34.1 The Endocrine System
34.2 Glands of the Endocrine System
34.3 The Reproductive System
34.4 Fertilization and Development
OUT OF STRIDE
Lisa trained hard during spring track and over the summer. But as the new school year approached, she wasn't satisfied. For her cross-country team to win the state championship, she felt that she needed to be faster. A teammate suggested she lose a few pounds. Lisa had already lost weight over the summer, but she decided to lose some more.
In addition to her strenuous workouts, Lisa stopped snacking before practice and avoided high-calorie foods. She did lose weight. But she was always tired. She also noticed that she had not had a menstrual period in four months. The week before the championship meet, she collapsed in pain at practice. She had suffered a stress fracture to her lower leg. Her season was over.
Lisa's doctor told her that all of her symptoms were related. As you read this chapter, look for clues to explain why excessive exercise and dieting had these effects on Lisa. Then, solve the mystery.
Never Stop Exploring Your World.
Finding the solution to the Out of Stride mystery is just the beginning. Take a video field trip with the ecogeeks of Untamed Science to see where the mystery leads.