Explain how muscle fibers are recruited in a movement with varying force demands. What are the advantages of the fibers being recruited in this manner?

2. Diagram, label and explain the components of a muscle fiber

1. When cross-bridge binding occurs, actin and myosin shorten and the muscle contracts. True False

32. After a 3-month period of long slow distance (LSD) training, muscle fiber mitochondria     decrease in number but increase in size     increase in number only     increase in size and number     increase in number but decrease in size