INCREASED OXIDATIVE STRESS BLOOD MARKERS IN WELL-TRAINED ROWERS FOLLOWING TWO THOUSAND-METER ROWING ERGOMETER RACE

Kyparos, A, Vrabas, IS, Nikolaidis, MG, Riganas, CS, and Kouretas, D. Increased oxidative stress blood markers in well-trained rowers following two thousand-meter rowing ergometer race. J Strength Cond Res 23(5): 1418-1426, 2009-High-intensity exercise is associated with increased oxidative stress. Rowing is very demanding requiring maintenance of high power mostly produced from aerobic metabolism. The present study aimed at investigating selective blood oxidative stress markers in response to a rowing race simulation test, consisting of 2,000 m maximal effort on a rowing ergometer, in well-trained male rowers during the preseason preparatory training period. Mean time for the 2,000-m trial was 409.4 +/- 4.0 seconds, and heart rate at 2,000 m was 198 +/- 1 b.min(-1) (mean +/- SEM). Blood lactate concentration was 11.2 +/- 0.6 mmol.L(-1). Postexercise whole blood lysate oxidized glutathione (GSSG) concentration significantly increased (19%), whereas reduced glutathione (GSH) concentration remained unchanged, resulting in an overall decreased postexercise GSH: GSSG ratio (20%). Postexercise serum thiobarbituric acid-reactive substance concentration and protein carbonyls increased by 45 and 70%, respectively, as compared with the pre-exercise levels. Likewise, postexercise catalase activity (105%) and total antioxidant capacity (9%) significantly increased. In agreement with other studies, our data illustrate that a 2,000-m rowing ergometer race induces significant blood oxidative stress despite the rowers' high training status. In scheduling an evaluation rowing test or a competition, coaches should allow sufficient recovery time elapsed between the test and the last intensive training session. The 2,000-m rowing performance appears to be a suitable test to assess oxidative stress in rowers and could potentially serve as a model to study oxidative damage in sports science

The effect of exercise-induced hypoxemia on blood redox status in well-trained rowers

Exercise-induced arterial hypoxemia (EIAH), characterized by decline in arterial oxyhemoglobin saturation (SaO2), is a common phenomenon in endurance athletes. Acute intensive exercise is associated with the generation of reactive species that may result in redox status disturbances and oxidation of cell macromolecules. The purpose of the present study was to investigate whether EIAH augments oxidative stress as determined in blood plasma and erythrocytes in well-trained male rowers after a 2,000-m rowing ergometer race. Initially, athletes were assigned into either the normoxemic (n = 9, SaO 2 [92%, V O2max: 62.0 ± 1.9 ml kg-1 min-1) or hypoxemic (n = 12, SaO2\92%, V O2max: 60.5 ± 2.2 ml kg-1 min-1, mean ± SEM) group, following an incremental V O2max test on a wind resistance braked rowing ergometer. On aseparate day the rowers performed a 2,000-m all-out effort on the same rowing ergometer. Following an overnight fast, blood samples were drawn from an antecubital vein before and immediately after the termination of the 2,000-mall-out effort and analyzed for selective oxidative stress markers. In both the normoxemic (SaO2: 94.1 ± 0.9%) and hypoxemic (SaO2: 88.6 ± 2.4%) rowers similar and significant exercise increase in serum thiobarbituric acidreactive substances, protein carbonyls, catalase and total antioxidant capacity concentration were observed post-2,000 m all-out effort. Exercise significantly increased the oxidized glutathione concentration and decreased the ratio of reduced (GSH)-to-oxidized (GSSG) glutathione in the normoxemic group only, whereas the reduced form of glutathione remained unaffected in either groups. The increased oxidation of GSH to GSSG in erythrocytes of normoxemic individuals suggest that erythrocyte redox status may be affected by the oxygen saturation degree of hemoglobin. Our findings indicate that exercise-induced hypoxemia did not further affect the increased blood oxidative damage of lipids and proteins observed after a2,000-m rowing ergometer race in highly-trained male rowers. The present data do not support any potential link between exercise-induced hypoxemia, oxidative stress increase and exercise performance. © 2011 Springer-Verlag

The effect of exercise-induced hypoxemia on blood redox status in well-trained rowers

Exercise-induced arterial hypoxemia (EIAH), characterized by decline in arterial oxyhemoglobin saturation (SaO(2)), is a common phenomenon in endurance athletes. Acute intensive exercise is associated with the generation of reactive species that may result in redox status disturbances and oxidation of cell macromolecules. The purpose of the present study was to investigate whether EIAH augments oxidative stress as determined in blood plasma and erythrocytes in well-trained male rowers after a 2,000-m rowing ergometer race. Initially, athletes were assigned into either the normoxemic ( = 9, SaO(2) > 92%, : 62.0 +/- A 1.9 ml kg(-1) min(-1)) or hypoxemic ( = 12, SaO(2) < 92%, : 60.5 +/- A 2.2 ml kg(-1) min(-1), mean +/- A SEM) group, following an incremental test on a wind resistance braked rowing ergometer. On a separate day the rowers performed a 2,000-m all-out effort on the same rowing ergometer. Following an overnight fast, blood samples were drawn from an antecubital vein before and immediately after the termination of the 2,000-m all-out effort and analyzed for selective oxidative stress markers. In both the normoxemic (SaO(2): 94.1 +/- A 0.9%) and hypoxemic (SaO(2): 88.6 +/- A 2.4%) rowers similar and significant exercise increase in serum thiobarbituric acid-reactive substances, protein carbonyls, catalase and total antioxidant capacity concentration were observed post-2,000 m all-out effort. Exercise significantly increased the oxidized glutathione concentration and decreased the ratio of reduced (GSH)-to-oxidized (GSSG) glutathione in the normoxemic group only, whereas the reduced form of glutathione remained unaffected in either groups. The increased oxidation of GSH to GSSG in erythrocytes of normoxemic individuals suggest that erythrocyte redox status may be affected by the oxygen saturation degree of hemoglobin. Our findings indicate that exercise-induced hypoxemia did not further affect the increased blood oxidative damage of lipids and proteins observed after a 2,000-m rowing ergometer race in highly-trained male rowers. The present data do not support any potential link between exercise-induced hypoxemia, oxidative stress increase and exercise performance