Effects of Chronic Ingestion of L-arginine alpha ketoglutarate Combined With Creatine monohydrate on Anaerobic Performance in Strength-Trained Athletes

Abstract

There has been a vast growth in the use of ‘pre’ workout nutritional aids for sports performance over the past decade, particularly those containing single use amino acids such as L-arginine. There are many purported physiological benefits to suggest combination of L-arginine with creatine will expedite a greater performance, however exact mechanisms are equivocal and evidence suggesting an actual performance benefit are lacking. PURPOSE: To determine the effect of L-arginine alpha ketoglutarate (AAKG) on total body mass, fat free mass, peripheral blood flow (ml.100ml-1.min-1), isometric bench press and half squat, countermovement jump and peak power output in a single anaerobic Wingate. Further investigation into additive effects of creatine monohydrate (Cr) is undertaken where warranted. METHOD: Strength trained individuals (n = 24, Age: 24.5 ± 4.9 years; Height: 179.2 ± 8.1 cm; Weight: 77.1 ± 10.3 kg) were randomly assigned in a double blind manner either: (1) AAKG combined with Cr; (2) AAKG combined with a matched cornflour placebo (PLA); (3) Matched cornflour PLA alone, or (4) Control (CONT) across an 8 week intervention. Participants’ anthropometric measures, peripheral blood flow, isometric strength and power were tested. To minimise dietary covariance, subjects completed weekly nutritional assessments to maintain dietary consistency. RESULTS: Total body mass (TBM) was not significantly different at any point during the trial, overall TBM from baseline to week 8 was not significantly altered between any group (AAKG + Cr: 1.0 ± 0.7 kg, AAKG + PLA: 0.4 ± 0.5 kg, PLA: -0.1 ± 0.5 kg and CONT: 0.2 ± 0.1 kg; P > 0.05). Similarly, fat free mass (FFM) showed no significant weekly change and no significant overall difference from baseline to week 8 (AAKG + Cr: 1.3 ± 0.8 kg, AAKG + PLA: 0.3 ± 0.6 kg, PLA: -0.4 ± 0.5 kg and CONT: -0.5 ± 0.4 kg; P > 0.05). Blood flow PRE (AAKG + Cr: 0.35 ± 0.29 ml.100ml-1.min-1, AAKG + PLA: -0.07 ± 0.21 ml.100ml-1.min-1, PLA: 0.08 ± 0.12 ml.100ml-1.min-1 and CONT: 0.27 ± 0.17 ml.100ml-1.min-1) INTER (AAKG + Cr: 0.10 ± 0.29 ml.100ml-1.min-1, AAKG + PLA: -0.03 ± 0.25 ml.100ml-1.min-1, PLA: 0.04 ± 0.10 ml.100ml-1.min-1 and CONT: 0.30 ± 0.22 ml.100ml-1.min-1) and POST (AAKG + Cr: 0.19 ± 0.32 ml.100ml-1.min-1, AAKG + PLA: -0.11 ± 0.22 ml.100ml-1.min-1, PLA: 0.12 ± 0.09 ml.100ml-1.min-1 and CONT: 0.32 ± 0.14 ml.100ml-1.min-1) showed no significant difference at any point (P > 0.05). Isometric bench press demonstrated significant differences between AAKG + Cr and CONT only (83.28 ± 20.68 N and 15.51 ± 6.35 N respectively, P = 0.026) no significant differences between any other groups (AAKG + PLA: 48.33 ± 15.76 N and PLA: 26.63 ± 15.24 N, P > 0.05). In contrast isometric squat showed no significant differences at any point (AAKG + Cr: 117.50 ± 59.72 N, AAKG + PLA: 95.33 ± 27.27 N, PLA: 33.39 ± 47.88 N and CONT: -0.34 ± 9.48 N, P > 0.05). In addition there was no significant difference between any of the power variables at any stage throughout the trial, countermovement jump (AAKG + Cr: 1.43 ± 0.72 cm, AAKG + PLA: 1.47 ± 0.97cm, PLA: -0.53 ± 2.23 cm and CONT: -2.41 ± 1.84 cm, P > 0.05) and peak wingate trial (AAKG + Cr: 23.92 ± 9.40 W, AAKG + PLA: 16.92 ± 16.80 W, PLA: -0.58 ± 8.53 W and CONT: 5.25 ± 2.38 W, P > 0.05). CONCLUSION: There was no significant difference between the majority of the variables at any stage throughout the trial, the only significant difference was in isometric bench press between AAKG + Cr and CONT. This would suggest that the combination of L-arginine alpha ketoglutarate and Creatine monohydrate might only lead to limited improvements in strength gains over those gained without supplementation.