The hanging leg raise is a great ab workout, but many people don't perform it correctly. I see many people using momentum to swing their legs up, when you should be slowly contracting the abs to bring the straight legs up, hold for a few seconds then slowly lower again, everything in a controlled fashion.
This can be performed gripping the bar of a squat rack as I am doing here, or it can be performed with the padded straps that are made just for this purpose.
I prefer to grip the bar as I feel I can control my body better, and concentrate on a very tight core. It is difficult to do many of these at once, I superset them with reverse crunches. I will do 20 reverse crunches, then go straight to the rack, do 10 leg raises, and complete 4 sets of this without resting.
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