If a weightlifter experiences rapid muscle fatigue during a set, which mechanism best explains why continued exertion becomes impossible despite neurological drive?

💡 Explanation

Muscle fatigue occurs with intense exertion as glycolysis generates lactate, acidifying the muscle cells. This pH drop interferes with actin-myosin cross-bridge cycling because the acidic environment alters protein conformation and binding affinity, thereby reducing force production. Therefore, fatigue sets in because the low pH prevents sustained contraction, rather than other mechanisms that maintain energy supply or oxygen delivery.

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