Certified Personal Trainer (NSCA) Practice Exam

Type II muscle fibers, also known as fast-twitch fibers, are primarily engaged during high-intensity, explosive activities. These fibers are characterized by their ability to generate quick, powerful bursts of strength and speed, making them well-suited for activities that require short-duration, high-velocity outputs.

In the context of athletic events, Olympic weightlifting requires significant power and strength, both of which are predominantly reliant on fast-twitch fibers. The movements in Olympic weightlifting, such as the clean and jerk or snatch, demand rapid acceleration and maximal force production, aligning perfectly with the capabilities of Type II muscle fibers.

Similarly, a 100m sprint involves a short burst of maximum effort, engaging fast-twitch fibers to generate the speed necessary to succeed in this highly competitive, quick-sprint race. The quick energy production and rapid muscle contractions inherent in sprinting mirror the strengths of Type II fibers.

Other options, such as a 10k road race and triathlon, tend to require sustained endurance, where slow-twitch (Type I) muscle fibers play a critical role due to their efficiency in using oxygen to produce energy for prolonged periods. Fast-twitch fibers, while they can contribute to performance in longer events, are not primarily