Chapter 9.6, Problem 14CYU

When Eric returned from jogging, he was breathing heavily, sweating profusely, and complained that his legs ached and felt weak. His wife poured him a sports drink and urged him to take it easy until he could “catch his breath.” On the basis of what you have learned about muscle energy metabolism, respond to the following questions: Why is Eric breathing heavily? Which ATP-generating pathway have his working muscles been using that makes him breathless? What metabolic products might account for his sore muscles and muscle weakness?