Effects of L-Theanine and L-Arginine supplementation on attention, cognitive, and shooting performance in elite air rifle shooters

Buzdağli Y., Canyurt F., Raşit Inaç M., OZAN M., Çağlar B., Köse D.

International Journal of Sport and Exercise Psychology, 2026 (SSCI, Scopus)

Abstract

This study aimed to investigate the acute effects of L-theanine (L-THE), L-arginine (L-ARG), and their combined supplementation on shooting performance, cognitive function, and attention in elite air rifle shooters. Fifteen elite female 10-m air rifle shooters participated in a randomised, double-blind, placebo-controlled, crossover study. Participants completed four experimental conditions: placebo (PLA), L-THE, L-ARG, and combined L-THE*L-ARG. Sixty minutes after supplementation, the d2 Attention Test and Stroop Colour–Word Test were administered, followed by a standardised 60-shot air rifle performance trial in accordance with International Shooting Sport Federation (ISSF) rules. L-THE and combined L-THE*L-ARG supplementation significantly improved shooting performance compared with placebo, with the highest scores observed in the combined condition. Stroop test results indicated that reaction times were reduced under L-THE supplementation and were fastest in the combined group. The d2 Attention Test revealed improvements in processing speed, net performance, and concentration, together with reductions in error and fluctuation rates; these effects were again most pronounced under combined supplementation. L-THE supplementation improved both cognitive performance and shooting accuracy in elite air rifle athletes. Although the effect of L-ARG alone was limited, its co-administration with L-THE produced greater synergistic benefits. These findings suggest that L-THE and L-ARG may serve as potential ergogenic aids in sports requiring sustained attention and fine motor control.