Beetroot Juice Improves Endurance Performance

Introduction

While the thought of it ain’t too pleasant, drinking beetroot juice has recently been shown to improve cycling time trial performance over 4 km and 16.1 km. Why might that be? Well, it looks like the nitrate-rich beetroot juice enhances blood flow by increasing the diameter of blood vessels and thus enhancing oxygen delivery as well as making energy metabolism more efficient during high intensity endurance exercise.

The Research

Nine young competitive male cyclists (21 ± 4 years; 79.6 ± 9.7 kg; VO2max 56.0 ± 5.7 ml/kg/min) completed four time trials (TT) in a random order using a Computrainer system with each test separated by 48-72 hours:

  1. 4 km TT with the beetroot juice containing nitrate
  2. 4 km TT with the beetroot juice with the nitrate removed (placebo)
  3. 16.1 km TT with the beetroot juice containing nitrate
  4. 16.1 km TT with the beetroot juice with the nitrate removed (placebo)

The beetroot juice used was an organic commercial product produced in the UK but available here in Oz for a reasonable price – 750 ml bottle RRP is $5.50 and the 250 ml bottle $3.00. The cyclists turned up to the lab fresh having done no hard training in the previous 24 hours and eaten the same food and fluids leading up to drinking the juices before each TT in the lab. When they turned up at the lab and after drinking the juice, they had their blood levels of nitrite measured (the nitrate in the juice turns to nitrite that then becomes nitrous oxide (laughing gas) – a blood vessel dilator that makes the blood vessel wider and thus enhances blood flow). Over a period of 15 minutes, the cyclists drank 500 ml of the beetroot juice 2.5-2.75 hrs before doing each of the four TTs on four separate days at least two days apart. During the time between drinking of the juice and the TT, they drank only water and did no exercise. During each TT, power output (watts) and oxygen use were measured continuously.

 The Results

The beetroot juice significantly increased average power output during the 4-km TT by 2.8 % (292 ± 44 watts) compared to the placebo drink of beetroot juice with the nitrate removed chemically (279 ± 51 watts). During the 16.1-km TT, the beetroot juice with nitrate improved power output by 2.7% (247 ± 44 versus 233 ± 43). Each of the nine riders improved in both the TTs after taking the juice with nitrate in it – the normal beetroot juice!

 The So What?

 This British study strongly suggests the commercially-available beetroot juice improves TT performance in club level, sub-elite cyclists. They cautiously say that the study was done on club-level riders and the same effect may not be seen in high-performance riders. However, my feeling is why not give it a go. The word on the street is that Geelong Football Club )Premiers) and the Wallabies have used it!! Be warned though, your pee goes pink!!

 Source: Lansley, K.E. and others. (2011). Acute dietary nitrate supplementation improves cycling time trial performance. Medicine and Science in Sports and Exercise. 43(6): 1125-1131.