The most important reason why muscles tire more quickly during high-intensity workouts than they do during low-intensity workouts is lack of available _____
A)lactate
B)glucose
C)glycogen
D)oxygen

Question

Quizplus · Accepted Answer

During high-intensity workouts, the demand for oxygen by the muscles exceeds the rate at which oxygen can be supplied through respiration and blood flow, leading to a lack of available oxygen and muscle fatigue. Lactate, glucose, and glycogen are all sources of energy for the muscles and are not directly related to oxygen availability.

The Most Important Reason Why Muscles Tire More Quickly During