Which type of muscle fibers are known for speed and power?

Fast-twitch fibers are specialized muscle fibers designed for explosive movements, making them ideal for activities that require speed and power. These fibers contract quickly and produce a large amount of force, which is essential in sports and activities involving short bursts of intense effort, such as sprinting, weightlifting, and jumping.

Fast-twitch fibers, also known as Type II fibers, rely more on anaerobic metabolism, enabling them to generate energy quickly but also causing fatigue at a faster rate compared to slow-twitch fibers. Their structure allows for a greater cross-sectional area, leading to increased muscle power output.

In contrast, slow-twitch fibers are geared towards endurance activities and are more efficient in using oxygen to generate energy over extended periods, making them more suited for long-distance running or cycling. Intermediate fibers possess characteristics of both slow and fast-twitch fibers and provide a good mix of endurance and power but do not excel in either extreme. Hybrid fibers, while less commonly referenced, typically indicate a blend of both types but do not specifically denote the high-speed, high-power attributes associated with fast-twitch fibers.