The quads are the most feared muscles to train since it often takes all the grit and guts available.
For quad gains, there is nothing better than absolute annihilation. Here is a quick workout that will leave you walking a little weird for a few days.
A1 Front squats Barbell x8 tempo 4010
A2 Back squats barbell x 10 tempo 4010
A3 Barbell cyclist squats x 12 tempo 3010
A4 Leg extension x15 tempo 3020
A5 Leg press x 25 tempo 2020
A6 walking lunges x10 each leg
4 sets with 120 seconds of rest after each circuits.
All exercises are to be done consecutively with as little rest in between as possible. If you choose the correct weight, you will probably have to cut the weight by 15-20% every following sets.