Tempo Front squats Strength

4x4 reps @ starting about 50% of 1 rm and go up as you feel.
Tempo is 31X1
3sec down, 1sec at bottom, explode up, 1 sec before starting new rep.
rest 2-2,5 min after each set. (perfect squats/control of weight)
Time limit 20minutes for squats including warm up sets.