Why do people who participate in marathons tend to have smaller muscles?

What hormones (at least three) are responsible for human growth and development and what do they do? describe what menstruation is and how it relates to reproduction. what are common emotional and physical challenges that arise during transition from child to adult? include and describe at least three challenges. what steps can you take to ease your own transition and be sensitive to others when they experience theirs? analyze the role of hormones in growth and development. how does this relate to your own personal health?