Comparative Effects of Guanidinoacetic Acid and Creatine on Body Composition, Muscle Strength, and Protein Metabolism Biomarkers in Older Adults: A Randomized Exploratory Pilot Trial

Resumen del estudio

that remained within physiological reference ranges. Serum IGF-1 concentrations were below the assay detection limit in most participants, precluding evaluation of the GH-IGF-1 axis. No adverse events were reported, and compliance exceeded 97% in both groups. In this exploratory pilot trial conducted without structured exercise, GAA supplementation was associated with numerically greater improvements in muscle strength and several muscle-related indices compared with creatine; however, these findings are preliminary and hypothesis-generating and require confirmation in adequately powered trials targeting sarcopenia.