Oxygen

Maximal aerobic power (V̇O₂peak) in youth depends on hemoglobin (Hb)—mediated oxygen transport. While sex- and age-specific patterns are established in untrained cohorts, further research is needed in competitive adolescent athletes. We studied 124 young athletes matched by age and sex (62 boys, 62 girls; 10–16 years). Hb was measured from fasting blood samples, and V̇O₂peak was determined via cardiopulmonary exercise testing (CPET). Boys showed higher Hb than girls (14.43 ± 0.85 g/dL vs. 13.6 ± 0.74 g/dL; p < 0.001) and a significant age-related increase (B = 0.29, p < 0.001), whereas girls remained stable. V̇O₂peak was also higher in boys (50.03 ± 6.18 mL/min/kg, p < 0.001). Regression analysis identified Hb as a strong predictor of V̇O₂peak (β = 0.40, p < 0.001). These findings demonstrate that classical developmental Hb trajectories persist in highly trained youth and confirm Hb as a key determinant of aerobic power. Monitoring hematological status, particularly in female athletes, is essential for optimizing performance and development.

Root pruning has been proposed as a practical method to regulate growth and metabolite accumulation in horticultural crops, yet its physiological and metabolic consequences in hydroponically grown lettuce remain poorly understood. In this study, we examined the effects of root pruning, applied two days before harvest, on biomass production, oxidative stress responses, and metabolite accumulation in red leaf lettuce. Root pruning suppressed root growth and reduced root water content in a severity-dependent manner. Shoot fresh weight also declined, whereas shoot dry weight was significantly reduced only under severe pruning. Young leaves of pruned plants exhibited transient reddish coloration, which was most pronounced under severe pruning. Quantitative analyses revealed that anthocyanin content increased up to 4.5-fold compared with the control, while total phenolic content also rose significantly. These metabolic changes were accompanied by pronounced oxidative stress, as indicated by elevated hydrogen peroxide accumulation and enhanced lipid peroxidation. In addition, leaf nitrate concentration decreased significantly in both moderate and severe pruning treatments. Collectively, these findings demonstrate that root pruning acts as a controllable stressor that triggers oxidative stress signaling, enhances antioxidant metabolite accumulation, and reduces nitrate content, highlighting its potential as a pre-harvest strategy for improving the nutritional and functional quality of hydroponic lettuce.

This review indicates that microalgae may serve as a sustainable supply of bioactive compounds and lipids over the long run. It also discusses the significance of lactic acid bacteria (LAB) and Saccharomyces cerevisiae in biotransformation processes. Microalgae contribute to food security and environmental sustainability due to their rapid growth and diverse applications, including food, feed, and biofuels. Fermentation with LAB and S. cerevisiae enhances the nutritional and functional properties of microalgal biomass, rendering it more digestible, bioactive, and palatable. This review discusses the metabolic characteristics of LAB and S. cerevisiae, their ability to modify microalgal components through enzymatic action, and the resultant products, including enhanced fatty acid profiles and bioactive compounds. Furthermore, the biotransformation of pigments during LAB fermentation is examined, revealing significant alterations in the hue and bioactivity of the pigments, hence enhancing the appeal of microalgal products. Future perspectives emphasize the necessity for further investigation to identify optimal fermentation conditions and to explore the synergistic interactions between LAB and S. cerevisiae in the production of novel beneficial components from microalgae using both microbes.