Creatine, Arginine AKG, AAs, and MCTs and Endurance and Performance

Creatine, Arginine α-Ketoglutarate, Amino Acids, and Medium-Chain Triglycerides and Endurance and Performance

Jonathan P. Little, Scott C. Forbes, Darren G. Candow, Stephen M. Cornish, Philip D. Chilibeck
IJSNEM, 18(5), October 2008, Vol. 18, Iss. 5

Abstract

Creatine (Cr) supplementation increases muscle mass, strength, and power. Arginine a-ketoglutarate (A-AKG) is a precursor for nitric oxide production and has the potential to improve blood flow and nutrient delivery (i.e., Cr) to muscles. This study compared a commercial dietary supplement of Cr, A-AKG, glutamine, taurine, branched-chain amino acids, and medium-chain triglycerides with Cr alone or placebo on exercise performance and body composition. Thirty-five men (~23 yr) were randomized to Cr + A-AKG (0.1 g · kg–1 · d–1 Cr + 0.075 g · kg–1 · d–1 A-AKG, n = 12), Cr (0.1 g · kg–1 · d–1, n = 11), or placebo (1 g · kg–1 · d–1 sucrose, n = 12) for 10 d. Body composition, muscle endurance (bench press), and peak and average power (Wingate tests) were measured before and after supplementation. Bench-press repetitions over 3 sets increased with Cr + A-AKG (30.9 ± 6.6 ± 34.9 ± 8.7 reps; p < .01) and Cr (27.6 ± 5.9 ± 31.0 ± 7.6 reps; p < .01), with no change for placebo (26.8 ± 5.0 ± 27.1 ± 6.3 reps). Peak power significantly increased in Cr + A-AKG (741 ± 112 ± 794 ± 92 W; p < .01), with no changes in Cr (722 ± 138 ± 730 ± 144 W) and placebo (696 ± 63 ± 705 ± 77 W). There were no differences in average power between groups over time. Only the Cr-only group increased total body mass (79.9 ± 13.0 ± 81.1 ± 13.8 kg; p < .01), with no significant changes in lean-tissue or fat mass. These results suggest that Cr alone and in combination with A-AKG improves upper body muscle endurance, and Cr + A-AKG supplementation improves peak power output on repeated Wingate tests.