Resistance training systems: Forced reps

To employ forced reps, the client performs as many reps on his/her own as they can until the point of failure is reached. At this point, the trainer provides a minimal amount of assistance to permit the performance of another rep. As the client fatigues further, the trainer will provide slightly more assistance each rep for a total of 2-4 reps before terminating the set. This process is merely an extension of normal spotting procedures. It is important to note that at no point should the trainer be helping to the degree that they are doing more work than the client! If this is the case, the load is too great or the set has been extended too far beyond failure.

Active IQ, Level 3 certificate in personal training, programming personal training with clients (2014)