The aim of this study was to investigate the effect of Rhodiola rosea supplementation on the balance of oxidants and antioxidants in the serum and erythrocytes of competitive rowers. This double-blinded study included 22 members of the Polish Rowing Team who were participating in a preparatory camp. Participants were randomly assigned to the supplemented group (n = 11), who received 100 mg of R. rosea extract twice daily for 4 wk, or the placebo group (n = 11). At the beginning and end of the study, participants performed a 2,000-m maximum test on a rowing ergometer. Blood samples were taken from the antecubital vein before each exercise test, 1 min after completing the test, and after a 24-hr restitution period. The following redox parameters were assessed in erythrocytes: superoxide dismutase activity, glutathione peroxidase activity, and thiobarbituric-acid-reactive substances concentrations. In addition, creatine kinase activity and total antioxidant capacity were measured in plasma samples, lactate levels were determined in capillary blood samples, and uric acid concentrations were measured in serum. After supplementation, the total plasma antioxidant capacity was significantly higher (p = .0002) in the supplemented group than in the placebo group, and superoxide dismutase activity in erythrocytes directly after and 24 hr after the ergometry was significantly (p = .0461) lower in athletes receiving R. rosea extracts than in the placebo group. In conclusion, supplementation with R. rosea increased antioxidant levels in the plasma of professional rowers but had no effect on oxidative damage induced by exhaustive exercise.

The aim of the study was to investigate the influence of an increased intake of anthocyanins, contained in chokeberry juice, on the redox parameters in rowers performing a physical exercise during a 1-month training camp. The athletes were randomly assigned to receive 150 mL of chokeberry juice daily, containing 23 mg/100 mL of anthocyanins (supplemented group), or placebo (control group). Before and after the supplementation period, the subjects performed an incremental rowing exercise test. Blood samples were taken from the antecubital vein before each exercise test, 1 min after the test, and following a 24-h recovery period. After the supplementation period, TBARS concentrations in the samples collected 1 min after the exercise test and following a 24-h recovery period were significantly lower in the subjects receiving chokeberry juice than in the control group. In the supplemented group, glutathione peroxidase activity was lower in the samples collected 1 min after the exercise test, and superoxide dismutase activity was lower in the samples taken following a 24-h recovery, as compared to the subjects receiving placebo. These findings indicate that an increased intake of anthocyanins limits the exercise-induced oxidative damage to red blood cells, most probably by enhancing the endogenous antioxidant defense system.

BackgroundThe aim of this study was to analyze the effect of supplementation with chokeberry (Aronia melanocarpa) juice on the levels of pro-inflammatory cytokines, hepcidin, and selected markers of iron metabolism in rowers subjected to exhaustive exercise.MethodsThis double-blind study included 19 members of the Polish Rowing Team. The subjects were randomly assigned to the supplemented group (n = 10), receiving 150 mL of chokeberry juice for 8 weeks, or to the placebo group (n = 9). The participants performed a 2000-m test on a rowing ergometer at the beginning and at the end of the preparatory camp. Blood samples were obtained from the antecubital vein prior to each exercise test, one minute after completing the test, and after a 24-hour recovery period. The levels of hepcidin, interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), ferritin, iron, uric acid, and myoglobin were determined, as well as the total iron-binding capacity, unbound iron-binding capacity, and total antioxidant capacity (TAC).ResultsPost-exercise, there was a significant increase in IL-6 and a significant decrease in the TAC in both groups, prior to and after supplementation with chokeberry juice. At the end of the experiment, the supplemented athletes showed significantly lower post-exercise levels of TNF-alpha and significantly higher TACs and iron levels than the controls.ConclusionSupplementation with chokeberry juice results in an increase in the antioxidant activity of plasma and contributes significantly to reducing the TNF-alpha level.

iron-binding capacity, unbound iron-binding capacity, iron, red blood cells, hemoglobin, hematocrit, mean corpuscular volume, creatine kinase, and myoglobin. Result The high-intensity exercise test caused significant changes in hepcidin levels, IL-6, and iron metabolism parameters, with their subsequent return to baseline values during the recovery period. The serum iron levels decreased significantly during the recovery compared with pre-and post-exercise levels. Conclusion These results suggest that the high-intensity ergometric test was reflected by a marked decrease in serum level of iron during the recovery period, but did not induce concomitant changes in the remaining erythrocyte parameters.

High-intensity physical exercise decreases intracellular antioxidant potential. An enhanced antioxidant defense system is desirable in people subjected to exhaustive exercise. The aim of this study was to investigate the influence of supplementation with artichoke-leaf extract on parameters describing balance between oxidants and antioxidants in competitive rowers. This double-blinded study was carried out in 22 members of the Polish rowing team who were randomly assigned to a supplemented group (n = 12), receiving 1 gelatin capsule containing 400 mg of artichoke-leaf extract 3 times a day for 5 wk, or a placebo group (n = 10). At the beginning and end of the study participants performed a 2,000-m maximal test on a rowing ergometer. Before each exercise test, 1 min after the test completion, and after a 24-hr restitution period blood samples were taken from antecubital vein. The following redox parameters were assessed in red blood cells: superoxide dismutase activity, glutathione peroxidase activity, glutathione reductase activity, reduced glutathione levels, and thiobarbituric-acid-reactive-substances concentrations. Creatine kinase activity and total antioxidant capacity (TAC) were measured in plasma samples, lactate levels were determined in capillary blood samples, and serum lipid profiles were assessed. During restitution, plasma TAC was significantly higher (p < .05) in the supplemented group than in the placebo group. Serum total cholesterol levels at the end of the study were significantly (p < .05) lower in the supplemented group than in the placebo group. In conclusion, consuming artichoke-leaf extract, a natural vegetable preparation of high antioxidant potential, resulted in higher plasma TAC than placebo but did not limit oxidative damage to erythrocytes in competitive rowers subjected to strenuous training.