Force produced by Type 2b fibres is high.

Force produced by Type 2b fibres is high.

• A. Low
• B. Medium
• C. None
• D. High

Answer: (D)

Fast-twitch glycolytic fibres (Type IIb) are built for high-speed, high-power contractions. Their large diameter and high myosin ATPase activity enable rapid cross-bridge cycling, so they can generate a large amount of force quickly. They’re activated for short, explosive actions like sprinting or heavy lifting and rely mainly on anaerobic metabolism, which supports rapid force production but drains energy stores quickly. This combination means their peak force output is high, even though they tire easily, which is why the correct description is that they produce high force.

Fast-twitch glycolytic fibres (Type IIb) are built for high-speed, high-power contractions. Their large diameter and high myosin ATPase activity enable rapid cross-bridge cycling, so they can generate a large amount of force quickly. They’re activated for short, explosive actions like sprinting or heavy lifting and rely mainly on anaerobic metabolism, which supports rapid force production but drains energy stores quickly. This combination means their peak force output is high, even though they tire easily, which is why the correct description is that they produce high force.