Metabolite signatures of exercise training in human skeletal muscle relate to mitochondrial remodelling and cardiometabolic fitness

ims/hypothesis Targeted metabolomic and transcriptomic approaches were used to evaluate the relationship between skeletal muscle metabolite signatures, gene expression profiles and clinical outcomes in response to various exercise training interventions. We hypothesised that changes in mitochondrial metabolic intermediates would predict improvements in clinical risk factors, thereby offering novel insights into potential mechanisms. Methods Subjects at risk of metabolic disease were randomised to 6 months of inactivity or one of five aerobic and/or resistance training programmes ( n = 112). Pre/post-intervention assessments included cardiorespiratory fitness ( ·VO_2peak ), serum triacylglycerols (TGs) and insulin sensitivity (S I ). In this secondary analysis, muscle biopsy specimens were used for targeted mass spectrometry-based analysis of metabolic intermediates and measurement of mRNA expression of genes involved in metabolism. Results Exercise regimens with the largest energy expenditure produced robust increases in muscle concentrations of even-chain acylcarnitines (median 37–488