If a muscle biopsy of a marathon runner reveals elevated intracellular lactate levels immediately after finishing a race, which consequence follows regarding muscle fiber function?

💡 Explanation

Elevated lactate implies anaerobic metabolism and resultant acidosis within muscle fibers. This increased acidity inhibits optimal cross-bridge cycling because it interferes with calcium binding to troponin and disrupts protein folding; therefore, force production decreases at a given stimulation level, rather than increasing calcium binding or ATP hydrolysis. Lactate accumulation inhibits glycogen synthesis, rather than enhancing it.

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