True or False: Slow twitch muscles primarily work aerobically.

Slow twitch muscles are primarily designed for endurance activities and are predominantly aerobic in their function. These muscle fibers have a high concentration of mitochondria, which are responsible for producing energy through the process of aerobic metabolism. This allows slow twitch fibers to efficiently use oxygen to generate ATP, the energy currency of the cell, over extended periods, making them ideal for activities such as long-distance running or cycling.

The primary characteristic of slow twitch fibers is their ability to sustain prolonged activity without fatigue, as they are capable of utilizing fat and carbohydrates in the presence of oxygen. This metabolism is more efficient for endurance rather than bursts of speed or high-intensity activities, which rely more on fast-twitch muscle fibers that engage anaerobically. Therefore, stating that slow twitch muscles primarily work aerobically is accurate.