The purpose of this article is to provide an overview of how PE teachers can personalize learning to meet a variety of student needs. Differentiated instruction (DI) is a term frequently used in classroom-based learning to describe a method of personalization for individual students. The term can also describe a theoretical model for teaching and research, an instructional model, and a philosophy. Teachers must have a firm understanding of student readiness, interest, and learning profile to differentiate four areas of instruction: content, process, product, and the environment. Students in PE can benefit from DI, but there is a lack of formal methods to differentiate PE content. The Personalized System of Instruction (PSI) is an instructional model that provides a complete framework for PE teachers to personalize learning for all students. Fitness-related content such as resistance, plyometric, and agility training provides a context for applying the PSI model to DI in the secondary school setting.