SSS - Short Sharp Shock. 

1. Forced reps
2. Negatives
3. Triple drops
4. Rest-pause
5. Repetitions to total failure

1. Forced reps - these can be done on the hack squat or leg press with two individuals standing on either side of the machine. Just enough assistance is provided for two or more extra repetitions.
2. Negatives - these can be done on the leg press by way of improvisation with a "convenient" weight which allows you to pause completely at the bottom of the movement for one or two seconds under absolute control after which you can vary the speed at which you perform the upward thrust of the weight to the point of near lock out, where the weight is held still momentarily for another two seconds. Then lowered, still under strict control on the negative phase. This improvised movement can also be done on the leg extension machine. Alternatively, if you wanted to take things a step further, why not perform the negatives with a blindfold for added concentration and feel, which would obviously be accentuated directly as a result of the temporary inhibition of your powers of sight.
3. Triple Ds - this is straightforward and simple and can be performed on almost every leg machine. It involves loading up a machine with loose weights then getting two individuals to remove 10 to 15% of the weight as you engage continuously with a given set of repetitions.
4. Rest pause - all machines can again be adopted. Perform the required set of reps, rest for 15 seconds, repeat the exercise with the same weight for another 3 reps and rest again for another 15 seconds etc etc. Depending on your strength and stamina, you can perform 4 to 6 cycles of this sequence.

Points to Note:

1. SSS should be adopted only once every 6 weeks to avoid total burn out.
2. In addition to your normal training partner, there should be a third man to make this form of training practical.
3. It would be advisable not to have a heavy meal too close to training time.
4. Make sure your training environment is well ventilated.
5. Effective rep range for quad training is 12 to 15 reps.