.8 ± 2.1 years) completed four test sessions under randomized conditions: placebo (PLA), caffeine (CAF; 3 mg/kg), L-theanine (THE; 3 mg/kg), and caffeine + L-theanine (CAF+THE; 3 mg/kg each). After 60 minutes, athletes performed the wall-squat test, vertical jump height (VJH), medicine ball throw (MBT), handgrip strength, and the Specific Wrestling Fitness Test (SWFT). Cognitive function was assessed pre- and post-SWFT using a computerized Stroop test. Anxiety was assessed using the State-Trait Anxiety Inventory (STAI), and side effects were recorded.

RESULTS

CAF+THE outperformed PLA in wall-squat time ( = 0.001), MBT ( = 0.005), VJH ( = 0.011), and grip strength ( = 0.004). SWFT throw count was highest in CAF+THE versus all other conditions ( < 0.001). Post-SWFT Stroop reaction time was faster in CAF+THE than PLA ( = 0.004) and THE ( = 0.036), and accuracy was also higher ( = 0.009 vs PLA). CAF alone increased state anxiety compared to PLA ( = 0.021), while CAF+THE reduced anxiety to below placebo levels (8% incidence vs 33%). Trait anxiety was lower in CAF+THE compared to CAF ( = 0.018). The prevalence of caffeine-induced tachycardia (92%) was notably reduced under CAF+THE (17%).

CONCLUSION

CAF+THE (3 mg/kg each) enhances elite wrestlers' strength, endurance, cognitive speed, and accuracy while reducing anxiety and physiological side effects commonly associated with caffeine alone. This combination represents a safe, practical supplement strategy for combat sports athletes who must maintain explosive performance and mental control under stress. Coaches are encouraged to trial CAF+THE protocols during training to personalize timing and dosage.