I am of the opinion that anyone who can squat 400 lb below parallel without a suit or press200 overhead has a strong core. I am of the opinion that when a person increases their squat, theyhave increased their core strength. I am also of the opinion that if a person wants to strengthentheir core, they must make something quantifiably stronger.
Mark RippetoeThere is never an absolute answer to everything, except of course that you have to do your squats.
Mark RippetoeStart training yourself. You don't have to have been an elite lifter to be a good coach - I sure as hell wasn't. But you have to at least have been under the bar enough to know why wedon't look up at the bleeding ceiling when we squat!
Mark RippetoeThere is simply no other exercise, and certainly no machine, that produces the level of central nervous system activity, improved balance and coordination, skeletal loading and bone density enhancement, muscular stimulation and growth, connective tissue stress and strength, psychological demand and toughness, and overall systemic conditioning than the correctly performed full squat.
Mark Rippetoe