Effects of Acute Aerobic Exercise on Skeletal Muscle Transcriptomics in Lean vs Overweight/Obese Men

Acute aerobic exercise has been shown to improve skeletal muscle mitochondrial function and completeness of fatty acid β-oxidation which contribute to improved insulin sensitivity. The effectiveness of acute exercise on improving mitochondrial adaptations, leading to improved insulin sensitivity, in overweight/obese (Ov/Ob) individuals is controversial. This study aimed to determine the effects of acute exercise on epigenetic regulation of genes involved in skeletal muscle mitochondrial adaptations in lean vs Ov/Ob men. 30 men, aged 19-30 years, were recruited and divided into two groups: lean (BMI<25, 18.5- 24.1 kg/m2, n=15) and Ov/Ob (BMI≥25, 25.5- 36.9 kg/m2, n=15). Vastus lateralis muscle biopsy samples were collected at rest, following an overnight fast (Pre; n=14 in lean Pre and n=15 in Ov/Ob Pre). Subjects then ingested a standardized high-carbohydrate breakfast (7 kcal/kg; 60% carbohydrate, 25% fat, 15% protein). Four hours later, they performed an acute bout of cycling exercise (50% VO2max, expending ~650 kcal) and vastus lateralis muscle biopsy samples were collected immediately after the exercise bout (Post; n=15 in lean Post and in Ov/Ob Post). RNA-seq via the Illumina platform was performed. Sequences were aligned using TopHat and differential gene expression determined using Cuffdiff.