Older women who started out weaker in their legs got stronger in their legs more than the stronger ones after doing leg exercises for 12 weeks, but everyone gained about the same amount of muscle and upper-body strength.

Scientific Claim

Among older women, resistance training for 12 weeks is associated with greater increases in leg extension strength for those with lower baseline strength compared to those with higher baseline strength, despite similar gains in upper-body strength and muscle mass.

Original Statement

“Changes were greater in WKR than STR for 1RM leg extension [ESdiff = −0.45 (95%CI: −0.86, −0.04), P = 0.030].”

From study:Weaker older women gain more lower body strength than their stronger counterparts, but not muscle mass, following 12 weeks of resistance training

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 specify randomization or control group status, so causation cannot be confirmed. The language implies a differential effect, but only an association can be claimed. The effect size and p-value support the association, not causation.

Evidence from Studies

Supporting (1)

Weaker older women gain more lower body strength than their stronger counterparts, but not muscle mass, following 12 weeks of resistance training

Cohort Study

Human

2022 Dec

Older women who started out weaker in their legs got stronger in their legs much more than those who were already strong, even though everyone gained the same amount of muscle and upper-body strength.

Contradicting (0)

No contradicting evidence found

Source Study

Weaker older women gain more lower body strength than their stronger counterparts, but not muscle mass, following 12 weeks of resistance training

Score: 49

DOI: 10.1080/02640414.2023.2189789

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