Skeletal muscle undergoes fiber type metabolic switch without myosin heavy chain switch in response to defective fatty acid oxidation

•Fuel oxidation in glycolytic compared to oxidative muscles are different and intrinsic to the mitochondria.•Muscle CPT2 loss elicits fiber-type dependent mitochondrial biogenesis.•Muscle CPT2 loss elicits an oxidative-to-glycolytic shift in mitochondrial and metabolic properties.•Muscle CPT2 loss does not alter myosin heavy chain isoform composition.•CPT2 deficient muscles demonstrate a metabolic-contractile apparatus mismatch.