Prescrição baseada em zonas de intensidade (% 1RM): valências fisiológicas, cinética de fadiga e respostas neuromusculares no treinamento de força

The manipulation of operational variables in resistance training (RT)—specifically intensity (expressed as a percentage of one-repetition maximum, % 1RM), repetition volume, number of sets, contraction cadence, and recovery intervals—is the primary determinant of the specificity and magnitude of biological adaptations. This article aims to systematize and provide a neurophysiological foundation for the spectrum of intensities ranging from 40% to 100% of 1RM, correlating each effort zone with its predominant metabolic, structural, or neural characteristics. The mechanisms governing Henneman’s Size Principle, mechanosensitive anabolic pathways (mTORC1 and MAPK), the accumulation of cellular byproducts resulting from muscular acidosis, and the kinetics of phosphocreatine resynthesis are analyzed. A detailed synoptic matrix and guidelines for applying these principles within a block periodization framework for trained individuals and high-performance athletes are also presented.