Recent work by Jones and colleagues have demonstrated that ingestion of 0.5 L beetroot juice per d for 6 d reduces pulmonary oxygen uptake during submaximal exercise (Bailey, Fulford et al. 2009; Vanhatalo, Bailey et al. 2010; Lansley, Winyard et al. 2011) and lowers the ATP cost of muscle force production suggesting an enhanced contractile efficiency (Bailey, Winyard et al. 2010). This improvement in exercise efficiency was evident acutely (2.5 h) after ingestion of a single 0.5 L bolus of beetroot and persisted for 15 d when supplementation was continued (Vanhatalo, Bailey et al. 2010). Although the active ingredient in beetroot has been assumed to be nitrate, beetroot is rich in several other potentially metabolically-active compounds (e.g. polyphenols). To confirm whether the proposed cardiovascular and physiological benefits of beetroot juice are solely attributable to its high NO3- content, Jones and colleagues tested beetroot juice against nitrate-depleted beetroot juice. They verified their previous findings (Bailey, Fulford et al. 2009) by demonstrating a lowered O2 cost of submaximal exercise following ingestion of 0.5 L beetroot juice for 6 d when compared with the nitrate-depleted juice (Lansley, Winyard et al. 2011).