Background

Prescribing repetitions relative to task failure is an emerging approach to resistance training. Under this approach, participants terminate the set based on their prediction of the remaining repetitions left to task failure. While this approach holds promise, an important step in its development is to determine how accurate participants are in their predictions. That is, what is the difference between the predicted and actual number of repetitions remaining to task failure, which ideally should be as small as possible.

Objective

The aim of this study was to examine the accuracy in predicting repetitions to task failure in resistance exercises.

Design

Scoping review and exploratory meta-analysis.

Search and Inclusion

A systematic literature search was conducted in January 2021 using the PubMed, SPORTDiscus, and Google Scholar databases. Inclusion criteria included studies with healthy participants who predicted the number of repetitions they can complete to task failure in various resistance exercises, before or during an ongoing set, which was performed to task failure. Sixteen publications were eligible for inclusion, of which 13 publications covering 12 studies, with a total of 414 participants, were included in our meta-analysis.

Results

The main multilevel meta-analysis model including all effects sizes (262 across 12 clusters) revealed that participants tended to underpredict the number of repetitions to task failure by 0.95 repetitions (95% confidence interval [CI] 0.17–1.73), but with considerable heterogeneity (Q₍₂₆₁₎ = 3060, p < 0.0001, I² = 97.9%). Meta-regressions showed that prediction accuracy slightly improved when the predictions were made closer to set failure (β = − 0.025, 95% CI − 0.05 to 0.0014) and when the number of repetitions performed to task failure was lower (≤ 12 repetitions: β = 0.06, 95% CI 0.04–0.09; > 12 repetitions: β = 0.47, 95% CI 0.44–0.49). Set number trivially influenced prediction accuracy with slightly increased accuracy in later sets (β = − 0.07 repetitions, 95% CI − 0.14 to − 0.005). In contrast, participants’ training status did not seem to influence prediction accuracy (β = − 0.006 repetitions, 95% CI − 0.02 to 0.007) and neither did the implementation of upper or lower body exercises (upper body – lower body = − 0.58 repetitions; 95% CI − 2.32 to 1.16). Furthermore, there was minimal between-participant variation in predictive accuracy (standard deviation 1.45 repetitions, 95% CI 0.99–2.12).

Conclusions

Participants were imperfect in their ability to predict proximity to task failure independent of their training background. It remains to be determined whether the observed degree of inaccuracy should be considered acceptable. Despite this, prediction accuracies can be improved if they are provided closer to task failure, when using heavier loads, or in later sets. To reduce the heterogeneity between studies, future studies should include a clear and detailed account of how task failure was explained to participants and how it was confirmed.

中文翻译：

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预测阻力练习中任务失败重复的准确性：范围审查和探索性荟萃分析

背景

规定与任务失败相关的重复是一种新兴的阻力训练方法。在这种方法下，参与者根据他们对任务失败的剩余重复次数的预测来终止集合。虽然这种方法很有希望，但其发展的一个重要步骤是确定参与者的预测有多准确。也就是说，任务失败后剩余的预测重复次数和实际重复次数之间的差异是多少，理想情况下应该尽可能小。

客观的

本研究的目的是检查在阻力练习中预测重复任务失败的准确性。

设计

范围审查和探索性荟萃分析。

搜索和包含

2021 年 1 月，使用 PubMed、SPORTDiscus 和 Google Scholar 数据库进行了系统的文献检索。纳入标准包括对健康参与者的研究，这些参与者预测了他们可以在各种阻力练习中完成任务失败的重复次数，在针对任务失败进行的持续组之前或期间。16 篇出版物符合纳入条件，其中 13 篇出版物涵盖 12 项研究，共有 414 名参与者，被纳入我们的荟萃分析。

结果

主要的多级荟萃分析模型包括所有效应量（12 个集群中的 262 个）显示，参与者倾向于低估重复任务失败的重复次数 0.95 次（95% 置信区间 [CI] 0.17-1.73），但具有相当大的异质性（Q ₍₂₆₁₎  = 3060，p  < 0.0001，I ²  = 97.9%）。元回归表明，当预测更接近设定失败时（β  = - 0.025, 95% CI - 0.05 到 0.0014）以及针对任务失败执行的重复次数较低（≤ 12 次重复：β  = 0.06, 95% CI 0.04–0.09；> 12 次重复：β = 0.47, 95% CI 0.44–0.49)。组数对预测准确性的影响微乎其微，后期组的准确性略有提高（β  = - 0.07 次重复，95% CI - 0.14 至 - 0.005）。相比之下，参与者的训练状态似乎不影响预测准确性（β  = - 0.006 次重复，95% CI - 0.02 至 0.007），上肢或下肢锻炼的实施（上肢 - 下肢 = - 0.58 次重复）也没有影响; 95% CI - 2.32 至 1.16)。此外，参与者之间的预测准确性差异很小（标准偏差 1.45 次重复，95% CI 0.99–2.12）。

结论

参与者在独立于他们的培训背景的情况下预测接近任务失败的能力是不完美的。观察到的不准确程度是否应该被认为是可以接受的还有待确定。尽管如此，如果在更接近任务失败、使用较重负载时或在以后的集合中提供预测精度，则可以提高预测精度。为了减少研究之间的异质性，未来的研究应该包括清楚详细地说明如何向参与者解释任务失败以及如何确认。