i use squats as my main quad xercise and im just wondering how far down i should be going on the decent! i've seen alot of people go rite down below paralell, but for me i can only get to before paralell! ive used a board under my heels and this seems to let me go down further but with the xtra stress on my quads i feel the burn quicker and dont complete the same amount of reps as without the board! so how do u think i should be squatting? i squat 210 pounds!