MicroRNAs (miRNA) are small non-coding RNA molecules that regulate gene expression post-transcriptionally. Evidence indicating miRNAs influence exercise-induced health and performance adaptations is mounting. Circulating microRNAs are responsible for intercellular communication and could serve as biomarkers for disease and exercise-related traits. Such biomarkers would contribute to exercise screening, monitoring and the development of personalised exercise prescription. Accordingly, we investigated the impact of long-term strenuous aerobic exercise training and a single bout of maximal aerobic exercise on five muscle-enriched miRNAs implicated in exercise adaptations (miR-1, miR-133a, miR-181a, miR-486 and miR-494). We also determined linear correlations between miRNAs, resting heart rate and maximal oxygen uptake (V ̇O2max).We used TaqMan assay quantitative PCR to analyse the abundance of miR-1, miR-133a, miR-181a, miR-486 and miR-494 in resting whole blood of 67 endurance athletes and 61 healthy controls. Relative to controls, endurance athletes exhibited increased miR-1, miR-486 and miR-494 content (1.26–1.58-fold change, all p