To use squats as part of a HIIT program, you need to understand why they are done and how to perform them. Squats are foundational moves because they are part of everyday activities in which body weight is evenly distributed through both feet (e.g., bending down to pick something up off the floor, lowering into a chair or onto a toilet seat). Additionally, because squats require a significant contribution of lower-body muscle and joint action, they can use a lot of energy. Therefore, a variety of squats are presented in The HIIT Advantage to help you achieve appropriate overload in your HIIT workouts.