The Claim

Within-participant repeated-measures correlation shows a substantially stronger association between muscle growth and strength gains (r = 0.89–0.92) than between-participant correlation (r = 0.35–0.60) in previously untrained healthy young men undergoing 15 weeks of resistance training.

Source: Muscle Growth Is Very Strongly Correlated with Strength Gains after Lower Body Resistance Training: New Insight from Within-Participant Associations

What the research says

Supports is higher

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

Supports
67score
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.

Correlation
1 study reviewed
In plain English

In healthy young men new to resistance training, changes in muscle size within each individual over 15 weeks are strongly linked to changes in strength, while differences in muscle size and strength between individuals are only weakly linked.

See the scientific wording

Within-participant repeated-measures correlation reveals a substantially stronger association between muscle growth and strength gains than between-participant correlation in previously untrained healthy young men undergoing 15 weeks of resistance training, with within-participant r = 0.89–0.92 versus between-participant r = 0.35–0.60.

Why this might work

When muscles are repeatedly stressed by lifting weights, they grow larger by adding more contractile proteins. This increase in muscle size allows more force to be generated with each contraction, directly making the person stronger. The bigger the muscle gets, the stronger it becomes, and this relationship is very tight for each individual over time.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: Muscle Growth Is Very Strongly Correlated with Strength Gains after Lower Body Resistance Training: New Insight from Within-Participant Associations

    When scientists track how one person changes over time, they found that as their muscles got bigger, their strength almost always went up too — and this link was super strong. But when they just compared different people to each other, the link looked much weaker, which shows how you analyze the data really changes what you see.

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

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