3 sets of
15 heavy sumo dumbbell squats with 10 second hold at the bottom of the squat on 15th rep, immediately drop the weight to a medium weight and perform 15 reps with a 10 second hold at the bottom of the squat on 15th rep, immediately drop the weight to a light weight and perform 15 reps with a 10 second hold at the bottom of the squat on 15th rep. All this equals one set, each set is a total of 45 reps.
Note: Keep transition between weights fast and with no rest. Rest 2 minutes between sets.