Chapter 1-3: In Chapter 1-3, you learned about the structure and function of exercising muscle, the metabolic processes to generate ATP, and the neurological control of the body. Describe the relationship between muscle force development and the recruitment of type I and type II motor units, the differentiation between type I and type II in relation to ATP generation via the three energy systems, and the roles that muscle spindle and Golgi tendon organ have in controlling muscle contraction.