Changes in the blood redox balance during a simulated duathlon race and its relationship with athletic performance.

The duathlon is an endurance multisport event that consists of sequential running, cycling, and further running. Imbalance in the redox homeostasis is associated with fatigued status and underperformance in various sports; however, there are no corresponding reports regarding the duathlon. The purpose of this study was to examine the changes in the blood redox balance during a simulated duathlon race and to determine the relationship between performance and the redox balance. Eight male triathletes participated in a simulated race, consisting of a 5-km run, 30 km cycling, and a further 5-km run, with 5 min rest between two parts to collect the blood samples. The serum levels of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) were measured and BAP/d-ROMs ratio and oxidative stress index (OSI) were calculated. The d-ROMs levels after the first Run were significantly increased compared with the levels observed before the race. Moreover, BAP levels increased significantly over the race. The BAP/d-ROMs ratio also gradually increased through the race, while the OSI was gradually decreased. In addition, a significant relationship was observed only between d-ROMs levels after the first Run and the first Run performance. These results suggest that the redox balance shifts toward reduction (antioxidation) during the duathlon race and increased oxidant potential levels are negatively correlated with performance in the early stages of the race.

Can the elite slalom kayaker's performance be correlated with anthropometric, nutritional, genetic, psychological as sleep traits?

Abstract AIMS The aims of this study were to investigate and characterize the anthropometric, nutritional, genetic, psychological and sleep variables of slalom kayakers, and to verify the correlation of these variables with the slalom kayakers' performance. METHODS Ten elite Brazilian team slalom kayakers participated of this study. Nutritional analysis was made by the Food Record (three days), 24 Hour Dietary Recall and Food Frequency Questionnaire. The ACE I/D, AGTMet235Thr, ACTN3R577X and BDKRB2+9/-9 were genotyped for genetic profile. The Profile of Mood States (POMS) and Sports Competition Anxiety Test (SCAT) were applied to investigate the psychological variables. The Pittsburgh Sleep Quality Index (PSQI), Epworth Sleep Scale (ESS) and Morningness-eveningness questionnaire (MEQ) were used for sleep traits analysis. Performance trials were performed on a white-water course with 24 gates, and finish time was considered as the variable related to performance. RESULTS Significant correlations were obtained between Performance Time Trial and %Fat (r=0.77), Energy (r=-0.75), Protein (r=-0.76), Carbohydrate (r=-0.72), Vitamin B6 (r=-0.87), Vitamin A (r=-0.82), Thiamine (r=-0.77), Riboflavin (r=-0.71), Magnesium (r=-0.86) and Phosphorus (r=-0.74) intake, besides the Fatigue mood domain (r=0.73) and the SCAT score (r=0.67). Athletes genotyped with the I, T, R and +9 alelle also presented better performances. CONCLUSIONSIn summary, the novel results provided by this study reinforce the necessity of considering several aspects during athlete development in order to achieve better performance in competitions.