The key on the goblet squats is to elevate your heels and use a narrow stance to emphasize the quads. On the hack squats, do the opposite: use a high and wide stance. Don't come up all the way to ensure continuous tension. The weight is light but you'll do 6 rounds of this superset with 60 second rest breaks. The cumulative fatigue will begin to kick in by the third round!
Over the past few years I've seen many lifters and coaches discussing the seemingly strange movements I prescribe for strength development. Many of these guys are grasping the big picture but missing many of the finer points. To remedy this, I've written this "toolbox" series to help experienced lifters fill in the blanks and newer lifters learn about some very effective exercises.
I'll freely admit it. I've been extremely reluctant to sit down and write this article. Why? Well, the reasons are numerous, but it basically boils down to the pertinacity of the exercise community.