Influence of nitrate supplementation on VO2 kinetics and endurance of elite cyclists

Authors

  • P. M. Christensen,

    1. Copenhagen Muscle Research Centre, Department of Exercise and Sport Sciences, Section of Human Physiology, University of Copenhagen, Copenhagen, Denmark
    2. Team Danmark (Danish Elite sports organization, Copenhagen, Denmark
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  • M. Nyberg,

    1. Copenhagen Muscle Research Centre, Department of Exercise and Sport Sciences, Section of Human Physiology, University of Copenhagen, Copenhagen, Denmark
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  • J. Bangsbo

    Corresponding author
    • Copenhagen Muscle Research Centre, Department of Exercise and Sport Sciences, Section of Human Physiology, University of Copenhagen, Copenhagen, Denmark
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Corresponding author: Jens Bangsbo, Department of Exercise and Sport Sciences, August Krogh Building, Universitetsparken 13, DK-2100 Copenhagen Ø, Denmark. Tel: +45 35 32 16 22, Fax: +45 35 32 16 00, E-mail:jbangsbo@ifi.ku.dk

Abstract

The present study examined if an elevated nitrate intake would improve VO2 kinetics, endurance, and repeated sprint capacity in elite endurance athletes.

Ten highly trained cyclists (72 ± 4 mL O2/kg/min, mean ± standard deviation) underwent testing for VO2 kinetics (3 × 6 min at 298 ± 28 W), endurance (120 min preload followed by a 400-kcal time trial), and repeated sprint capacity (6 × 20 s sprints, recovery 100 s) during two 6-day periods in randomized order with a daily ingestion of either 0.5 L beetroot (BR) juice to increase nitrate levels or a 0.5 L placebo (PLA) drink with blackcurrant juice. Plasma NOx (nitrate + nitrite) levels were higher (P < 0.01) in BR (147 ± 102 and 159 ± 103 μM after 4 and 6 days of beverage intake, respectively) compared with PLA (41 ± 10 and 40 ± 7 μM). VO2 kinetics and exercise economy were the same in BR and PLA. Time-trial performance was similar with an average completion time of 18:20 and 18:37 min:s in BR and PLA, respectively, with average power outputs of 290 ± 43 W in BR and 285 ± 44 W in PLA. Peak and mean power during repeated sprinting were similar in BR and PLA.

In contrast to observations in moderately trained subjects intake of BR juice had no effect on VO2 kinetics and performance in elite cyclists.

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