Dietary Nitrate Does Not Enhance Running Performance in Elite Cross-Country Skiers

• Autores: Oliver Peacock, Øyvind Sandbakk, Arnt Erik Tjonna, Philip E. James, Ulrik Wisløff, Christian Cook, Boye Welde, Keith Stokes, Nikolai Bohlke, Alan A. Smith
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 44, Nº. 11, 2012, págs. 2213-2219
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Dialnet Métricas: 1 Cita
• Resumen

  • AB Purpose: The objective of this study is to examine the effects of acute ingestion of dietary nitrate on endurance running performance in highly trained cross-country skiers. Dietary nitrate has been shown to reduce the oxygen cost of submaximal exercise and improve tolerance of high-intensity exercise, but it is not known if this holds true for highly trained endurance athletes. Methods: Ten male junior cross-country skiers (V[spacing dot above]O2max [almost equal to] 70 mL[middle dot]kg-1[middle dot]min-1) each completed two trials in a randomized, double-blind design. Participants ingested potassium nitrate (614-mg nitrate) or a nitrate-free placebo 2.5 h before two 5-min submaximal tests on a treadmill at 10 km[middle dot]h-1 ([almost equal to]55% of V[spacing dot above]O2max) and 14 km[middle dot]h-1 ([almost equal to]75% of V[spacing dot above]O2max), followed by a 5-km running time trial on an indoor track. Results: Plasma nitrite concentrations were higher after nitrate supplementation (325 +/- 95 nmol[middle dot]L-1) compared with placebo (143 +/- 59 nmol[middle dot]L-1, P < 0.001). There was no significant difference in 5-km time-trial performance between nitrate (1005 +/- 53 s) and placebo treatments (996 +/- 49 s, P = 0.12). The oxygen cost of submaximal running was not significantly different between placebo and nitrate trials at 10 km[middle dot]h-1 (both 2.84 +/- 0.34 L[middle dot]min-1) and 14 km[middle dot]h-1 (3.89 +/- 0.39 vs. 3.77 +/- 0.62 L[middle dot]min-1). Conclusions: Acute ingestion of dietary nitrate may not represent an effective strategy for reducing the oxygen cost of submaximal exercise or for enhancing endurance exercise performance in highly trained cross-country skiers. (C)2012The American College of Sports Medicine