What type of muscle fiber is known as slow-twitch?

The term "slow-twitch" muscle fiber refers specifically to type I muscle fibers, which are primarily red muscle fibers. These fibers are characterized by a high content of myoglobin, which allows them to sustain prolonged periods of contraction and rely on aerobic metabolism for energy. This distinguishes them from fast-twitch fibers which are designed for short bursts of power and fatigue quickly.

Red muscle fibers are rich in capillaries and mitochondria, enabling them to efficiently use oxygen, making them ideal for endurance activities such as long-distance running or cycling. Their slow contraction speed and ability to generate less force for a longer duration make them essential for activities that require stamina.

In contrast to slow-twitch fibers, white muscle fibers, fast-twitch fibers, and certain types of skeletal muscle do not share the same endurance capabilities and metabolic characteristics. White muscle fibers are typically anaerobic and better suited for strength and power activities, whereas fast-twitch fibers refer specifically to type II fibers, which are distinct from the slow-twitch type I fibers. Skeletal muscle, on the whole, can include both slow-twitch and fast-twitch fibers, but it does not specifically denote the endurance-focused nature of slow-twitch fibers.

Thus, identifying red muscle fiber as the correct