by Mark Rippetoe Starting Strength
Depends on why you’re squatting. If you are squatting to get as much muscle mass as strong as possible over the longest effective range of motion, you sure can squat too deep. Here’s why:
Strong means the production of force against an external resistance. Using as much muscle mass as possible enables the production of more force, since more contractile machinery is engaged in the production of that force. But it’s possible to squat huge weights if you can get the federation to ignore your depth – we won’t ignore it. A squat should be just below parallel, with the hip crease just below the top of the superior aspect of the patella when viewed from the side.
There are two reasons for this. First, we have to have a performance standard that is fairly applicable to everybody, because without this it is impossible to quantify the performance. Everybody has hips and everybody has knees, and if everybody breaks parallel, we can compare performances from trainee to trainee, and from workout to workout, so we can compare the efforts. If 1 inch above is okay, it’s hard to tell the lifter that 1.5 is not, and pretty soon we’re all 8 inches high.
Second, we want to work as much muscle mass as possible, and some of that muscle mass doesn’t work until the bottom of the range of motion is involved. Exactly how much of the posterior chain is working at half-squat depth vs. full-squat depth isn’t really interesting – what’s interesting is that a rebound occurs at a point somewhere in the vicinity of just-below-parallel, and this stretch reflex tells us that the musculature that operates at a closed hip angle is engaged.
This fact combined with the quantification thing makes just-below-parallel a useful criterion for judging the squat. In fact, all the powerlifting federations use the same language in their rules, so down deep in their hearts they understand it too. They just don’t actually judge it that way.
We do. But we also understand that an overreaction to things like this:
should not be things like this:
An ass-to-grass squat requires the relaxation of the quads, calves, glutes, adductors, abs, and lumbar erectors for the vast majority of the human race. Hamstrings may not relax for some people, since as knees flex and slack the hamstrings distally, the hips are flexing and tensioning the hamstrings proximally. But 8 inches below parallel cannot be obtained with the same muscle belly lengths used in a below-parallel squat, and this plus the extra depth reduces the force production potential of the movement.
Back to the original question: why are you squatting? If you think that your squats should be a display of superior mobility, ATG is your baby. But if you are training for strength, 405 just below parallel is heavier and harder than 315 ATG. I recommend squatting the way that allows you to produce more force by training the most muscle mass over the longest effective range of motion.