Fiber type refers to the classification of muscle fibers based on their characteristics and functions. There are primarily three types: Type I fibers, also known as slow-twitch fibers, are endurance-oriented and resistant to fatigue. They are ideal for activities like long-distance running and cycling. Type II fibers, or fast-twitch fibers, are further divided into Type IIa and Type IIb. Type IIa fibers are more versatile, supporting both endurance and strength, while Type IIb fibers are geared towards explosive power and quick bursts of activity, making them suitable for sprinting and weightlifting.