The study, published in the journal Medicine and Science in Sports and Exercise, shows for the first time that the drink and its high nitrate levels can be effective on athletic performance, said the University of Exeter researchers.
Beetroot juice is a natural source of nitrate, which the Exeter scientists have targeted as the active ingredient boosting the athlete’s performance.
According to the researchers, the nitrate has two physiological effects. Firstly, it widens blood vessels, reducing blood pressure and allowing more blood flow. Secondly, it affects muscle tissue, reducing the amount of oxygen needed by muscles during activity.
The combined effects have a significant impact on performing physical tasks, whether it involves low-intensity or high-intensity effort, claim the scientists.
Methodology and results
To conduct the study, nine club-level competitive male cyclists were asked to compete in time trials over 4km (2.5 miles) and 16.1km (10 miles).
All the riders were asked to do each time trial twice, drinking half a litre of beetroot juice before both trial.
For one trial, the cyclists consumed “normal” beetroot juice. For the other, they drank beetroot juice with the nitrate content removed– unknown to the participants.
The researchers monitored athletes’ VO2 levels (showing the amount of oxygen consumed) during exercise to ensure the cyclists worked at maximum effort on each occasion.
Results showed that when the cyclists drank beetroot juice with nitrate, they had a higher power output (measured in watts) for the same level of effort.
On average, riders were 11 seconds (2.8 per cent) quicker over the 4km distance and 45 seconds (2.7 per cent) faster over the 16.1km distance, after consuming the nitrate content.
The researchers claim the results indicate the nitrate supplementation allowed the cyclists’ muscles and cardio-vascular system to act more efficiently.
“The findings show an improvement in performance that, at competition level, could make a real difference – particularly in an event like the Tour de France where winning margins can be tight,” said lead author Andrew Jones.
The authors said beetroot juice also contains several other potentially metabolically active compounds that might influence the physiological responses to exercise, including betaine, antioxidants and polyphenols.
Source:Medicine and Science in Sports and Exercise
Acute Dietary Nitrate Supplementation Improves Cycling Time Trial Performance
Authors: K. E. Lansley, P.G. Winyard, S. J. Bailey, A. Vanhatalo, D. P. Wilkerson, J. R. Blackwell, M. Gilchrist, N. Benjamin and A. M. Jones