REF-1509 · Hammert et al., 2025 · Journal of Strength and Conditioning Research · Paper · PubMed

Will lifting add reps at a fixed station load?

Review of 51 studies: reps at a fixed load rise far more reliably than reps at a % of current max. Fixed-load reps resemble a station (inference); no station was tested.

Main caveat: Abstract only. The journal is closed and no open copy was found by identifier.
moderate evidenceMeasured on non-athletes to highly trained athletes

Hammert and colleagues set out how to assess changes in local muscular endurance, separating absolute tests (as many repetitions as possible against the same external load before and after training) from relative tests (a load scaled to the person's current maximal strength).

A systematic search gave 7,473 articles, of which 51 studies met the inclusion criteria: 40 indicated an absolute (17) or a relative test (20), 3 of those used both, and 11 did not clearly say. The authors conclude that the literature suggests absolute muscular endurance is much more likely to increase after resistance training than relative muscular endurance.

Protocols with the most robust effects on relative endurance used lower loads and/or more repetitions per set, which "might be a consequence" of producing smaller strength gains. They also found a notable lack of clarity about how endurance was studied, and ask future work to report the test type and to control or report repetition cadence.

Our reading: the useful point is about measurement. "Muscular endurance got better" means different things under the two tests, and a trial that does not say which it used cannot be read for a fixed race load. The abstract does not say that heavy training is the best way to raise absolute endurance; it gives no comparison of loads on that test.

Protocol

Design: review of the literature with a systematic search; n = 51 studies from 7,473 articles.
Test split: 40 studies stated a test: absolute n = 17, relative n = 20, both 3; 11 did not clearly indicate which.
Definitions (authors): absolute = as many repetitions as possible at pre- and post-intervention against the same external load; relative = a load that scales to the individual's current level of maximal strength.
Not in the abstract: search dates, databases, populations, risk-of-bias method, any effect size.
Funding and interests: not given in the abstract; full text not read.

Key Results

ItemAs reported (abstract)
Records7,473 articles; 51 studies included
Test usedabsolute 17, relative 20, of which 3 used both; 11 unclear
Main conclusionabsolute muscular endurance "much more likely" to increase after resistance training than relative
Relative endurancemost robust effects with lower loads and/or more repetitions per set
Effect sizesnone given in the abstract

Mechanisms

Measured: the count of studies by test type, and the direction of change across the literature as the authors summarise it.
Authors' interpretation: the stronger response of relative endurance to lower loads or higher repetitions might be a consequence of those protocols producing smaller strength increases.
Inference: a relative test's load rises with strength, so whoever gains less strength is retested at a smaller rise. A person who gets stronger meets a fixed load at a lower share of their maximum, which would explain why absolute tests rise so readily. The abstract does not state this mechanism and tests nothing at a race load.

Practical Application

Will lifting add reps at a fixed station load? Review of 51 studies: reps at a fixed load rise far more reliably than reps at a % of current max. Fixed-load reps resemble a station (inference); no station was tested.
Read endurance claims by their test. The abstract's support for "high reps build muscular endurance" is on relative tests, where lower loads or more reps gave the most robust effects, and the authors suggest that may partly reflect a smaller strength rise. For a fixed race load the absolute result is the closer analogue (inference).
What it does not show: that heavy training beats high-rep training for a race load, or the reverse; the abstract compares no loads on the absolute test. REF-1510 did compare them on one fixed-load test and found no significant difference, with a wide interval.
Not from this paper; the base's own practice: heavy strength short of failure stays the default for force and for running (SYNTH-44, SYNTH-71); SYNTH-71 lists high-repetition vs heavy work for station time as a gap, and its station sessions are practice.

Limitations

Abstract only. The journal is closed and no open copy was found by identifier; populations, study quality and any effect size were not read, and nothing here should be quoted beyond the abstract.
No pooled estimate in the abstract. "Much more likely" is a summary, not a number.
Reporting in the source literature. 11 of 51 studies did not make the test clear, and the authors urge future work to control or report cadence; how many studies failed to is not in the abstract.
No race or station outcome. Tests are resistance exercises to failure; nothing under lactate, after running or in hybrid athletes is named.
Funding and conflicts: not available from the abstract.
How this entry was checked and changed
Why this level

a systematic search across a large literature, but no pooled effect is reported in the abstract, the conclusion is worded as what the literature "suggests", and the authors themselves flag unclear reporting; the review's own methods and risk-of-bias handling were not read