Beetroot’s burgeoning reputation as a super-vegetable has been enhanced further following yet another study linking the nitrate contained in its juice with improved athletic performance.
Results from research by the University of Exeter, and published in the journal Medicine and Science in Sports and Exercise, suggests drinking nitrate-rich beetroot juice enables competitive-level cyclists to cut down the time it takes to ride a given distance.
For the study, nine club-level competitive male cyclists were asked to compete in time trials over 2.5 miles and 10 miles. All the riders were asked to do each time trial twice. Each time they drank half a liter of beetroot juice beforehand. On one occasion they had normal beetroot juice, on the other occasion—unbeknown to the participants—the beetroot juice had the nitrate removed.
To ensure the cyclists worked at maximum effort on each occasion, the researchers monitored the athletes’ VO2 levels during the exercise, a test that shows the amount of oxygen consumed.
The results indicated that when the cyclists drank ordinary beetroot juice they had a higher power output (measured in watts) for the same level of effort—suggesting their muscles and cardio-vascular system were operating more efficiently.
On average, these riders were 11 seconds (2.8%) quicker over the 2.5 mile distance and 45 seconds (2.7%) faster over the 10 mile distance. It's an eye-opening result in a sport in which the differences in performances at the elite level are measured in tenths of a percent.
Professor Andrew Jones from the University of Exeter, and lead author on the research, said: “This is the first time we've studied the effects of beetroot juice, and the high nitrate levels found in it, on simulated competition. 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.”
Beetroot juice is a natural source of nitrate, which is believed to have two physiological effects that could benefit athletes. Firstly, it widens blood vessels, reducing blood pressure and allowing more blood flow. Secondly, it reduces the amount of oxygen needed by muscles during activity. The combination of these effects is thought to have a significant impact on the performance of physical tasks, involving both low and high intensity effort.
A previous study by the University of Exeter suggested that the nitrate in beetroot juice could boost stamina levels and help athletes compete for longer.
Journal Reference: Katherine E. Lansley et al, Acute Dietary Nitrate Supplementation Improves Cycling Time Trial Performance. Medicine & Science in Sports & Exercise, 2011; 43 (6): 1125 DOI: 10.1249/MSS.0b013e31821597b4