Chapter 6, Problem 36CT

When Eric returned from jogging, he was breathing heavily and sweating profusely, and he complained that his legs ached and felt weak. On the basis of what you have learned about muscle energy metab-olism, respond to the following questions:

a. Why is Eric breathing heavily?

b. What ATP-harvesting pathway have his working muscles been using that leads to such a breathing pattern?

c. What metabolic product(s) might account for his sore muscles and his feeling of muscle weakness?