Neither heavy nor light lifting made people better at doing more reps in a row—except maybe a small, not certain improvement with lighter lifts in squats.
Scientific Claim
In resistance-trained young men, 8 weeks of volume-equated high-repetition and low-repetition daily undulating periodization programs do not significantly improve muscular endurance in squat or bench press, though a moderate effect size was observed for high-repetition training in squat endurance.
Original Statement
“ME did not significantly change in the squat or bench press for either group (p > 0.05); however, for squat ME, a moderate effect size was observed for DUPHR (0.57) versus a trivial effect size for DUPLR (0.17).”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design cannot support claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The authors correctly report non-significant changes and report effect sizes without overstating significance. The moderate effect size is presented as exploratory, not conclusive.
More Accurate Statement
“In resistance-trained young men, 8 weeks of volume-equated high-repetition and low-repetition daily undulating periodization programs are associated with no significant improvement in muscular endurance for squat or bench press, though a moderate effect size was observed for high-repetition training in squat endurance.”
Evidence from Studies
Supporting (1)
Volume-equated high- and low-repetition daily undulating programming strategies produce similar hypertrophy and strength adaptations.
The study found that doing lots of reps or few reps didn’t make people much stronger at doing many squats or bench presses after 8 weeks, but doing more reps did seem to help a little with squat endurance—even if it wasn’t a huge change.