Efeito da suplementação do suco de uva no desempeno físico de ratos perante cargas de treino extenuantes

Abstract

To reach their full potential, athletes often lead a strenuous training routine. Although physical training is associated with cardiometabolic health benefits, athletes in overtraining conditions with inadequate recovery triggers oxidative stress and increased systemic inflammation, with a concomitant reduction in sports performance. On the other hand, the literature has shown an increasing number of studies in which fruits are able to improve physical performance due to their antioxidant and antiinflammatory properties. However, so far there are no investigations as to whether these properties minimize the damage caused by overtraining. As the purple grape is one of the fruits with the highest antioxidant capacity, the objective of this study is to evaluate the potential of its derivatives in the attenuation of overtraining parameters induced by a strenuous training protocol in rats. Fifteen male Wistar rats were used, distributed in: control group (CON) (not supplementing and without exercise); trained group (EXC) (not supplemented and trained); exercise group supplemented with grape juice (EXS). The trained animals underwent 11 weeks of training with five weekly sessions up to week 7, with a sharp increase to 2-3 sessions / day until week 11. All groups took physical performance test at the 4th, 8th and 11th week. After this last test the animals performed a behavioral test and echocardiogram, and were later sacrificed for blood collection and liver, brain and heart removal for oxidative stress analysis and the muscles (soleus / extensor longus) for protein expression analysis. When the physical performance was evaluated, in the fourth week the EXS group had an improvement of 80 ± 64% and the EXC group only 25 ± 8%, while the CON group showed a decrease of 24 ± 19%. At week 8 the EXS group improved by 206 ± 62% while the EXC group 136 ± 98%. At week 11 performance increased by 263 ± 80% in the supplemented group but only 154 ± 171 in the EXC group. At this time, the CON group showed only a slight performance improvement of 25 ± 55%. No statistical differences in performance were observed, but Cohen's D indicated an effect size of 1.33 in the fourth week, 0.96 in the 8th week and 0.91 in the 11th week when compared to the active control group. Malondialdehyde and total antioxidant capacity behaved similarly between the groups, as anxiety did not differ between the groups. Thus, it is concluded that the supplementation of grape juice promotes improvement of the physical performance of animals under regular training loads and prevents the stagnation of physical performance under excessive loads. However, this effect is not mediated by attenuation of oxidative stress indicators.