Slow-twitch fibers

Slow-twitch fibers, or Type I fibers, are muscle fibers that contract slowly and are highly resistant to fatigue. They are rich in mitochondria and myoglobin, enabling efficient oxygen use for sustained aerobic activities. These fibers are crucial for endurance sports like marathon running, as they support prolonged, low-intensity efforts. Training can enhance their efficiency and endurance capacity. Runners with a higher proportion of slow-twitch fibers can maintain a steady pace longer, making them well-suited for long-distance events. Understanding fiber composition helps tailor training for optimal performance.