A common training mistake that I see people doing all the time and even promoted through other training programs is the “burnout” set.
This is usually the last set in an exercise that consists of a lighter weight done with high reps to failure. This my friends is very counter-productive to muscle growth from several standpoints and should never be performed.
To get a better understanding as to why you should never do this “burnout” set you must ask yourself why you are doing it in the first place. I’ve heard answers like, “To feel the burn.”, “To stimulate every last muscle fiber.”, “To get the burn and the pump.”, “To finish off the exercise.” to name a few. As you can see all these explanations either make no sense, have no reasoning behind them, or go against the physiological pathways of muscle growth.
Here is an area that little formal research has been done, but enough has been completed to clearly indicate where “muscle memory” plays a prominent role in final overload adaptation, muscle growth, and muscle strength as a result of overload. There is even evidence that this muscle memory is exercise specific.
What this tells me, and is confirmed in the gym, is that your muscles have a “memory-like” effect that dictates the growth resulting from a workout. Strength appears to be even more prominently effected by this “muscle memory.”
Your muscles appear to have a memory effect that is significantly influenced by the last set that you do
If you finish each set with a heavy 4 to 6 rep exercise your muscles remember this and adapt accordingly. This memory effect is an important physiological phenomenon and should be used to your advantage in gaining strength and muscle size. And conversely, this memory effect should be manipulated so it will not impede the muscle growth process.