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. C Show more
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. Show less
The global rise in mental health conditions has prompted interest in interventions that act beyond conventional psychopharmacology. Psychobiotics, broadly understood as live microorganisms or microbe- Show more
The global rise in mental health conditions has prompted interest in interventions that act beyond conventional psychopharmacology. Psychobiotics, broadly understood as live microorganisms or microbe-derived products that interact with the microbiota-gut-brain axis, have been suggested to exert neuroactive effects through neural, immune, endocrine and metabolic routes. This narrative review synthesizes recent preclinical, mechanistic and early clinical observations. Experimental studies show that selected strains can modulate cytokine signalling, influence stress-responsive systems such as the hypothalamic-pituitary-adrenal axis, and support synaptic plasticity via factors such as brain-derived neurotrophic factor. A limited number of human trials using well-characterized Lactobacillus and Bifidobacterium strains have reported improvements in affective and stress-related outcomes, but these effects are generally small to moderate, more apparent in adjunctive than stand-alone use, and dependent on strain, dose, population and intervention length (typically 4-12 weeks). Evidence on neurodevelopmental conditions (e.g., autism spectrum disorder, attention-deficit/hyperactivity disorder) remains preliminary, based on small and heterogeneous samples. Across studies, key constraints include methodological heterogeneity, incomplete strain-level reporting, and gaps in mechanistic resolution that make it difficult to link microbial shifts to psychiatric benefit. Emerging microbiome- and metabolomics-informed approaches may help identify likely responders and improve translational precision, but they are not yet ready for routine clinical application. Overall, psychobiotics should currently be viewed as a promising adjunct within integrative mental health care, warranting larger, standardized trials with clearly defined strains, doses and mechanistic endpoints. Show less