This document discusses the importance of understanding behavior change for personal trainers and outlines the 5 stages of behavior change. It explains that behavior change is one of the most difficult things to achieve and sustain. The 5 stages are: precontemplation, contemplation, preparation, action, and maintenance. Understanding behavior change can help trainers address client motivation issues, dropping out, or relapse. The stages provide guidance on how to support clients through small steps, overcoming barriers, and maintaining focus on long term goals.