This document outlines the learning objectives and content for a unit on the effects of exercise on the body's systems. It describes both the short-term and long-term impacts of exercise on the musculoskeletal, cardiovascular and respiratory systems. Specifically, it addresses how exercise acutely affects heart rate, breathing, and muscle fibers, while chronic exercise leads to increased bone and muscle strength over time. It also discusses the energy systems used in different physical activities and sports, as well as the performance-enhancing drugs used illegally and their health risks.