Effects of nitrate supplementation in trained and untrained muscle are modest with initial high plasma nitrite levels

Nitrate (NO3−) supplementation resulting in higher plasma nitrite (NO2−) is reported to lower resting mean arterial blood pressure (MAP) and oxygen uptake (VO2) during submaximal exercise in non‐athletic populations, whereas effects in general are absent in endurance‐trained individuals. To test whether physiologic effects of NO3− supplementation depend on local muscular training status or cardiovascular fitness, male endurance‐trained cyclists (CYC, n=9, VO2‐max: 64±3 mL/min/kg; mean±SD) and recreational active subjects serving as a control group (CON, n=8, 46±3 mL/min/kg), acutely consumed nitrate‐rich beetroot juice ([NO3−] ~9 mmol) (NIT) or placebo (PLA) with assessment of resting MAP and energy expenditure during moderate intensity (~50% VO2‐max) and incremental leg cycling (LEG‐ex) and arm‐cranking exercise (ARM‐ex). NIT increased (P