Forced Reps Training System
Arnold describes forced reps as training past the point of failure. It is certainly not recommended that anyone try this technique if you have not been training for more than 6 months. It can be done on any movement but you need the help of a spotter or training partner who knows what they are doing.
To explain how forced reps are done correctly we will use the barbell curl as an example. The reps that you start to reach the point of failure would depend on the weight selected. You should have selected a weight that you can do at least 6 reps with when you reach failure.
Your spotter or training partner then lightens the load by helping you move the weight through a sticking point to complete the curl. Your training partner needs to ensure that he/she is only taking the weight that is stopping the movement, no less and no more help is needed until complete failure is reached.
Forced reps are very similar to drop sets because you are lightening the load and continuing to rep it out, but this time the same weight is used. This is as advanced technique as mentioned above but more important is the spotter or training partner who needs to ensure that only a limited amount of help is given to ensure that you continue with the movement.
The spotter needs to always ensure that the rep speed you are doing the movement with is maintained throughout the movement. Waiting until you stop moving and the movement of the weight reverses direction is too late and not enough assistance is given.
Some bodybuilders used forced reps as a staple in every workout cycle they do because they say it avoids slipping into the dreaded plateau where you cannot increase the weight you lift anymore. It is strongly advised that you use a spotter who has done this before when you first start with forced reps.