Advances in electroanalytical detection of reactive oxygen species during intense physical exercise

Vigorous physical activity disrupts cellular redox homeostasis by increasing the production of reactive oxygen species (ROS), which act both as potential mediators of damage and as essential signals for exercise adaptation. This review summarizes current knowledge of the main ROS sources during high-intensity exercise and critically assesses electroanalytical strategies for monitoring their dynamics in vivo. We outline how mitochondrial electron leakage, NADPH oxidase activity and xanthine oxidase flux generate rapid, compartment-specific ROS bursts that are shaped by endogenous antioxidant networks. We then compare conventional indirect assays with emerging electrochemical approaches, highlighting how enzyme-modified microelectrodes, nanostructured redox interfaces and wearable electrochemical biosensors enable real-time, site-specific ROS quantification with improved sensitivity and selectivity. These advances have revealed new spatiotemporal patterns of ROS generation and helped clarify the dose–response relationship between exercise intensity, oxidative stress and redox signaling. Finally, we discuss translational opportunities and remaining challenges for electroanalytical ROS sensing in exercise science, including calibration in complex biological matrices, biofouling control and long-term stability in continuous monitoring formats.