Vanhatalo, A., Fulford, J., Bailey, S. J., Winyard, P. G., & Jones, A. M. (2010). Effects of nitrate supplementation in normoxia and hypoxia. Presentation 24 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.

This study investigated the effects of dietary nitrate supplementation on muscle energy metabolism and blood flow under conditions of limited O2 availability (hypoxia). Moderately trained volunteers (N = 8) were tested in normoxia (21% O2 in balance N2) and in hypoxia (13% O2) following nitrate and placebo supplementation. The exercise protocol was a constant-work-rate bout of heavy intensity exercise and short bouts of high-intensity knee-extension exercise for the assessment of the [PCr] recovery time constant. Muscle metabolism was assessed during and after exercise using calibrated 31P-magnetic resonance spectroscopy and muscle blood flow and oxygenation were assessed using a range of non-invasive nuclear magnetic resonance techniques.

The PCr recovery time constant was reduced in hypoxia (29 ± 5 s) compared to normoxia (23 ± 5 s) and hypoxia following nitrate supplementation (24 ± 5 s).

Implication. Dietary nitrate supplementation could promote exercise tolerance in conditions where O2 delivery to the muscles is reduced.

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