Beetroot Juice Does Not Enhance Supramaximal Intermittent Exercise Performance in Elite Endurance Athletes.

International audienceOBJECTIVE: Nitrate (NO)-rich beetroot juice (BR) is recognized as an ergogenic supplement that improves exercise tolerance during submaximal to maximal intensity exercise in recreational and competitive athletes. A recent study has investigated the effectiveness of BR on exercise performance during supramaximal intensity intermittent exercise (SIE) in Olympic-level track cyclists, but studies conducted in elite endurance athletes are scarce. The present study aimed to determine whether BR supplementation enhances the tolerance to SIE in elite endurance athletes.METHODS: Eleven elite endurance athletes (age: 21.7 ± 3.7 years, maximal oxygen uptake 71.1 ± 5.2 mL·kg·min) performed an SIE test until exhaustion following either a 3-day BR supplementation (340 mg/d) or a placebo (PL) supplementation (