Slow-Twitch Fibers

Slow-twitch fibers, also known as Type I fibers, are a type of muscle fiber that contract slowly and are highly resistant to fatigue. They're designed for endurance activities, such as long-distance running or cycling, because they use oxygen efficiently to generate energy. This means they can sustain activity for extended periods without tiring quickly. Unlike fast-twitch fibers, which are better for short bursts of speed and power, slow-twitch fibers help support activities that require stamina and prolonged effort. Examples of muscles rich in slow-twitch fibers are those in the legs, which are used for endurance sports.