Type I muscle fibers

Type I muscle fibers, also known as slow-twitch fibers, are specialized for endurance and sustained activity. They have a high density of mitochondria, allowing them to efficiently produce energy through oxygen-based (aerobic) metabolism. These fibers are highly resistant to fatigue, making them ideal for activities like long-distance running, cycling, or maintaining posture. They contract more slowly and generate less force compared to other fibers but can work for extended periods without tiring. Their endurance qualities are vital for activities requiring prolonged, steady effort.