performing activities that require endurance, such as long-distance running or cycling. These muscle fibers are designed to contract and sustain force over extended periods of time, making them highly resistant to fatigue. Slow twitch muscle fibers rely primarily on the aerobic energy system, which uses oxygen to convert stored carbohydrates and fats into energy. They are rich in mitochondria, which are responsible for producing energy in the form of adenosine triphosphate (ATP). Additionally, slow twitch muscle fibers have a greater capacity to store oxygen and have a high number of capillaries, allowing for efficient oxygen delivery to the muscles.
