Do This 4-Minute No-Equipment Workout to Flatten Abs and Shape Your Booty

Bring your heart rate up while you heat up your lower abs! This booty-blasting move requires a controlled core that'll help tone that hard-to-get lower belly area.

• Begin by standing with your feet hip-width apart.
• Make fists with both hands and bend the elbows to where your hands are about level with your chin.
• Drive the right knee up, twist your torso to the right, and bring the knee to meet your left elbow.
• Immediately repeat with the left knee meeting your right elbow, and do this in a hopping motion while staying on the balls of your feet.
• Keep your abdominal muscles engaged as your knees come up and squeeze the side oblique muscles as you twist.
• Continue for 60 seconds.