Research

Energy balance

BCAA supplementation does not improve exercise performance, contradicting the hypothesis that BCAAs serve as a significant fuel source during exercise.

Do not buy BCAA supplements expecting them to boost your workout performance. The evidence shows they do not enhance performance when used as fuel.

GoodRefutesHIGH confidence
it now seems certain from the weight of accumulated evidence that ingestion of BCAAs does not lead to any marked effect on performance—either enhancement or diminution... there is no good published evidence of a beneficial effect of BCAAs on exercise performance as a result of their use as a fuel, and we must conclude that there is none.
Michael J. Rennie et al. · Annual Review of Nutrition · 2000

Why this rating

Based on accumulated evidence reviewed in the paper.

Source

P<scp>ROTEIN AND</scp> A<scp>MINO</scp> A<scp>CID</scp> M<scp>ETABOLISM</scp> D<scp>URING AND</scp> A<scp>FTER</scp> E<scp>XERCISE AND THE</scp> E<scp>FFECTS OF</scp> N<scp>UTRITION</scp>

Michael J. Rennie et al. · Annual Review of Nutrition · 2000

DOI 10.1146/annurev.nutr.20.1.457

narrative_reviewCited 329×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →