Question

multiple choice question

in high-intensity short-duration exercise, what does muscle fatigue result from?

increased atp
increased potassium
increased glycogen
increased oxygen

Explanation:

Analyze the physiological changes during short-duration high-intensity exercise

Using the Muscle Metabolism knowledge point
During short-duration, high-intensity exercise, rapid action potential propagation along the sarcolemma and down the T-tubules causes a massive efflux of potassium ions (\(\text{K}^+\)) from the sarcoplasm into the extracellular fluid (interstitial space of the T-tubules). This accumulation of extracellular potassium alters the membrane potential, reducing the excitability of the muscle fiber and contributing directly to muscle fatigue.

Evaluate the incorrect options

• Increased ATP: High-intensity exercise depletes ATP and phosphocreatine stores; ATP levels do not increase.
• Increased glycogen: Glycogen is rapidly broken down (glycogenolysis) to fuel glycolysis, so glycogen levels decrease rather than increase.
• Increased oxygen: High-intensity short-duration exercise relies primarily on anaerobic pathways, and oxygen delivery does not increase sufficiently to meet the immediate demand, nor does tissue oxygen concentration rise.

Answer:

• Increased ATP
• Increased potassium (Correct answer)
• Increased glycogen
• Increased oxygen