During sustained isometric contraction of the quadriceps, what distinguishes slow-twitch muscle fibers from fast-twitch muscle fibers regarding their response to reduced ATP availability?

💡 Explanation

Sustained contraction with depleted ATP leads to rigor in both fiber types. However, slow-twitch fibers are more susceptible to prolonged myosin head attachment and subsequent contracture because of their slower detachment rate when ATP is scarce; therefore, contracture is more likely, rather than faster glycogen depletion in these fibers.

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