Introduction:
The potential ergogenic effects of L-arginine, a conditionally essential amino acid involved in nitric oxide (NO) synthesis, on anaerobic exercise performance remain inconclusive.

Aim of the study:
This study investigated the potential for L-arginine supplementation to improve anaerobic exercise performance in healthy young adults

Material and methods:
A randomized, double-blind, placebo-controlled, cross-over design was employed, with nine participants (7 males, 2 females; mean age 23.67 ± 4.09 years) completing two laboratory visits. Participants consumed either 2 grams of L-arginine or a placebo (dextrose) in cranberry juice, followed by a 30-minute rest period before performance testing. Tennis-specific exercise tests were selected, including grip strength, vertical jump height, and anaerobic cycling performance (Wingate test).

Results:
Results indicated no significant differences between L-arginine and placebo conditions in peak power output (p = 0.57), relative peak power output (p = 0.65), average power output (p = 0.69), or fatigue index (p = 0.70) during the Wingate test. Similarly, no significant differences were observed in vertical jump height (p = 0.73) or power output (p = 0.73). However, grip strength was significantly lower in the L-arginine condition compared to placebo (p = 0.03).

Conclusions:
These findings do not support the hypothesis that acute L-arginine supplementation enhances anaerobic exercise performance.