Effects of sodium phosphate and beetroot juice supplementation on repeated-sprint ability in females

Abstract

SP improved RSA in team-sport, female athletes when fresh (set 1) and during the later sets of a STGC (sets 2 and 3). Specifically, total and best sprint times were faster after SP compared with placebo and BJ.

No effect of beetroot juice supplementation on exercise economy and performance in recreationally active females despite increased torque production

“…Lastly, three studies have been performed in elite female populations in which two demonstrate no beneficial effect with acute BRJ supplementation (Buck et al. ; Glaister et al. ) and one study shows chronic BRJ supplementation to improve aerobic and sprint swimming performance (Pospieszna et al.…”

“…Although intriguing, these findings warranted a more robust and rigorous examination of the effects of BRJ supplementation on submaximal exercise economy. Lastly, three studies have been performed in elite female populations in which two demonstrate no beneficial effect with acute BRJ supplementation (Buck et al 2015;Glaister et al 2015) and one study shows chronic BRJ supplementation to improve aerobic and sprint swimming performance (Pospieszna et al 2016). Although our submaximal exercise economy data demonstrate no effect of BRJ supplementation and are in contrast to other studies in non-elite females (Bond et al 2014;Rienks et al 2015), we believe the data presented in this study provides a strong, well-controlled and comprehensive investigation of acute and chronic BRJ supplementation on exercise economy and TT performance in recreationally active females.…”

Practical Issues in Evidence-Based Use of Performance Supplements: Supplement Interactions, Repeated Use and Individual Responses

“…Using an inference based statistical approach, caffeine would likely (88%) improve TT performance and very likely (99%) enhance power output (caffeine vs. lacebo), with a small reduction in this effect when combined with BJ. BJ was very unlikely (0%) to have any positive effect on performanceNitrate/beetroot Juice and phosphate Buck et al [41]Recreationally trained team sport athletes ( n  = 13 F)Crossover design to produce BJ, phosphate, combined, and placebo trials6 mmol nitrate in BJ @ 2 h pre-exercise and/or 6 days @ 50 mg/kg/day FFM sodium phosphate in split dosesWashout of 17 days between trialsTeam sport 6× 20 s sprints Undertaken @ 0, 30 and 60 around a 4 × 15 min simulated team game circuitNitrate: NoPhosphate: YesInteraction: independent mechanism with possibly counteractive effectCompared with placebo and BJ, phosphate trial produced faster total sprint time for first and second set of sprints and overall sprints (~5% improvement, p  < 0.05). Phosphate produced fastest sprint in set 1 and overall compared with placebo (~6% faster).…”

“…Other supplement combinations that have received some attention in the literature include the pairing of nitrate/beetroot juice with caffeine [39, 40] or phosphate [41]. In each case there has been a failure to see a benefit from the nitrate supplementation but an enhancement by the other performance supplement and a slight [39, 40] to apparent [41] reduction in the benefit of the combined supplementation protocol.…”

“…In each case there has been a failure to see a benefit from the nitrate supplementation but an enhancement by the other performance supplement and a slight [39, 40] to apparent [41] reduction in the benefit of the combined supplementation protocol. While the former may simply be a quirk of the statistical analysis in a small sample size, there may be some interaction that requires further investigation.…”