Influence of beetroot juice supplementation on intermittent exercise performance.

Lee J Wylie,James Kelly,James R Blackwell,Anni Vanhatalo,Andrew M Jones,Stephen J Bailey

doi:10.1007/s00421-015-3296-4

Abstract

PurposeThis study tested the hypothesis that nitrate (NO3−) supplementation would improve performance during high-intensity intermittent exercise featuring different work and recovery intervals. MethodTen male team-sport players completed high-intensity intermittent cycling tests during separate 5-day supplementation periods with NO3−-rich beetroot juice (BR; 8.2 mmol NO3− day−1) and NO3−-depleted beetroot juice (PL; 0.08 mmol NO3− day−1). Subjects completed: twenty-four 6-s all-out sprints interspersed with 24 s of recovery (24 × 6-s); seven 30-s all-out sprints interspersed with 240 s of recovery (7 × 30-s); and six 60-s self-paced maximal efforts interspersed with 60 s of recovery (6 × 60-s); on days 3, 4, and 5 of supplementation, respectively.ResultPlasma [NO2−] was 237 % greater in the BR trials. Mean power output was significantly greater with BR relative to PL in the 24 × 6-s protocol (568 ± 136 vs. 539 ± 136 W; P < 0.05), but not during the 7 × 30-s (558 ± 95 vs. 562 ± 94 W) or 6 × 60-s (374 ± 57 vs. 375 ± 59 W) protocols (P > 0.05). The increase in blood [lactate] across the 24 × 6-s and 7 × 30-s protocols was greater with BR (P < 0.05), but was not different in the 6 × 60-s protocol (P > 0.05).ConclusionBR might be ergogenic during repeated bouts of short-duration maximal-intensity exercise interspersed with short recovery periods, but not necessarily during longer duration intervals or when a longer recovery duration is applied. These findings suggest that BR might have implications for performance enhancement during some types of intermittent exercise.

Highlights

Nitric oxide (NO) is a multi-functional physiological signaling molecule that can be endogenously derived fromEur J Appl Physiol (2016) 116:415–425 the oxygen (O2)-dependent catabolism of l-arginine in a reaction catalyzed by the NO synthase (NOS) enzymes (Stamler and Meissner 2001), or from the O2-independent reduction of nitrite (NO2−) by numerous NO2− reductases (Lundberg and Weitzberg 2009)
The principal original finding of this study was that shortterm supplementation with beetroot juice (BR) significantly improved mean power output during 24 6-s all-out sprints interspersed with 24 s of recovery but not during protocols comprising seven 30-s all-out sprint efforts interspersed with 4 min of recovery or six 60-s self-paced maximal efforts interspersed with 60 s of recovery
BR was especially effective in improving MPOmean in the early part of the 24 × 6-s protocol, with the difference between conditions being significantly different in the first 6 but not the subsequent 18 sprints

Summary

Introduction

Nitric oxide (NO) is a multi-functional physiological signaling molecule that can be endogenously derived fromEur J Appl Physiol (2016) 116:415–425 the oxygen (O2)-dependent catabolism of l-arginine in a reaction catalyzed by the NO synthase (NOS) enzymes (Stamler and Meissner 2001), or from the O2-independent reduction of nitrite (NO2−) by numerous NO2− reductases (Lundberg and Weitzberg 2009). Fatigue development during high-intensity intermittent exercise is linked, in part, to the decline in muscle phosphocreatine concentration [PCr] (Fulford et al 2013; Gaitanos et al 1993), whereas recovery of intermittent exercise performance is linked to muscle PCr resynthesis (Bogdanis et al 1995, 1996; Mendez-Villanueva et al 2012). The increased perfusion and oxygenation of type II muscle that has been reported following NO3− supplementation (Ferguson et al 2013, 2015) might facilitate the O2-dependent recovery of PCr (Trump et al 1996; Vanhatalo et al 2011) in the type II muscle fibers that are preferentially recruited during highintensity intermittent exercise (Essén 1978; Green 1978; Krustrup et al 2004, 2009; Thomson et al 1979). Supplementation with NO3− has been reported to: enhance calcium handling and augment the rate of force development in type II muscle fibers (Hernández et al 2012); and to increase force production (Coggan et al 2015; Haider and Folland 2014) and attenuate fatigue development at high muscle contraction frequencies (Bailey et al 2015)

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