Why it's on the list: Squats are king because they're the most challenging leg movement you can do. They work all the lower-body musculature and have been shown to spike muscle-building hormone release. In fact, squatting before doing curls has even been shown to significantly improve arm strength! Don't laugh: Powerlifter and bodybuilder Layne Norton, Ph.D., pairs the two moves in his Legs and Arms Blast workout.
High bar or low bar? That's up to you and your goals. High bar, where the bar rests atop the traps, hits all the leg musculature fairly evenly. Low bar, a favorite of powerlifters, targets the glutes and allows you to lift more weight. Not sure which? Choose the variation that allows you to squat deeper, more comfortably, and without excessively rounding your back.
Back Squat Variations for Leg Development:
In your workout: For leg growth, do this movement first with several light warm-up sets, pyramiding up in weight, before attempting your heaviest weight for multiple sets. Classic rep schemes like 5x5 or 3x8-10 work great. Don't be afraid to belt up if you're going heavy.