Better effort regulation with estimated repetitions to failure during resistance training

During resistance training, having a predetermined number of repetitions may be more enjoyable than the emerging estimated repetitions to failure (ERF) approach, a recent study has found. However, ERF may allow for better effort regulation between exercise sets.

The study included 20 women (aged 23–45 years) with no prior resistance training experience. Over three sessions, participants were made to perform four exercises: leg press, chest press, knee extension, and lat-pulldowns. During the predetermined-repetition condition, participants were asked to perform 10 repetitions of each exercise during each set; under the ERF condition, they performed as many as required until they felt two repetitions away from failure.

The primary study outcomes were affective-valence, enjoyment, and preference. The number of repetitions completed per exercise was set as the secondary outcome.

Affect-valence was measured using the Feeling Scale (FS), which revealed a slight but significant advantage of having a predetermined number of scales (mean, 3.29±0.89 vs 3.01±9.95; p=0.006). The difference in FS scores from before to after exercise was comparable between arms (p=0.13).

Participants likewise enjoyed having a predetermined number of repetitions more as opposed to ERF, though the difference failed to reach significance. In terms of personal preference, eight participants said they preferred ERF, while the rest chose the predetermined approach.

“While the mean number of repetitions across all exercises was similar, under the ERF condition participants demonstrated greater variability in repetition numbers between participants and exercises. Since they maintained a similar proximity to task failure, the invested effort across exercises was likely better standardized compared to the predetermined approach,” the researchers said.

“Given these results, resistance training coaches can attempt to optimize the training experience by introducing both approaches and selecting one or the other based on their trainees’ preferences,” they added.