Purpose: To really bring out the lower abs.
Execution: Grab the bar with an overhand grip slightly wider than shoulder width and allow yourself to hang fully with your arms extended (use straps if you find that your grip is giving out before your abs). With your knees bent at 90 degrees, contract your lower abs brining your legs all the way up and your knees right into your chest. Its ok to lean back slightly at the top of each rep. Make sure your spine curls at the bottom to fully engage the lower abs. Hold the top position for a squeeze while exhaling your breath. Every rep should equal a breath. Lower yourself in a slow controlled manner.