Effects of grape juice consumption on muscle fatigue and oxidative stress in judo athletes: a randomized clinical trial

Abstract

Physiological levels of reactive oxygen species (ROS) are important for intracellular and extracellular redox regulation in signaling and defense processes. Strenuous exercise can also contribute to this imbalance, and the muscle fatigue, evidenced by impaired strength or power generation, can be caused by various reasons, including oxidative stress. Antioxidants can prevent the formation of ROS by intercepting free radicals. Twenty judo athletes were included in this randomized, double-blind clinical trial into grape juice and placebo groups, and they consumed grape juice or placebo daily for 14 days in a crossover model. The outcomes were analyzed before and after combat simulations. The upper limb strength was higher in the grape juice group than in the placebo (p [group] = 0.003). The lipid damage levels were 10% higher in the placebo group (p [interaction] = 0.048). During the pre-exercise, the placebo group showed 19% more DNA damage than the grape juice group. The superoxide dismutase activity was 80% lower in the grape juice group (p [interaction] < 0.001). The consumption of grape juice can improve parameters of oxidative stress by reducing the lipid and DNA damage.

Isotonic Drinks Based on Organic Grape Juice and Naturally Flavored with Herb and Spice Extracts

“…The results of TPI (Table 3) and antioxidant activity evaluation (Figure 3) demonstrate that the prepared beverages presented a good source of phenolic content and antioxidant capacity. Furthermore, we previously demonstrated [53] the contribution of grape juice to isotonic beverages, citing different studies that demonstrated the positive effect of grape juice consumption during physical activities, which improves antioxidant activity and performance, protects against oxidative damage, and reduces inflammation [14,[54][55][56][57][58][59][60]. Accordingly, it is known that herbs and spices have excellent antioxidant activity.…”

Bilberry/red grape juice decreases plasma biomarkers of inflammation and tissue damage in aged men with subjective memory impairment –a randomized clinical trial

“…Also, the resveratrol component of red-grapes has been shown to reduce oxidative stress (lower malondialdehyde, nitrite levels and restoration of GSH activity) in AD rats along with improving cognitive dysfunction [ 56 ]. Furthermore, several clinical intervention trials with grape juice indicate possible protection against DNA damage and oxidative stress [ 19 , 57 ].…”

New Insight and Future Perspectives on Nutraceuticals for Improving Sports Performance of Combat Players: Focus on Natural Supplements, Importance and Advantages over Synthetic Ones

“…Antioxidant and prooxidant activities were also demonstrated to be altered by rapid weight loss in judo athletes [197]. Supplementation with grape juice for 14 days was proven to increase antioxidant capacity, reduce lipid and DNA damage and increase upper limb strength in a double-blind study including 20 judokas [198]. Kendo athletes benefitted from reduced muscle injury after Q10 coenzyme supplementation in a double-blind 18-participant study [199].…”