Women who had never lifted weights before got stronger in their arms and legs after doing 12 weeks of lifting light or heavy weights to exhaustion — and both ways made them just as strong.
Scientific Claim
Resistance training to failure at 30% one-repetition maximum (1RM) and 80% 1RM for 12 weeks results in similar increases in 1RM strength across four exercises (leg extension, seated military press, leg curl, and lat pull-down) in untrained women, with average strength gains ranging from 23% to 32% over the intervention period.
Original Statement
“The 1RM strength increased from week 1 to week 12 (LE: 32 ± 24%; SMP: 17 ± 14%; LC: 23 ± 26%; LPD: 25 ± 13%)... with no significant differences between groups.”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design cannot support claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The abstract does not confirm randomization or control for confounders, so causation cannot be assumed. The claim implies equivalence as a universal truth, but the study only shows an observed association in a small, unrandomized group.
More Accurate Statement
“In untrained women, resistance training to failure at either 30% or 80% 1RM for 12 weeks is associated with similar increases in 1RM strength across four exercises, with average gains of 23–32%, though causation cannot be confirmed without verified randomization.”
Evidence from Studies
Supporting (1)
Low-Load vs. High-Load Resistance Training to Failure on One Repetition Maximum Strength and Body Composition in Untrained Women.
This study found that lifting light weights or heavy weights to exhaustion for 12 weeks helped untrained women get just as much stronger, no matter which weight they used.