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Knee hug crunches will build your abdominal muscles and strengthen your core. This is an advanced ab workout but if you can perform it properly it will build your abs fast.
Knee hug crunch exercise doesn't require weights or any equipment. You only need your own body and this means you can do the workout anywhere.
Learn how to do knee hug crunches correctly because mistakes can lead to lower back pain.
Combine this exercise with other ab exercises such as planks and hanging leg raises to build your core muscles fast.
Enjoy the knee hug crunches.