Adaptations to endurance training depend on exercise-induced oxidative stress: exploiting redox interindividual...

Area of Science:

• Physiology
• Exercise Science
• Redox Biology

Background:

• Reactive oxygen and nitrogen species (RONS) play a complex role in cellular signaling and adaptation.
• Understanding RONS's endogenous role in exercise adaptations is crucial for optimizing training and health outcomes.
• Previous studies often used exogenous agents, confounding the investigation of physiological RONS roles.

Purpose of the Study:

• To elucidate the role of endogenously produced RONS in exercise adaptations.
• To investigate physiological and redox adaptations to endurance training without external pro-oxidant or antioxidant interference.
• To establish the direct impact of exercise-induced oxidative stress levels on training outcomes.

Main Methods:

• Developed a novel methodology to stratify participants based on exercise-induced oxidative stress levels (low, moderate, high).
• Implemented a 6-week endurance training protocol.
• Assessed physiological adaptations (VO2 max, time trial, Wingate test) and redox biomarkers.

Main Results:

• The low oxidative stress group showed significantly lower improvements in endurance performance metrics compared to moderate and high oxidative stress groups.
• Adaptations in oxidative stress biomarkers and antioxidant levels were also diminished in the low oxidative stress group.
• This indicates a dose-dependent relationship between exercise-induced oxidative stress and training adaptations.

Conclusions:

• Substantiates the critical role of RONS generated during exercise in mediating physiological adaptations in humans.
• Demonstrates that exercise-induced oxidative stress, within physiological limits, is essential for maximizing training benefits.
• Proposes redox phenotyping as a valuable strategy for future research on RONS and antioxidant functions in biological systems.