The Claim

Circulating levels of insulin-like growth factor 1 (IGF-1) and dehydroepiandrosterone sulfate (DHEA-S), as well as muscle mRNA expression of IGF-1, IGFR1, and myogenin, do not account for the observed gender difference in resistance-training-induced myofiber hypertrophy among older adults.

Source: Gender differences in resistance-training-induced myofiber hypertrophy among older adults.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
37score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

In older adults who do resistance training, the difference in muscle growth between men and women is not caused by differences in the blood levels of IGF-1 or DHEA-S, or by the activity levels of IGF-1, IGFR1, or myogenin genes in muscle tissue.

See the scientific wording

The observed gender difference in resistance-training-induced myofiber hypertrophy among older adults is not explained by circulating levels of insulin-like growth factor 1 (IGF-1) or dehydroepiandrosterone sulfate (DHEA-S), nor by muscle mRNA expression of IGF-1, IGFR1, or myogenin.

Why this might work

When older men and women lift weights, their muscles respond differently because their muscle fibers are activated in distinct patterns and their muscle repair cells respond differently, even though the same growth signals are present in both genders.

Suggested mechanismbased on 1 study

What the research says

1 study
  1. Study: Gender differences in resistance-training-induced myofiber hypertrophy among older adults.

    Scientists found that when older men and women gain muscle from weight training, the difference between them isn’t because of the usual growth hormones or muscle genes they measured — so something else must be causing it.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

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