Creatine, arginine [alpha]-ketoglutarate, amino acids, and medium-chain triglycerides and endurance and performance.

Creatine (Cr) supplementation increases muscle mass, strength, and power. Arginine [alpha]-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. [ABSTRACT FROM AUTHOR]