Eight small trials sit under the headline soreness result
Thirty-seven effect sizes came from eight trials with 61 participants between them. Pooled, they produced a large reduction in muscle soreness, an effect size of 0.73.
What the study found
The large soreness effect rests on 61 people in total
Thirty-seven effect sizes sounds like a lot of data. They came from eight small trials with 61 participants between them, and pooling them produced a large reduction in muscle soreness after a hard session, an effect size of 0.73. The effect is large; the base under it is not.
The caveat · Self-rated soreness, not recovery
Soreness is self-reported on a visual scale, and it is a symptom rather than a measure of recovery or performance. The abstract reports no publication-bias check, no risk-of-bias grading and no funding disclosure for the trials pooled, in a field where manufacturers fund much of the primary work.
What we don't know
How much BCAAs ease soreness is unsettled. The largest estimate rests on the thinnest base, never checked for publication bias, while three more careful syntheses of the same question land smaller.