The distinction between direct and indirect resistance training sets significantly influences the accuracy of dose-response predictions for muscle hypertrophy and strength, with the 'fractional' quantification method providing the strongest evidence.

When you lift weights in exercises that isolate one muscle, that muscle feels more pull and stress than when you do compound moves that spread the effort across many muscles. This difference in how hard each muscle is working changes how much it grows or gets stronger, and counting each exercise equally gives wrong predictions. Giving more weight to exercises that target one muscle accurately reflects how much actual stress each muscle receives.