Russian Kettlebell Swings
A strong hip drive is what we’re working here, because that's how our body generates power. The glutes, hamstrings, and back are the predominate muscles involved in the hip drive, and the kettlebell swing is an effective tool for working those muscles. To do it, start with your feet shoulder-width apart, a kettlebell in front of you. Reach for the kettlebell, sending your hips down and back. Pull the kettlebell toward you, passing between your legs. Your wrists should graze your inner thighs and the kettlebell should be slightly behind you. With straight arms and a tight grip on the kettlebell, stand up tall and drive your hips forward until the bell reaches eye level. Make sure you keep a big gorilla chest and don’t round your back.
If you don't have a kettlebell, grab a dumbbell. Set the 'bell on its end, then grab the top end with two hands, like a burger. A tight grip and straight arms are especially important here.