Galvan, Elfego (2015-10). Acute and Chronic Analysis of the Safety and Efficacy of Dose Dependent Creatine Nitrate Supplementation and Exercise Performance. Doctoral Dissertation.
Thesis
Creatine monohydrate (CrM) and nitrate are popular supplements for improving exercise performance; yet they have not been investigated in combination. We performed two studies to determine the safety and exercise performance-characteristics of creatine nitrate (CrN) supplementation. In Study 1, 13 participants ingested 1.5 g CrN (CrN-L), 3 g CrN (CrN-H), 5 g CrM or a placebo (PL) in a crossover study to determine supplement safety. Hepatorenal and muscle enzymes, heart rate, blood pressure and side effects were measured before supplementation, 30 minutes after ingestion, and then hourly for 5 hours post-supplementation. In Study 2, 48 participants received the same CrN treatments vs. 3 g CrM in a double-blind, 28-day trial inclusive of a 7-day interim testing period and loading sequence (4 servings/d). Day-0 and day-28 measured bench press performance, Wingate testing and a 6x6-s bicycle ergometer sprints. Data were analyzed using a general linear model and results are reported as mean +- standard deviation or mean change +- 95% confidence interval (CI). Both studies yielded several significant, yet stochastic changes in blood markers that were not indicative of potential harm or consistent for any treatment group. Equally, all treatment groups reported a similar number of minimal side effects. In Study 2, there was a significant increase in plasma nitrates for both CrN groups by day-7, subsequently abating by day-28. Muscle creatine increased significantly by day-7 in the CrM and CrN-H groups, but decreased by day-28 for CrN-H. By day-28, there were significant increases in bench press lifting volume (kg) for all groups (PL, 126.6, 95% CI 26.3, 226.8; CrM, 194.1, 95% CI 89.0, 299.2; CrN-L, 118.3, 95% CI 26.1, 210.5; CrN-H, 267.2, 95% CI 175.0, 359.4, kg). Only the CrN-H group was significantly greater than PL (p<0.05). Similar findings were observed for bench press peak power (PL, 59.0, 95% CI 4.5, 113.4; CrM, 68.6, 95% CI 11.4, 125.8; CrN-L, 40.9, 95% CI -9.2, 91.0; CrN-H, 60.9, 95% CI 10.8, 111.1, Watts) and average power. Creatine nitrate was well-tolerated, demonstrated similar performance benefits to 3 g CrM, and was void of significant hemodynamics or blood enzymes changes associated with supplement safety.
