I just watched your episode on squats with a smith machine. I noticed you just went to parallel, whereas, in crossfit, the squat is below parallel. I was told by crossfit coaches that you are to squat below parallel, because it's more beneficial and the intended way people are to squat ( ie kids squat below parallel).  Is there any truth to this? 

Yes and no. The quads are in fact activated slightly more if you go “ass to grass”, but in irder to do these squats form must be altered with a wider than normal stance and toes pointed outward more which puts a greater load onto the vastus media list and rictus femoris. However, there is a posterior tilt which occurs in the hips as you go all the way down. Next time you observe someone squat watch how their butt rotates inward at the bottom. This can cause a slight separation in the lower lumbar spine which increases the risk of injury. Going parallel to where the thigh is parallel is the agreed depth and most beneficial depth in most strength and conditioning facilities. There are no studies that show a huge increase or benefit from going parallel , vs. ass to grass. The problem I have with crossfit, is you have uneducated “coaches” who have little to no knowledge or education outside of their experience in a crossfit setting. Yes, cleans, squats and deadlifts are the staples which are the best movements you can do, however these lifts should truly not be timed or used in a setting to where form is compromised because you are attempting to do as many reps as you can do. Most of these movements most strength coaches would advise to stay within a lower rep range unless you are doing much lighter weight where you can focus on form and technique. This is one reason why so many become injured in crossfit. There are some good boxes out there, but remember there is no one way to lift that is the absolute. Anyone who says so, has absolutely no idea what they are talking about and should not be looked to as an expert.