Effects of proanthocyanidin on oxidative stress biomarkers and adipokines in army cadets: a placebo-controlled, double-blind study.

PURPOSE: The relatively recent advent of polyphenol supplement for exercise studies has been tested in a variety of forms and doses. However, the dose-response on adipokines and oxidative stress biomarker effect remains unknown. The aim of the present study was to assess the effect of intense, long-duration (48-h) exercise, and a single dose of proanthocyanidin, on plasma leptin, adiponectin, and electronegative low-density lipoprotein (LDL(-)) concentrations. METHODS: Fifty-four healthy male army cadets (22 ± 2 years) participated in a double-blind, randomized, placebo-controlled study and were distributed between control (CG; n = 27) and supplemented groups (SG; n = 27). Immediately before the start of the exercise, both CG and SG groups received a capsule containing starch (200 mg) or proanthocyanidin (dry Vitis vinifera extract, 200 mg), respectively. Following a 12-h fasting period, the plasma adiponectin, leptin, and LDL(-) concentrations were measured prior to the start of the exercise after 24 and 48 h of military training, and after 24 h of rest. The effects of the proanthocyanidin (supplement), exercise (time), and their interaction were investigated using factorial two-way ANOVA. RESULTS: Plasma leptin concentration was only influenced by exercise (p = 0.001). Plasma adiponectin concentration was influenced by exercise (p = 0.037), and by the exercise x supplement interaction (p = 0.033). LDL(-) was influenced by the supplement (p = 0.001), exercise (p = 0.001), and their interaction (p = 0.001). CONCLUSIONS: A single dose of proanthocyanidin (200 mg) was able to reduce LDL(-) concentration and increase plasma adiponectin concentration after 24 h of rest in SG group, indicating its potential protective action.

Aerobic Conditioning Might Protect Against Liver and Muscle Injury Caused by Short-Term Military Training.

This study aimed to compare the biochemical markers of muscle and liver injury and total antioxidant capacity in army cadets after a traditional army physical training program and to correlate these effects with aerobic conditioning. Male army cadets (n = 87; age, 20 ± 2 years) were evaluated 12 hours before the start of training (T0), 12 hours after a 30-km march (T1), and 48 hours after military training (T2). Creatine kinase (CK), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) serum levels were measured using an autoanalyzer. Total antioxidant capacity was determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (Sc%). Seventy-four percent of army cadets were classified as having excellent aerobic conditioning (53.9 ± 3.0 ml · kg(-) · min(-1) predicted VO2max from the Cooper test). The median serum concentration of all enzymes increased 12 hours after marching (T1: CK 675%; ALT 59%; AST 336%; AST/ALT ratio 85%; p = 0.001) and 48 hours after the end of training (T2: CK 878%; ALT 256%; AST 418%; AST/ALT ratio 180%; p = 0.001). Sc% was higher in T2 (31.1 ± 9.8%; p = 0.01) than in T0 (3.4% change). Maximal oxygen consumption (ml · kg(-1) · min(-1)) correlated negatively with CK (r = -0.25; p = 0.009) and ALT (r = -0.21; p = 0.03) serum levels, and positively with the change in Sc% (r = 0.22; p = 0.04) at T2. The results indicate that intense military training can cause liver and muscle injury and that aerobic conditioning can be considered as a protective factor for these injuries.

Effect of the period of resting in elite judo athletes: hematological indices and copper/ zinc-dependent antioxidant capacity.

The purpose of this study was to evaluate the effect of the resting period on hematological and copper-zinc-dependent antioxidant indices in Brazilian elite judo athletes (n = 7). Venous blood samples were collected after 24-h and 5-d periods of resting following a competition, with an interval of 30 d between collections. Two months prior to and during the study, each athlete received an individualized adequate diet. Body composition was determined at both study periods. The following were analyzed: in whole blood, hemoglobin, hematocrit, red cell count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width, and white cell count; in plasma, zinc, copper, iron, ceruloplasmin, and total iron-binding capacity; in erythrocytes, metallothionein, copper/zinc superoxide dismutase, and osmotic fragility. Dietary intake and body composition did not affect the biochemical measurements. A significant reduction in ceruloplasmin and superoxide dismutase activity was found after 5 d compared to 24 h of resting. A significant correlation between erythrocyte metallothionein and red cell distribution width was observed after 24 h of resting (r = -0.83, p = 0.02), whereas positive correlations of metallothionein with hemoglobin, red cell count, and mean corpuscular hemoglobin concentration were observed after 5 d of resting (r >/= 0.76, p