Final answer:
Fast-twitch muscle fibers refer to the type of skeletal muscle cells that are mainly responsible for anaerobic activities like weight lifting. They can contract quickly and with a greater amount of force, making them ideal for performing fast actions.
Step-by-step explanation:
Fast-twitch muscle fibers refer to the type of skeletal muscle cells that are mainly responsible for anaerobic activities like weight lifting. These muscle fibers can contract more quickly and with a greater amount of force than slow-twitch fibers, making them ideal for performing fast actions. Fast-twitch muscle fibers consume small amounts of oxygen and primarily produce ATP through anaerobic glycolysis, allowing them to sustain short bursts of activity.