The Claim

Resistance training targeting specific muscle groups induces hypertrophy in the recruited muscles (increasing volume by 2.2% to 17.7%) and concurrent atrophy in nonrecruited muscles, such as the adductor magnus and soleus (decreasing volume by 1.5% to 2.4%), over a 10-week intervention period.

Source: Evidence for Simultaneous Muscle Atrophy and Hypertrophy in Response to Resistance Training in Humans

What the research says

Supports is higher

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

Supports
39score
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.

Cause and effect
1 study reviewed
In plain English

If you do targeted strength training for a few weeks, the muscles you work will grow bigger, but the muscles you don't use during those exercises might actually shrink a little bit. This happens because your body adapts specifically to the exact movements you're doing.

See the scientific wording

Resistance training targeting specific muscle groups leads to hypertrophy in recruited muscles (+2.2% to +17.7% volume increase) while simultaneously causing atrophy in nonrecruited muscles like the adductor magnus (−1.5%) and soleus (−2.4%) over a 10-week period.

What the research says

1 study
  1. Study: Evidence for Simultaneous Muscle Atrophy and Hypertrophy in Response to Resistance Training in Humans

    The study confirms that when you train specific muscles for 10 weeks, those muscles grow, but untrained muscles in the same body actually shrink slightly.

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

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