Final answer:
True, endurance exercises majorly involve slow-twitch muscle fibers, which are equipped with higher levels of myoglobin and mitochondria that allow them to sustain contractions for longer periods than fast-twitch fibers.
Step-by-step explanation:
Endurance exercises primarily utilize slow-twitch muscle fibers, making the statement true. These fibers are designed for activities that require sustained effort over long periods.
Slow-twitch fibers are characterized by a high content of myoglobin, an abundance of mitochondria, and they contract for extended periods due to their efficient aerobic metabolism.
These features make them ideally suited for endurance events such as distance running and cycling. Endurance athletes, like marathon runners, tend to have a higher proportion of slow-twitch fibers which enhances their ability to maintain activity over time. In contrast, fast-twitch muscle fibers are built for short, powerful bursts of activity and fatigue quickly.