Inter-Individual Variability in Repetitions to Failure Across Relative Loads During the Prone Bench Pull in Highly...

Background : This study examined the maximum number of repetitions (MNR) that can be completed to muscular failure at different relative loads in the prone bench pull (PBP) exercise, its inter-individual variability, and potential anthropometric factors associated with this variability in male and female highly trained rowers. Methods: Twenty-five national- and international-level rowers (16 men and 9 women) completed an incremental loading test to determine the one-repetition maximum (1RM) and velocity associated with each relative load, followed by four sets to muscular failure at 50, 60, 70, and 80% 1RM, performed in a randomized order, with 5-7 days between sessions. Peak velocity of the fastest (Vmax-Best) and last (Vmax-Last) repetitions, velocity loss (VL), and MNR were recorded. Results: MNR progressively decreased as relative load increased (p < 0.001), ranging from 38.2 ± 7.1 to 9.4 ± 2.2 repetitions in men and from 46.9 ± 9.7 to 10.4 ± 2.3 repetitions in women. Considerable inter-individual variability in MNR was observed across relative loads (CV = 14.2-25.8%) for both sexes. Vmax-Best progressively decreased with increasing relative load (p < 0.001), whereas no statistically significant differences in Vmax-Last were detected across loads (p = 0.606), with lower values observed in women than in men (p < 0.001). A significant relative load × sex interaction was observed for MNR (p = 0.043), with women completing more repetitions than men at 50% 1RM. Neither Vmax-Best nor the anthropometric variables showed consistent associations with MNR across relative loads. Conclusions: These findings indicate substantial inter-individual variability in the MNR at a given relative load and question the use of fixed repetition targets to prescribe resistance-training volume. Monitoring repetition velocity and VL may be useful for individualizing set volume in trained rowers.