One of the big trends in the supplement industry recently has been the introduction of nitrates into everything from amino acid products such as VPX’s Power Shock Amino and creatine such as SAN’s CM2 Nitrate. Anecdotal reports of improved muscle endurance and better pumps have been encouraging but to date there is relatively little research on the performance enhancing benefits of nitrates in a double-blind study. That makes a recent study published on nitrates fascinating.
Would the participants be able to show benefits by consuming nitrates that measured up in terms of real world performance?
A group at the University of Exeter in Great Britain headed by Lansley (1) investigated the effects
of nitrate supplementation on performance during simulated competition. As well as measuring markers related to performance such as power output and VO2 max, this group also measured performance during 4 and 16km time trials.
To help ensure an accurate result, the group of competitive male cyclists all performed the time trials in advance several times to ensure that they were familiar with the course and after five trials (without any supplementation), their performance between trials differed by less than 1%. It is safe to say that their performance was consistent then.
The subjects were assigned to a randomised, crossover design to consume 500ml of beetroot juice (containing approximately 6.2mmol of nitrate) or 500ml of beetroot juice where the nitrates were depleted using an ion resin to remove them. The participants would be unaware of which was which as they looked and tasted identical.
Can beetroot juice really produce a measurable benefit you ask?
Yes, based on this study with the group consuming the nitrate rich beetroot juice showing elevated plasma (which explains the pumps bodybuilders who use nitrates report) compared to placebo (PL = 241 ± 125 vs BR = 575 ± 199 nM) as well as greatly increased power output in the nitrate containing group (PL = 279 ± 51 vs BR = 292 ± 44 W). VO2 max was not statistically different between the two groups.
What about the effect on time trial performance over the two distances? Increases in power output and plasma are only useful to the extent they increase performance (although those who train purely for muscle pumps may disagree with this point.
The nitrate group increased their 4km performance by 2.8% (PL = 6.45 ± 0.42 vs BR = 6.27 ± 0.35 min) and on their 16km time trial by 2.7% (PL = 27.7 ± 2.1 vs BR = 26.9 ± 1.8 min, P < 0.01).
This study supports the reports presented by bodybuilders supporting the effectiveness of nitrate supplementation for increasing blood plasma levels, power output and performance in trained athletes.
Lansley et al (Acute dietary nitrate supplementation improves cycling time trial performance) Med Sci Sports Exerc. 2011 Jun;43(6):1125-31.
Author: Reggie Johal
© 2012, Reggie Johal. All rights reserved.