Effect of Acute Dietary Nitrate Supplementation on Arterial Blood Oxygen Saturation and Time Trial Performance During Acute Hypoxic Exposure in Male Cyclists and Triathletes

PURPOSE: To determine the effect of acute beetroot juice supplementation on blood pressure, exercising blood oxygen saturation, oxygen consumption, and exercise performance during acute hypoxic exposure (FIO2 ~13%). METHODS: Nine competitive male cyclists performed time trials on a cycle ergometer 2.5 hours following consumption of the three acute supplemental treatments: beetroot juice, nitrate depleted beetroot juice, and water. Blood pressure was measured before the supplement was ingested and pre and post- warm-up after supplement ingestion. Time to complete the time trial was measured as was oxygen saturation, oxygen consumption, and work rate during the time trial. RESULTS: Although collection times had a significant impact on some variables, no significant treatment effects were observed in blood pressure, completion times, work rates, oxygen consumption, cycling economy, or oxygen saturation. CONCLUSION: Acute beetroot juice supplementation did not affect blood pressure, exercising blood oxygen saturation, oxygen consumption, or time trial cycling performance during acute hypoxic exposure.