• Start to get in a pushup position, hands firmly on the floor, slightly wider than shoulder-width apart.
• Bend your elbows slightly and shift your weight onto your forearms. Your body should form a straight line from your shoulders to your ankles.
• Squeeze your abs, lift one foot off the floor and bring your knee up towards your chest while keeping your body in as straight as possible. Return to the starting position and repeat the movement with your opposite leg.
• Continue alternating and repeat the movement as fast as you can, while maintaining proper form.
• You should have one foot on the floor at all times to serve as your base.
• Don't lift your hips too high. Your body should form a straight line from your shoulders to your ankles.
• Don't arch your lower back. Tighten your abs to maintain a neutral spine.
You should feel your:
• Abs, oblique, shoulders.