REF-677 · Schoenfeld, Grgic, Ogborn & Krieger, 2017 · Journal of Strength and Conditioning Research, · Paper · PubMed
Hypertrophy is similar across light (≤60% 1RM) and heavy (>60% 1RM) loads taken to failure
But maximal (1RM) strength favours heavy loads
Protocol
Inclusion: experimental trials with both low-load (≤60% 1RM) and high-load (>60% 1RM) training, all sets performed to momentary muscular failure, at least one measure of muscle mass or dynamic/isometric/isokinetic strength, ≥6 weeks, healthy participants. 21 studies included.
Key Findings
Changes in muscle hypertrophy were similar between low- and high-load conditions.
1RM strength gains were significantly greater with high loads; isometric strength did not differ between conditions.
The authors' conclusion: maximal strength benefits come from heavy loads, while hypertrophy can be achieved equally across a spectrum of loading ranges.
Practical Application
Across 21 trials (≥6 weeks, sets to failure), muscle growth did not differ between loads ≤60% 1RM and >60% 1RM, but 1RM strength rose more with the heavier loads. Grow muscle with whatever load you can push to failure — light or heavy; when 1RM strength is the goal, train heavy.
Use rep-range flexibility to manage joints, fatigue and preference without sacrificing hypertrophy. Not from this paper; the base's own practice: keep the heaviest strength work at roughly ≤6 repetitions per set.
Limitations
"To failure" is the inclusion condition — the meta-analysis says nothing about light loads stopped far from failure.
The abstract does not report effect sizes, participant numbers or the training status of the pooled cohorts.
How this entry was checked and changed
Content correction 2026-09-27
"low (>15 RM) and high (<15 RM) loads" -> the abstract defines low load as ≤60% 1RM and high load as >60% 1RM; RM thresholds replaced.
"near failure" -> the inclusion criterion was sets performed to momentary muscular failure. Added the isometric-strength null result and the 21-study count.
"~≤6 RM" for strength relabelled as the base's own practice (not in the abstract).
Revision 2026-10-16: cross-reference to SYNTH-89 (static-dynamic, slow no-relaxation light-load training) added. Content and level unchanged. (SYNTH-89)