In resistance training, the use of predicting proximity to momentary task failure (MF, i.e., maximum effort), and repetitions in reserve scales specifically, is a growing approach to monitoring and controlling effort. However, its validity is reliant upon accuracy in the ability to predict MF which may be affected by congruence of the perception of effort compared with the actual effort required. The present study examined participants with at least 1 year of resistance training experience predicting their proximity to MF in two different experiments using a deception design. Within each experiment participants performed four trials of knee extensions with single sets (i.e., bouts of repetitions) to their self-determined repetition maximum (sdRM; when they predicted they could not complete the next repetition if attempted and thus would reach MF if they did) and MF (i.e., where despite attempting to do so they could not complete the current repetition). For the first experiment (n = 14) participants used loads equal to 70% of a one repetition maximum (1RM; i.e., the heaviest load that could be lifted for a single repetition) performed in a separate baseline session. Aiming to minimize participants between day variability in repetition performances, in the second separate experiment (n = 24) they used loads equal to 70% of their daily isometric maximum voluntary contraction (MVC). Results suggested that participants typically under predicted the number of repetitions they could perform to MF with a meta-analytic estimate across experiments of 2.0 [95%CIs 0.0 to 4.0]. Participants with at least 1 year of resistance training experience are likely not adequately accurate at gauging effort in submaximal conditions. This suggests that perceptions of effort during resistance training task performance may not be congruent with the actual effort required. This has implications for controlling, programming, and manipulating the actual effort in resistance training and potentially on the magnitude of desired adaptations such as improvements in muscular hypertrophy and strength.

In resistance training, the ability to predict momentary task failure (MF; i.e. maximum effort) during submaximal exercise may be affected by congruence of how (sub-)maximal effort is perceived compared with the actual effort required. The present study examined participants with at least one year of resistance training experience predicting their proximity to MF in two different experiments using a deception design. Participants performed four trials of knee extensions with single sets to their self-determined repetition maximum (sdRM) and MF using a baseline 70%1RM in the first experiment (n = 14). Aiming to minimize participants’ variability in repetition performances, they performed at 70% of their daily MVC instead of their baseline 1RM in the second experiment (n = 24). Results suggested that participants typically under predicted the number of repetitions they could perform to MF. These results suggest that participants with at least one year of resistance training experience are not adequately accurate at gauging effort in submaximal conditions during the gestalt experience of resistance training. This suggests that perceptions of effort during RT task performance may not be congruent with the actual effort required. This has implications for controlling, programming and manipulating effort in RT and potentially on the magnitude of desired adaptations such as improvements in muscular hypertrophy and strength.