Nothing beats properly performed squats, deadlifts, lunges, and RDLs for glutes that not only look great but work even better. Proper glute function is critical to hip extension that is prevalent in every day life (walking, sit to stand, hip hinge, lifting) as well as sport (running, sprinting, throwing, jumping, skating) Problem is most people don’t perform the big exercises well and therefore resort to ways to “activate” or better “isolate” glute function. This is why hip thrusts exist. They have their place when used with a plan and purpose. The single leg hip thrust is an advanced progression that is often performed incorrectly. The biggest mistake being the unleveling of the hips that can occur during the movement. By using the external cue of a tennis ball, we can promote better technique that results in improved muscular coordination of the glutes and core. This translates into more efficient movement mechanics, not only in this exercise, but in life and sport as well. Hopefully the video explains the set-up and execution well enough for you to give it a try.