Effects of creatine supplementation on oxidative stress profile of athletes

Abstract

BackgroundCreatine (Cr) supplementation has been widely used among athletes and physically active individuals. Secondary to its performance-enhancing ability, an increase in oxidative stress may occur, thus prompting concern about its use. The purpose of this study is to investigate the effects of Cr monohydrate supplementation and resistance training on muscle strength and oxidative stress profile in healthy athletes.MethodsA randomized, double-blind, placebo-controlled method was used to assess twenty-six male elite Brazilian handball players divided into 3 groups: Cr monohydrate supplemented group (GC, N = 9), placebo group (GP, N = 9), no treatment group (COT, N = 8) for 32 days. All subjects underwent a resistance training program. Blood samples were drawn on 0 and 32 days post Cr supplementation to analyze the oxidative stress markers, thiobarbituric acid reactive species (TBARS), total antioxidant status (TAS), and uric acid. Creatine phosphokinase, urea, and creatinine were also analyzed, as well. Fitness tests (1 repetition maximum - 1RM and muscle endurance) were performed on the bench press. Body weight and height, body fat percentage (by measuring skin folds) and upper muscular area were also evaluated. Statistical analysis was performed using ANOVA.ResultsOnly GC group showed increase in 1RM (54 ± 9 vs. 63 ± 10 kg; p = 0.0356) and uric acid (4.6 ± 1.0 vs. 7.4 ± 1.6 mg/dl; p = 0.025), with a decrease in TAS (1.11 ± 0.34 vs. 0.60 ± 0.19 mmol/l; p = 0.001). No differences (pre- vs. post-training) in TBARS, creatine phosphokinase, urea, creatinine, body weight and height, body fat percentage, or upper muscular area were observed in any group. When compared to COT, GC group showed greater decrease in TAS (−0.51 ± 0.36 vs. -0.02 ± 0.50 mmol/l; p = 0.0268), higher increase in 1RM (8.30 ± 2.26 vs. 5.29 ± 2.36 kg; p = 0.0209) and uric acid (2.77 ± 1.70 vs. 1.00 ± 1.03 mg/dl; p = 0.0276).ConclusionWe conclude that Cr monohydrate supplementation associated with a specific resistance program promoted a meaningful increase in muscle strength without inducing changes in body composition. The observed significant increase in uric acid and the decrease in TAS suggest that creatine supplementation, despite promoting acute effects on muscle strength improvement, might induce oxidative stress and decreases total antioxidant status of subjects.

Effects of dietary guanidinoacetic acid and betaine supplementation on performance, blood biochemical parameters and antioxidant status of broilers subjected to cold stress

“…Theoretically, if GAA metabolism remains undisturbed and/or low-to-modest quantities of exogenous GAA have been provided, a cumulative effect of the intervention might be neutral or antioxidant protection through creatineand arginine-driven medium. Creatine, the end product of GAA utilization, is thought to have antioxidant capacity in some studies (Sestili et al 2006;Sestili et al 2009), but reduce antioxidant status in others (Percário et al 2012). According to Fathi and Tanha (2015), arginine supplementation increased plasma GPx activity and decreased MDA level in the broiler with cold-induced acites.…”

Ayudas ergogénicas en el deporte

“…Otro efecto importante de la suplementación de creatina es que aumenta la masa libre de grasa (3,4,11,12) y mejora la fuerza muscular y la potencia (3,4,(11)(12)(13). Esto puede ayudar a soportar una mayor carga de entrenamientos, mejorando el rendimiento físico en la competición.…”

Nutritional Interventions as Potential Strategy to Minimize Exercise-Induced Muscle Injuries in Sports

“…Furthermore, although it cannot be excluded that in endurance settings the benefits of supplementation in preventing muscle damage may relate to the antioxidant potential that has been attributed to creatine in various oxidative stressassociated diseases, few studies have been published on the relationship between supplemen-tation and oxidative stress and controversial and not conclusive results are currently available [161][162][163]. In particular creatine supplementation associated with resistance training or exhaustive exercise training has been associated either with reduced oxidative stress [162,164], increased free radical generation and related consumption of antioxidant reserves [161] or no change of lipid peroxidation, resistance of low density lipoprotein to oxidative stress or plasma concentrations of non-enzymatic antioxidants [163]. Taken together these observations show that creatine supplementation before strenuous endurance exercise reduces the increase of markers of cell death/lysis and muscle soreness suggesting a positive effect of the supplementation strategy in maintaining muscle integrity after intense prolonged exercise.…”

“…Indeed when eccentric contraction is avoided as in electrically stimulated gastrocnemius muscle of the rat, creatine supplementation has been found to delay the fatigue appearance, preserve the force development, and prevent the rise of LDH and CK plasma activities and muscle vascular permeability evaluated with Evans blu staining [156]. Furthermore, although it cannot be excluded that in endurance settings the benefits of supplementation in preventing muscle damage may relate to the antioxidant potential that has been attributed to creatine in various oxidative stressassociated diseases, few studies have been published on the relationship between supplemen-tation and oxidative stress and controversial and not conclusive results are currently available [161][162][163]. In particular creatine supplementation associated with resistance training or exhaustive exercise training has been associated either with reduced oxidative stress [162,164], increased free radical generation and related consumption of antioxidant reserves [161] or no change of lipid peroxidation, resistance of low density lipoprotein to oxidative stress or plasma concentrations of non-enzymatic antioxidants [163].…”