The American Council on Exercise is proud to introduce The Exercise Professional's Guide to Group Fitness Instruction. This textbook teaches the instructional techniques, leadership skills, and professional responsibilities that instructors need to lead safe, effective, and enjoyable group fitness classes. In response to an evolving fitness industry, this textbook addresses teaching classes in environments outside the traditional fitness facility, from outdoors to online. In addition to offering cueing and leadership strategies specific to these environments, this text includes coverage of legal considerations that are vital to the success of the ACE Certified Group Fitness Instructor (GFI), such as shared-use agreements to ensure that you are using public land in a safe and legal way and considerations for the proper, legal use of music when livestreaming classes or offering prerecorded sessions. In addition, features are included throughout--including Apply What You Know, Think It Through, Expand Your Knowledge, and the ACE Mover Method™--that bring theoretical concepts to life and ask you to pause to gauge your understanding of the topic being discussed, as well as your comfort level with utilizing that knowledge when teaching classes. We encourage you to take advantage of these application-based tools so that you will be better prepared to thrive in real-world situations. GFIs can apply the ACE Mover Method--a behavior-change philosophy that centers on the needs, goals, and values of participants--both before and after class using the ACE ABC Approach™ when privately engaging with participants. This textbook introduces the ACE RRAMP Approach™, on the other hand, as a unique way to implement the ACE Mover Method by engaging with participants as a group while leading a group fitness class. The ultimate goal is to use these approaches and other behavior-change strategies to create a caring and task-involving environment that allows participants to progress through the stages of learning and experience the intended outcome of the class while also having a positive experience. This textbook is organized into four sections: Section I: Group Fitness Fundamentals explains the role and scope of practice of the GFI, exercise and behavior-change principles, and the foundations of movement and healthy eating. Section II: Preparation and Design for Group Fitness Classes explains choreographic methods and the basic components of a group fitness class; key considerations regarding apparel, equipment, and music; program design, including structuring and sequencing movements and developing a class blueprint; and onsite procedures and responsibilities. Section III: Elements of Leading Group Fitness Classes focuses on participant-centered instruction, including participant learning styles and the teaching of multilevel classes; teaching techniques and styles, including cueing strategies and leadership considerations; the specific considerations stemming from teaching classes outdoors and online; and working with participants with health considerations ranging from cardiac conditions to low-back pain. Section IV: Professional and Legal Considerations covers participant safety, including injuries and medical emergencies, as well as the legal and professional guidelines that all GFIs must consider. Finally, in response to cultural shifts both inside the fitness industry and in the world at large, this textbook emphasizes the importance of equity, diversity, and inclusion (EDI). In addition to features explaining the current state of the fitness industry and how you as a GFI can help the industry move forward in a more inclusive way, EDI considerations are included throughout in the context of participant motivation and adherence, as well as the ability of the GFI to provide a welcoming and empowering climate for all participants. Along with serving as a study aid for the ACE Group Fitness Instructor Certification Exam, The Exercise Professional's Guide to Group Fitness Instruction is a valuable resource for both new and veteran instructors that not only provides the critical knowledge you will need to effectively lead a class, but also application-based tools to help you master that content and then utilize it to create memorable movement experiences and empower your participants through person-centered instruction and behavior-change strategies.