Original article written by Simon Lovegrove, Liam Hughes, Sean Mansfield, Paul Read, Phil Price, Stephen Patterson
Background
Prescribing and monitoring resistance training loads continues to be a hot topic in performance sport. Despite velocity-based training stealing the headlines in recent years, autoregulation continues to be a method of choice for many resistance training practitioners. The concept of autoregulation was first documented in the 1940’s and involves the manipulation of lifting load based on an individual’s perceived capability to perform[1]. Contemporary interest in this space has specifically focused on prescribing repetitions relative to task failure, otherwise known as repetitions in reserve (RIR). But can you reliably estimate your RIR during resistance exercise?
A recent paper published by Simon Lovegrove and colleagues in The Journal of Strength & Conditioning Research sought to examine the reproducibility of load lifted at 1 RIR in novice, male, lifters during the deadlift and bench press exercises. Whys this important? Well, if you’re prescribing RIR for a fixed set of repetitions (say, 4 reps at 1 RIR) and the load lifted by an individual changes between sessions, you’ll likely want some assurance that it’s because of genuine fluctuations in their fitness–fatigue state, rather than their inability to reliability gauge RIR.
What the authors did
In the study, 15 participants (age: 17.6 ± 0.9 years, stature: 176.0 ± 8.8 cm, body mass: 71 6 11 kg) visit the lab on 4 occasions, each separated by one week. The first visit was used to establish deadlift and bench press one repetition maximum (1RM; 118 ± 27 kg and 58 ± 19 kg, respectively) and the second visit was used to familiarise with the trial protocols subsequently performed in visit 3 and 4.
On both trial occasions, participants performed multiple sets of each exercise using 3 different repetition schemes (3, 5, and 8 repetitions). Initial set loads were 75%, 70% and 65% of 1RM, respectively. Heavier loads were then used for each subsequent set until the participants felt they had reached 1 RIR, which was instructed from a previously developed RIR scale[2]. The load at 1 RIR was then retained for between-visit reliability analysis. A rep scheme was performed for multiple sets, with 3 minutes rest between sets, until the 1 RIR load was complete, before moving to the next repetition scheme after a 5-minute rest. Importantly, rep schemes were randomised in their completion to reduce any potential order effects.
What the authors found
The mean relative loads lifted to 1 RIR for 3, 5 and 8 repetitions in the deadlift and bench press were 88%, 84% and 77% 1RM, and 93%, 87% and 80% 1RM, respectively. The intraclass correlation coefficient (ICC)—a measure of relative reliability and reproducibility in the rank order of retesting—of the final 1 RIR load lifted was ≥ 0.95 all rep schemes in both exercises, which is regards as very high reliability[3]. Interestingly, ICC values were marginally higher for 3 and 5 repetitions when compared to 8 repetitions. The coefficient of variation (CV)—a relative measure of random, within-subject variability—was ~3–4% for 3 and 5 repetitions, respectively, and ~6% for 8 repetitions in both exercises. Here, you can see a similar pattern to previous in that reliability appears improved (a lower CV) at lower rep ranges. The bottom-line from these findings is that RIR provide a highly reliable method for prescribing resistance training loads; at least, in young, male, novice lifters performing the deadlift and bench press exercises for ≤ 8 repetitions at an intensity corresponding to 1 RIR.
Limitations
The authors rightly acknowledge that the strength levels of novice lifters can change over the course of a four-week period, meaning that the objective prescription of loads lifted (from %1RM) may have varied throughout the study. I personally doubt this had much effect on the overall results and conclusions though. Lovegrove & co. also acknowledge that their results are specific to the context of the study and might not necessarily transfer to other populations (beyond novice male lifters), exercises (other than the deadlift and bench press) or training loads (different rep schemes and RIR more than 1).
What this means for coaches?
Practitioners prescribing similar rep schemes and training loads to young male novice lifters for exercises such as the deadlift and bench press can use RIR with confidence, knowing that any between-week changes in the load lifted at 1 RIR are likely due to ‘true’ physiological or psychological factors, as opposed to error in the RIR process. It also seems that the reliability of RIR is better at lower repetition schemes (3–5) when compared to higher repetition schemes (8), which makes sense given that prediction accuracy (perceived vs actual RIR) improves when the number of repetitions performed to task failure are lower[4]. I also think this suggests RIR can be used to monitor resistance training loads, as well as prescribe them. Having athletes note their RIR along with load lifted and repetitions complete might facilitate the quantification of relative volume load, for example[5].
Reviewer’s comments
The concept of RIR is strong in its theoretical rational, pragmatism and potential impact. This study was well designed and conducted by Lovegrove et al., offering great practical insight. It would have been nice to see the CVs expressed in kilograms (i.e., the standard error of measurement) to give a more interpretable value of measurement error in ‘weight room terms’. Using their reported data, I’ve crudely estimated these as 3–5 kg for the deadlift and 2–3 kg for the bench press, which further supports the claim of high reliability (in my opinion). Understanding if/how this reliability extends to RIR greater than 1 is an important next step for research in this area.
Recommended resources
- Article – Autoregulation in resistance training: addressing the inconsistencies – Leon Greig
- Article – Training monitoring for resistance exercise: Theory and applications – Brandan Scott
- Podcast – APRE and autoregulation training – Bryan Mann