You may feel a little sheepish when you start doing donkey kickbacks—but trust us, you won't regret this move. Not only does it torch calories, it also strengthens your core and glutes. Watch Health's contributing fitness editor, Kristin McGee, demonstrate how to kick your way to a tighter tummy and toned butt.
Here’s how to do it: Come onto all fours and tuck your toes. With your back neutral, scoop your abdominals and lift both knees about 2 inches off the ground. Bright your right knee in, then kick it straight out behind you. Repeat 8 times; switch legs and repeat.
Trainer tip: When you contract your abs, your knees should almost float off the floor, pulled up by the strength of your core.