Weekly volume, not its division into sessions, predicts hypertrophy: a re-analysis of a published dose-response dataset

Weekly resistance-training volume has a positive, decelerating dose-response with hypertrophy, and a preprint describes a similar curve for volume per session.Because weekly volume equals per-session volume multiplied by frequency, the per-session coefficient at fixed weekly volume is the coefficient for dividing that volume into more sessions with its sign reversed, so the persession curve carries information beyond weekly volume only if this partitioning effect is nonzero.We re-analyzed the dataset deposited with Pelland et al. (2026), restricted to direct, sitespecific hypertrophy measures (220 effects from 35 randomized trials; 963 participants).Multilevel meta-regressions with cluster-robust inference fitted the identity's decompositions, estimated the partitioning effect within studies from assigned frequency contrasts, and pooled the 15 trials comparing frequencies at equal weekly volume.Weekly volume at fixed frequency was associated with hypertrophy (b = 0.170 SMCR per unit ln sets, 95% CI 0.076 to 0.263).The partitioning coefficient was close to zero in every estimator (-0.043, 95% CI -0.161 to 0.074; within studies -0.063, -0.194 to 0.069; equal-volume trials 0.016, -0.186 to 0.217, per unit ln frequency).Its 90% interval excluded effects larger than about 0.10 SMCR for a doubling of sessions in the main analysis and about 0.12 to 0.13 SMCR in the contrast-based analyses, bounds close to the effect of doubling weekly volume (0.12).The coefficient stayed between -0.051 and -0.020 across five specifications addressing exercise-induced swelling and within its original interval under study-quality and ultrasound-modality restrictions and alternative set counting.Prescription descriptors did not detectably modify the volume slope (imprecise tests).For strength, the same model gave a positive partitioning coefficient (0.162, 0.031 to 0.293), although not from assigned contrasts alone.In mostly male samples training 1 to 4 sessions per muscle per week, weekly volume was associated with hypertrophy and its division into sessions made no detectable difference.