Exercise biomarkers

This chapter explores the diverse range of biomarkers associated with endurance exercise and their relevance for monitoring training adaptation, physiological stress, recovery, and long-term health. Covering cardiovascular (CV), metabolic, hormonal, inflammatory, and neuromodulatory systems, these markers offer valuable insights into how physical activity (PA) affects systemic function. CV parameters such as resting heart rate, heart rate variability, blood pressure (BP), pulse wave velocity, and VO₂max are well-established indicators of fitness and autonomic regulation. Emerging indicators like oxidative stress markers, PGC-1α, and microRNAs provide a window into mitochondrial function and cellular adaptation. Neuromodulators including β-endorphins, endocannabinoids, dopamine, serotonin, and BDNF are discussed in relation to the phenomenon known as the Runner's High, illustrating how endurance exercise can influence mood, perception, and pain sensitivity. The chapter also addresses challenges such as interindividual variability, sampling timing, and practical application. Together, these biomarkers form an integrative framework for evaluating endurance training, optimizing performance, and supporting preventive health strategies across clinical and athletic populations.