Metabolomics for Athlete Monitoring: An Evidence-Readiness Framework for Contextual Validation.

Metabolomics can place the metabolic consequences of training, competition, recovery, nutrition, and environmental exposure in a physiological context. However, an exercise-responsive metabolite should not be regarded as decision-ready on the basis of a pre-post association alone, because interpretation depends on the biological matrix, sampling time, analytical performance, athlete characteristics, and intended monitoring question. This structured narrative review examines the requirements for translating metabolomic findings into athlete monitoring. English-language, peer-reviewed studies were identified through structured searches of PubMed, Scopus, and Web of Science from 1 January 2020 through 31 July 2026. We distinguish source-evidence directness from validation maturity, which comprises discovery, analytical validation with independent replication, within-athlete longitudinal validation, and implementation testing against prespecified sport-relevant outcomes. We consider pathway-level interpretation of signals related to substrate use, recovery, and physiological stress, together with the metadata, repeated sampling, analytical quality control, and comparative testing required to establish value beyond established monitoring measures. Wearable biochemical sensing, continuous glucose monitoring, artificial intelligence, and multi-omics approaches may provide contextual information, but require analyte-specific calibration, transparent modeling, external validation, and demonstrated practical value. Metabolomics should therefore function as an explanatory layer in multimodal athlete monitoring while individual panels are evaluated in clearly defined sport and decision contexts.