Its important to remember that it is possible to gain significant amounts of strength without gaining weight. This can be crucial to sports which have weightclasses for athletes such as boxing, wrestling, olympic weightlifting, and mma to name a few. How does it work, and how do you do it? The key is usling maximal weights and use a low volume of reps preferably between 1-3,  and a low-moderate to high volume of sets,  when PURE strength with minimal hypertrophy is the goal. Good ranges for PURE strength include the following, 3x3 6x2 and 8x3. They call this Neuromuscular strength becuase rather than stimulate purely the muscle whiste feeling the burn and the pump like the standard 8-12 rep bodybuilding approach, your stimulating your body's central nervous system by improving in the efficiency of motor unit recruitment patterns as well as the firing syncronization of these patterns allowing you to become more effiecient at a particular movement. Due to the fact that during a set the muscle is under a low time under tention the body does not maximise hypertophy but rather neuromuscular strength, im not saying you wont gain anything, but if size is your goal then this method of training is certainly not optimal.In simple terms this training style will not put on much size but it will make you alot stronger on your big lifts like the bench press, deadlift and squat in particular.