Sit-Ups, Crunches, Planks, Knee-Ups: The Evolution of Core Fitness

Core strength testing has come a long way from the straight-legged, twisting sit-ups used before World War II.

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What is the difference between sit-ups and crunches? Which one is better for abs? Which one is easier to perform and which one gives faster results for those who are new in

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ACE - ProSource™: February 2014 - Reality Check: Are Planks Really the Best Core Exercise?

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Sit-Ups, Crunches, Planks, Knee-Ups: The Evolution of Core Fitness Testing