The metabolic pathways utilized by these fibers also differ:
- Type I fibers: Rely primarily on oxidative phosphorylation, a process that uses oxygen to produce ATP. This makes them highly efficient for prolonged, low-intensity activities. - Type II fibers: Primarily use anaerobic glycolysis for ATP production, allowing for quick energy release but resulting in faster fatigue. Type IIa fibers can also utilize oxidative phosphorylation to a lesser extent.
