This simple exercise activates and isolates the glutes, giving them a round, perky shape. It's normally performed on an exercise mat or from a standing position, depending on how much space you have available. The advantage is that you'll train one leg at a time, which allows you to better isolate the muscles worked. Moreover, unilateral training can facilitate injury rehab and help prevent muscle imbalances, per a Colorado State University blog post.
To get started, stand upright behind an office chair. Place your hands on it for support and brace your core. Next, take a deep breath, squeeze your glutes, and bring your right leg back. Lift your heel as high as you can without bending the leg. Keep your back straight and maintain a slight bend in your left knee. Hold the contraction for two or three seconds, bring your leg back down, and repeat with the same leg or the opposite leg. Complete three to four sets of 10 to 15 repetitions on each side.
The standing glute kickback may seem easy, but if you do it right, you'll really feel the burn. As you progress, wrap an elastic band around your thighs or ankles for added resistance. You can also do this exercise with a cable machine, which is a lot more challenging.