RESUMO
BACKGROUND: Recent studies have suggested that alpha glycerylphosphorylcholine (A-GPC) may be an effective ergogenic aid. The present study was designed to assess the efficacy of two doses of A-GPC in comparison to placebo and caffeine for increasing countermovement jump performance, isometric strength, and psychomotor function. METHODS: Forty-eight healthy, college aged males volunteered for the present study and underwent baseline assessment of countermovement jump (CMJ), isometric mid thigh pull (IMTP), upper body isometric strength test (UBIST), and psychomotor vigilance (PVT). Following this assessment participants were randomly assigned to groups consisting of 500 mg A-GPC, 250 mg A-GPC, 200 mg Caffeine or Placebo taken daily. Blood samples were collected 1 h and 2 h post initial dose to quantify serum free choline and thyroid stimulating hormone then subjects returned after 7 days of supplementation to repeat CMJ, IMTP, UBIST and PVT. RESULTS: No differences were noted between groups for IMTP, UBIST or PVT performance. Serum free choline was found to be elevated in the two A-GPC groups as compared to placebo (132% and 59% respectively). Serum TSH was found to be significantly depressed in the 500 mg A-GPC group compared to other treatments (p < 0.04). Group differences were noted for maximum velocity and maximum mechanical power on the CMJ (p < 0.05) with the 250 mg A-GPC group demonstrating the greatest improvements in result. CONCLUSIONS: Based upon this evidence, and previous evidence regarding A-GPC, it should be considered as an emerging ergogenic supplement.