High-intensity training is at the core for developing the huge, ripped-to- the-bone musculature displayed by today's top international
bodybuilding champions. Virtually every current champ pushes his sets at least to the point of failure, and most of them forge beyond by
using cheating reps, descending sets and/or forced repetitions.
To my way of thinking, forced reps constitute the best method serious bodybuilders have of pushing a set past muscular failure, because both cheating reps and descending sets have serious drawbacks.
With cheating, you'll find that you either impart too little momentum to the bar, which then stalls part way up on a rep, or too much force, in which case the bar literally flies up to the finish point and fails to stress the working muscles.
With descending sets, normally the limiting factor is the need for two training partners it most movements are to be performed properly. Failure to complete a repetition at the end of a set means that the muscles have become too fatigued to push out that particular amount of weight. If you couldn't finish a rep with 225 on an incline barbell press, for example, chances are you still could push out 210 or 215 pounds for an additional rep, and perhaps 200 or 205 for yet another rep. The key would be to remove precisely that 10 or 15 pounds from the original poundage for the first additional repetition and the 20 or 25 pounds for a second rep.
Obviously, you can't be precise when you cheat up a rep. It's also difficult in many exercises such as the incline presses just suggested to cheat up the weight at all. But if you have a training partner assist with precisely enough pressure to allow you to force out each rep past failure, you'll be able to push the muscles farther than ever before, and that will absolutely result in greater muscle hypertrophy - larger mass and sharper muscularity at contest time.
You probably shouldn't do more than a couple of forced reps - certainly no more than three - at the end of a set. Pushing a muscle past failure causes such a profound state of momentary fatigue that your muscles will fail to contract with any meaningful amount of force past the second or third extra repetition. And when they can't contract forcefully, they won't receive much muscle-building benefit.
It's quite possible to over train from doing too many forced reps, so you should introduce them very slowly into your program, watching carefully for any signs of overtraining. Add only one forced-rep set per muscle group for the first six to eight weeks, then gradually add one more per muscle group every two or three months. When you're doing forced reps at the end of every post-warm-up set in a body part routine, you'll be frying your muscles and forcing them to grow as rapidly as humanly possible.