Impact of Lifting Straps on the Relationship Between Maximum Repetitions to Failure and Lifting Velocity During the Prone Bench Pull Exercise.

Abstract

Background: Fastest mean (MV_fastest) and peak (PV_fastest) velocity of the set have been proposed to predict the maximum number of repetitions to failure (RTF) during the Smith machine prone bench pull (PBP) exercise.

Hypothesis: Goodness-of-fit would be higher for individualized compared with generalized RTF-velocity relationships and comparable for both execution equipment conditions (with or without straps), and the MV_fastest and PV_fastest associated with each RTF would be comparable between execution equipment and prediction methods (multiple- vs 2-point method).

Study design: Cross-sectional study.

Level of evidence: Level 3.

Methods: After determining the PBP 1-repetition maximum (1RM), 20 resistance-trained male athletes performed 2 sessions randomly, with and without lifting straps, consisting of single sets to failure against the same load sequence (60% to 80% to 70% 1RM). Generalized (pooling data from all subjects) and individualized (separately for each subject using multiple-point or 2-point methods) RTF-velocity relationships were constructed.

Results: Individualized RTF-velocity relationships were always stronger than generalized RFT-velocity relationships, but comparable with (MV_fastest: r² = 0.87-0.99]; PV_fastest: r² = 0.88-1.00]) and without (MV_fastest: r² = 0.82-1.00; PV_fastest: r² = 0.89-0.99]) lifting straps. The velocity values associated with each RTF were comparable between execution equipment (P ≥ 0.22), but higher for the multiple-point compared with the 2-point method (P < 0.01).

Conclusion: The use of lifting straps during the Smith machine PBP exercise does not affect the goodness-of-fit of the RTF-velocity relationships or the velocity values associated with different RTFs. However, caution should be exercised when using different methods.

Clinical relevance: The benefits of the RTF-velocity relationships can be extrapolated when using lifting straps, and the 2-point method can also be used as a quick and more fatigue-free procedure. Nevertheless, it is imperative for coaches to ensure that these relationships are reflective of fatigue experienced during training.