I am now at the point where I have the knee aches. It takes me a lot longer to warm up. Almost every leg press i get on seems to aggravate them if I do the presses first. If I squat first, then leg press, I am ok as long as I go slow or if I wrap my knees. I LOVE the feel of heavy squats. The high rep stuff has taken some getting used to.
I do agree with whats been said here. Take a guy who does exclusively heavy weight, then throw him into some crazy high rep thing. You will have puke in no time. I recall trying a routine from Musclemag a long time ago. I squatted heavy, and just wanted a change. It was like this:
Take a weight you squat for 15, and a weight you leg curl for 15. You will do ONLY 12 reps for 3 sets on squats, resting 60 - 75 seconds between sets. Then you do the same for leg curls (3 sets). Wait 2 mins, then repeat.
I managed 4 rounds of this, and was on the floor of the gym for about 20 mins. Mid way through it, about the 2nd round or so of squats, when you start your squats the weight feels like its double for about 1 - 2 reps, then light, then fatigue kicks your ass and the weight doubles again. LOL.
Takes about 30 mins to do this workout. Never really felt much with other muscle groups like the article said (chest/back or bi/tri).