Exploring the Dose-Response Relationship between Resistance-Training Volume and Psychophysiological Responses in Trained Males
(Alysson Enes, Guilherme Nass, Ragami C. Alves, Adam E. Mohan, Alec Piñero, Gustavo Oneda, Danilo Fonseca Leonel, Brad J. Schoenfeld, Tácito P. Souza-Junior)

We investigated the effects of different weekly-set progressions on perceptual responses and explored whether muscle thickness (MT) responses were related to perceptual and volume metrics in resistance-trained males. Thirty-one participants were randomly assigned to one of the three groups: a fixed set (FS) group (n = 10), maintaining 22 weekly quadriceps sets; a 4-Set (4S) group (n = 10) and a 6-Set (6S) group (n = 11), increasing by four and six every fortnight, respectively. Training occurred twice weekly for 12 weeks. The session rating of perceived exertion (sRPE) and session feelings of pleasure/displeasure (sFPD) were assessed 15 min post-training, while sRPE-derived metrics (monotony and strain) were analyzed weekly. The sRPE was higher in the FS compared to the 4S group (p = 0.046), while sFPD were higher in the FS compared to the 6S group (p < 0.001). Monotony was lower in the 4S than in other groups (p < 0.001). Strain followed a graded dose-response (6S > 4S > FS, p < 0.001). Overall, there were no meaningful correlations between volume load slopes and MT (r < 0.392) or perceptual responses (r < 0.448). These findings suggest that progressive increases in weekly-set volume influence perceptual responses; however, these responses do not appear to be related to changes in muscle thickness.