Investigação dos efeitos da suplementação oral de arginina no aumento de força e massa muscular

Abstract

Introduction: Oral administration of arginine has been associated with physical performance improvement due to probable decrease of muscular fatigue derived from the vasodilatation factor of the nitric oxide over the skeletal muscles. Objective: to evaluate the effects of oral administration of L-Arginine during an exercise program with weights. Methods: 20 male individuals, randomly divided in two groups: A and B, were submitted to eight weeks of training with weights (three times per week). Group A used 3 grams of L-Arginine + vitamin C during the eight weeks and group B used only vitamin C (control group). Results: After eight weeks of training, group A presented body weight values and lean mass significantly higher (p < 0.05), body fat percentage significantly lower (p < 0.05), and strength of lower limbs significantly higher (p < 0.05), while group B did not present significant differences for the same period. Conclusion: Oral administration of arginine associated with a training program with weights increased the stimuli of the exercise to the skeletal muscles level, enabling hence, increase of muscular strength and mass.

Interferência da L-arginina e do exercício físico sobre a morfologia do músculo estriado esquelético em ratos jovens

“…However, there is not record in the literature of studies which evaluate such macroscopic parameter, relating it with physical exercise and ingestion of this amino acid. It is believed that muscle contraction derived from physical exercise practice may lead to hypertrophy of the muscle fibers 10 , which reflects on increase of length of the skeletal muscle venter. Additionally, L-arginine, due to promotion of vasodilation in the skeletal muscle, could boost this hypertrophy due to greater blood and nutrients contribution for this muscle in activity 9,10 .…”

“…It is believed that muscle contraction derived from physical exercise practice may lead to hypertrophy of the muscle fibers 10 , which reflects on increase of length of the skeletal muscle venter. Additionally, L-arginine, due to promotion of vasodilation in the skeletal muscle, could boost this hypertrophy due to greater blood and nutrients contribution for this muscle in activity 9,10 . The results of this study evidence that there was no significant difference between the mean diameter of the fibers of the animals which perform physical exercise when compared with the sedentary group.…”

“…Vasodilation results in increase of muscular perfusion and greater glucose availability by the muscles in activity 9 . It Is believed that the perfusion of the skeletal musculature effect itself contributes to the better training quality, resulting in increase of muscle mass and contractile strength 10 . Besides the L-arginine effects related to vasodilation, there is also association of this amino acid with improvement of contractile strength through better synthesis of muscle proteins 11 .…”

Estratégias nutricionais para minimizar o dano muscular induzido pelo exercício de força

“…Lomonosova et al (2014), com 500mg.kg -1 de ARG administrada com água de modo contínuo, por 48h antecedentes a um protocolo de "down-hill", observaram melhora de 37% no teste de desempenho em corrida 24h após a realização do exercício comparado ao grupo sem suplemento. Já em seres humanos, alguns estudos com ARG têm reportado aumento na produção de força a longo prazo (ANGELI et al, 2007;CAMBELL et al, 2006;KRAEMER et al, 2009), necessitando de mais estudos que examinem o desempenho muscular em respostas à suplementação com ARG após DMIE.…”

“…Essa dose é decorrente de estudos preliminares que apontaram sua superioridade quanto a doses menores, 1,5g (NISSEN et al, 1996) e ausência de efeitos adicionais com dose mais elevada, 6g (GALLANGHER et al, 2000). Nissen et al (1996) reportaram resultados superiores com o uso de 3g/dia de HMβ na força, na redução da CK e da proteólise muscular, avaliada por meio da concentração de 3-metilhistidina urinária ( Particularmente no TF, a suplementação de ARG tem demonstrado influenciar a composição corporal, promover aumento da força máxima e torque isocinético CAMPBELL et al, 2006;ANGELI et al, 2007 Diante as lacunas apresentadas na literatura a respeito da eficiência da suplementação com aminoácidos (LEU e ARG), e do metabólito de aminoácido (HMβ), em atenuar o DMIE, e da escassez de dados presentes na literatura, faz-se necessário a realização de novos estudos, conforme proposto no presente projeto.…”