A eficácia da suplementação aguda de L-arginina no desempenho físico relacionado ao treinamento de força : uma revisão sistemática e meta-análise

Abstract

The oral administration of L-arginine has been related to an improvement in physical performance due to a probable decrease in muscle fatigue, resulting from the vasodilator effect of nitric oxide on skeletal muscle. However, there is no clear and quantitative analysis of information and distinction about the performance capacity and the effects involved in anaerobic activities in the literature. Objective: To evaluate the effectiveness of L-arginine supplementation on physical performance in strength training with a systematic review and meta-analysis. Methods: Systematic review and meta-analysis performed according to PRISMA® (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) PICOS statement and methodology guidelines, quality of evidence by Grading of Recommendations Assessment, Development and Evaluation (GRADE) and the tool Evaluation of Multiple Systematic Reviews (AMSTAR2) to evaluate a methodological evaluation of studies. The identification of the selection process was carried out in the Cochrane, PubMed, MEDLINE, LILACS and SciELO databases and the period of study selection was from 2010 to 2020. Studies with the following characteristics were included: (1) well-planned experiments that included supplementation of L-arginine alone (with no additional compounds); (2) identical experimental condition in placebo or control group; (3) test the effects of L-arginine supplementation on sports performance related to strength training; (4) clinical trial. Results: There was no significant heterogeneity (p>0.05) in any analysis of the three selected articles and the effects of L-arginine supplementation on performance in muscle endurance obtained mean of 0.26 (95% CI = -0.129; 0.649; p = 0.190), mean peak torque of -0.002 (95% CI = -0.531; 0.527; p = 0.99) of the third set of exercises and, furthermore, when comparing the integrated effect of resistance rate with peak of torque, there was no difference with a mean of 0.168 (95% CI = -0.145; 0.481; p = 0.292). Conclusion: Acute L-arginine supplementation has no ergogenic effect on strength training performance.