High dose Nitrate ingestion does not improve 40 km cycling time trial performance in trained cyclists

This study evaluated the chronic effects of nitrate (NO3-) ingestion over three days, on 40 km TT performance in 11trained cyclists (VO2max: 60.8 +/- 7.4 ml.kg(-1).min(-1); age: 36 +/- 9 years; height: 1.80 +/- 0.06 m; body mass: 87.2 +/- 12.0 kg). Utilising a double-blind randomised cross-over design, participants completed three 40 km TT on a Velotron (R) ergometer following the ingestion of either a 140 ml of "BEET It sport (R)" NO3- shot containing 12.8 mmol or 800 mg of NO3-, a placebo drink or nothing (control). Performance, oxygen consumption (VO2), blood bicarbonate (HCO3-), pH and lactate (BLa) and ratings of perceived exertion (RPE) were measured every 10 km throughout the TT. The present findings show that NO3- ingestion had no effect on TT performance (NO3-: 4098.0 +/- 209.8 vs. Placebo: 4161.9 +/- 263.3 s, p = 0.296, ES = 0.11), or VO2 (p = 0.253, ES = 0.13). Similarly, blood lactate and RPE were also unaffected by the experimental conditions (p = 0.522, ES = 0.06; p = 0.085, ES = 0.30) respectively. Therefore, these results suggest that a high dose of NO3- over three days has limited efficacy as an ergogenic aid for 40 km TT cycling performance in trained cyclists.