Post-Exercise Elevations in Organ Injury-Associated Biomarkers: Kinetics, Confounders, and Clinical Red Flags - A Narrative Review

Abstract

Background: Strenuous exercise can simultaneously alter muscle-, cardiac-, kidney-, liver-associated, inflammatory and haematological biomarkers. Values above population reference intervals may reflect exercise-related kinetics, concentration changes or pathology.

Aim: To synthesise post-exercise biomarker kinetics, major modifiers, preanalytical confounders and features distinguishing a transient response from findings requiring further evaluation.

Material and methods: This narrative review searched PubMed and Scopus for English-language publications from January 2008 to June 2026; Google Scholar and reference lists provided supplementary coverage. Evidence was appraised qualitatively and synthesised narratively without meta-analysis.

Results: CK, myoglobin, cardiac troponin, creatinine, urinary kidney biomarkers, AST, ALT, LDH and haemolysis-associated measures followed marker- and protocol-specific trajectories. Interpretation depended on exercise modality, dose and novelty, sampling time, hydration and plasma-volume shifts, baseline values, assay characteristics and serial direction. No isolated result reliably localised structural injury or provided a universal threshold or normalisation time. Symptoms, associated findings, persistence, worsening or patterns discordant with the exposure support urgent or targeted evaluation.

Conclusions: Exact sampling time and serial trajectory are more informative than isolated reference-interval crossing. Clinical and multibiomarker context is essential; short-term normalisation may support an exercise-related explanation but does not prove benignity or exclude transient structural change. The proposed checklist is conceptual and unvalidated. Standardised longitudinal studies are needed.