The Claim

In previously untrained healthy young men, after 15 weeks of resistance training, changes in quadriceps muscle volume are a more than fivefold stronger predictor of knee extension strength gains than changes in normalized neuromuscular activation, with standardized beta coefficients of 0.88–0.94 versus 0.13–0.17 in linear mixed models.

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.

Quantitative
1 study reviewed
In plain English

After 15 weeks of resistance training in previously untrained healthy young men, increases in quadriceps muscle size predict increases in knee extension strength more than five times better than changes in nerve-to-muscle signal efficiency, based on statistical coefficients from linear models.

See the scientific wording

In previously untrained healthy young men, changes in quadriceps muscle volume are a more than fivefold stronger predictor of knee extension strength gains than changes in normalized neuromuscular activation after 15 weeks of resistance training, as indicated by standardized beta coefficients of 0.88–0.94 versus 0.13–0.17 in linear mixed models.

Why this might work

When muscles are repeatedly stressed during strength training, they grow larger by adding more contractile proteins. This increase in muscle size means more protein filaments can pull together at the same time, producing more force. The bigger the muscle gets, the stronger it becomes — much more than any improvement in how the nerves signal the muscle to contract.

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

    After 15 weeks of leg workouts, people got stronger mainly because their thigh muscles grew bigger—not because their nerves got better at firing. Muscle growth explained over five times more of the strength gain than changes in muscle electrical activity.

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

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