Answer: A) require maximal contraction of muscles for short periods of time.
Explanation:
During intense and prolonged physical exercise, fatigue is mainly related to hypoglycemia, since both glucose and carbohydrate oxidation ratio decrease. A widely accepted hypothesis to explain peripheral fatigue involves energy deficiency for muscle work, also known as the "Glycogen Depletion Hypothesis."
The energy from our diet is stored in the ATP (adenosine triphosphate) molecules. This represents the potential energy reservoir that can be used in the body's various biological work requiring energy, such as muscle contraction in mechanical muscle contraction work, breakdown of ATP into ADP (adenosine diphosphate), and its phosphorylation. ATP constitutes the so-called ATP-ADP cycle.
ATP formation occurs mainly through aerobic (oxidative) processes, but also during high intensity (anaerobic) exercises with a consequent lactate formation and phosphocreatine breakdown.
