In conventional weightlifting you usually are performing sets and reps. In a normal set of weightlifting you begin the movement at literally zero resistance, then as you perform the rep you move into a range of medium resistance, and lastly moving ion the position of MAXIMUM resistance. It is this very final position of maximum muscle contraction that yields the most benefit in terms of trying to stimulate the muscle fibers that is the goal of any strength-training program. Ironically this position is seldom if ever utilized in boring old conventional training methods.
If you have ever been to the gym to work out you know the hardest rep of a set is the very last rep. WHY NOT then go to the very last rep FIRST! Not only are sets and reps a huge waste of time, they deplete very valuable energy and chemicals at a cellular level thus negating any chance of allowing you to ever achieve a fully optimal work out. The only way to stimulate your body for optimal growth regarding strength and size is forcing the body to recruit as many muscle fibers as possible during a given exercise. This is achieved only by working out in the strongest range or position (near lock out), with the highest amount of resistance possible.
Intensity and duration are inversely proportional. In other words NO ONE can push or pull at maximum force (intensity) for more than just a few seconds. In fact every professional, collegiate, and Olympic athlete I’ve ever trained as well as all the other non athlete trainees hit their peak value within 7-10 seconds as long as their intensity is maximum. Sure one can still be generating some amount of force for longer than 7 or 8 seconds but the “PEAK” will never be achieved again in that 1 maximum REP. Therefore is necessary to perform only 1 REP per exercise for optimal results. Any more than that and you completely screw up your recovery. Even if you perform one more single rep with max weight or effort as Arthur Jones studied and proved decades ago.