INTRODUCTION TO PERFORMANCE
The key factors that determine successful performance within endurance sports can be classified as:
1) maximal oxygen uptake (VO2 max),
2) lactate threshold and
3) exercise economy/efficiency
[1]Economy of motion (known as exercise economy during running and efficiency during cycling) relates to the amount of oxygen required to produce a given running speed or cycling power output and, in individuals with similar performance characteristics (i.e. VO2 max and lactate threshold), is a strong predictor of performance[2].
In essence, those who can expend less energy and use less oxygen at higher workloads are likely to perform better.
THE ROLE OF NITRATES
Given the importance of exercise economy/efficiency for performance, nutritional strategies that have the ability to reduce the oxygen cost of exercise have gained increased popularity over recent years.
With this in mind, studies testing the effects of nitrate supplementation have begun to stack up and, when taken together, have collectively concluded that supplementation lowers the oxygen demand of exercise and improves performance across a range of endurance events[3]. Ingested nitrates are reduced to nitrite and nitric oxide on the tongue, in the stomach, within circulation and in the muscle, and, as nitric oxide is important in several processes that may support or enhance exercise performance, it is perhaps this nitrate-to-nitrite-to-nitric oxide journey that is crucial when considering the performance enhancing capacity of nitrate supplementation[4]. Indeed, the increased bioavailability of nitric oxide subsequently enhances the efficiency of muscle contraction and energy production within the mitochondria and, due to its vasodilatory properties, also enhances blood flow to the exercising muscle. Collectively, the combination of such factors contributes to a 5% reduction in the oxygen demand during submaximal exercise[4].
