Table 1.

Characteristics of muscle fiber types.

	Type I Slow oxidative	Type II Fast oxidative	Type IIx Fast glycolitic
Contraction	Slow-twitch	Fast-twitch	Fast-twitch
Fiber size	Small	Intermediate	Large
Myoglobin concentration	High	High	Low
Capillary density	High	High	Low
Color	Red	Red	White
Mitochondrial content	High	High	Low
Fatigue resistance	High	High	Low
Major storage fuel	Triglycerides	Creatinine-Phosphate and Glycogen	Creatinine-Phosphate and Glycogen
Activity used for	Aerobic	Long-term	Short-term anaerobic