Stand on your left leg, holding a 5- to 15-pound kettlebell or dumbbell in your left hand, and lift your right knee straight up. Lunge directly to your right, keeping your right knee directly above your foot and extending straight down in front of you. For perfect form, extend your booty and keep your left leg straight the entire time. Firmly push off your right foot to return to starting position, then repeat 15 times. Complete 15 reps on each side.