Figure 2

General hypothesis for convergent adaptation: endurance exercise versus resistance exercise in skeletal muscle. Skeletal muscle mitochondrial biogenesis is a form of “convergent adaptation” in response to endurance exercise, independent of p53, AMPKalpha and PGC-1alpha. Increased muscle mass and protein synthesis is a form of “convergent adaptation” in response to resistance exercise, independent of PTEN, IGF-1 and rapamycin. Endurance exercise increases gene expression selectively for mitochondrial proteins and enzymes and type I muscle fiber, resistance exercise increases gene expression selectively for muscle growth, anaerobic metabolism and type II muscle fiber. PGC-1α, peroxisome proliferator activated receptor-gamma coactivator 1 alpha; AMPKα, α subunit of AMP- activated kinase complex; PTEN, phosphatase and tensin homologue; IGF-1, insulin-like growth factor 1.