No abstract

Hydrogen peroxide (H2O2) could induce oxidative damage at long distance from its generation site and it is also an important signalling molecule that induces some genes related to oxidative stress. Our objective was to study the plasma and blood cells capability to detoxify H2O2 after intense exercise and its correlation with oxidative damage. Blood samples were taken from nine professional cycling, participating in a mountain stage, under basal conditions and 3 h after the competition. Catalase and glutathione peroxidase activities decreased (40 and 50% respectively) in neutrophils after the cycling stage, while glutathione peroxidase increased (87%) in lymphocytes. Catalase protein levels and catalase specific activity maintained basal values after the stage in plasma. Catalase protein levels decreased (48%) in neutrophils and its specific activity increased up to plasma values after exercise. Myeloperoxidase (MPO) increased (39%) in neutrophils after the cycling stage. Exercise-induced hemolysis and lymphopenia inversely correlated with cellular markers of oxidative stress. Plasma malondialdehyde (MDA) directly correlated with neutrophil MPO activity and erythrocytes MDA. Intense exercise induces oxidative damage in blood cells as erythrocytes and lymphocytes, but not in neutrophils.

The purpose of the present study was to investigate the socio-demographic and lifestyle determinants of physical activity practice, as well as the motivations for being or not being physically active in Spanish university students. A representative sample of students from a Spanish university (n = 2,051; 42.1% males; mean age 21.9, s = 4.8 years) participated in the present cross-sectional study. A questionnaire including questions regarding lifestyle, dietary habits, parents' characteristics, and physical activity habits was administered to the students. The socio-demographic and lifestyle determinants of physical activity practice were assessed using multivariable logistic regression. 68.4% of men and 48.4% of women reported to practise physical activity in the present sample. Those who practised physical activity consumed more fruits and were less likely to be smokers compared to non-physically active students. Also, physically inactive men spent more time in front of the computer and physically inactive women spent more time in front of the TV and were more likely to be frequent alcohol consumers. Maternal educational level and maternal physical activity habits were also important determinants of physical activity practice among men and women respectively. In conclusion, physically active students tended to engage in other healthy habits in the present population, suggesting the clustering of healthy or unhealthy lifestyle factors among specific subgroups.