A weightlifter attempting a maximal lift experiences muscle fatigue and complete lift failure. Which mechanism most directly explains why the muscle fails to maintain force during the lift?

💡 Explanation

Muscle fatigue leading to lift failure arises primarily from inorganic phosphate accumulation within muscle cells, which directly inhibits the actomyosin cross-bridge cycle. Because the phosphate accumulation prevents effective force generation, therefore muscle contraction fails rather than from substrate depletion alone or neural factors.

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