Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance

del Favero S, Roschel H, Artioli G, Ugrinowitsch C, Tricoli V, Costa A, Barroso R, Negrelli AL, Otaduy MC, da Costa Leite C, Lancha-Junior AH, Gualano B · Amino Acids

A head-to-head test that separates the two supplements: creatine raised muscle phosphorylcreatine and squat and bench-press power versus placebo, betaine raised neither, and adding betaine to creatine added nothing to creatine alone.

Population

Untrained subjects randomised to four arms for 10 days

Intervention

Betaine 2 g/day, creatine 20 g/day, both together, or placebo

Comparator

Placebo, and betaine against creatine head to head

Limitations

Untrained participants over only 10 days — short for a chronic betaine effect; muscle and performance endpoints only.