Effect of one-week New Zealand blackcurrant extract on rowing performance and cognitive function in National team male rowers

Res Sports Med. 2025 May-Jun;33(3):266-279. doi: 10.1080/15438627.2025.2455971. Epub 2025 Jan 26.

Abstract

This research investigated the impact of New Zealand blackcurrant (NZBC) on 2000-meter rowing ergometer performance and cognitive abilities. Nine trained male rowers from Iran's national team participated in a double-blind, placebo-controlled crossover study, undergoing three sessions with NZBC (600 mg∙day-1), placebo (PL), and control (CL) treatments over seven days, followed by a 14-day washout period. Participants completed a 2000-meter ergometer test provided self-reported ratings of perceived exertion (RPE) and completed a cognitive function assessment five minutes following the rowing exercise. Findings indicated no significant ergogenic benefits from NZBC supplementation (420 ± 12 s) compared to PL (424 ± 15 s) and CL (423 ± 14 s), despite showing a minimal effect size (Cohen's d = 0.23). Six subjects had negligible enhancements in performance. No changes were seen in cognitive function or RPE (p > 0.05). A seven-day regimen of NZBC did not enhance rowing performance, cognitive function, or RPE.

Keywords: Endurance exercise; ergogenic aids; polyphenols; rowers.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Athletic Performance* / physiology
  • Athletic Performance* / psychology
  • Cognition* / drug effects
  • Cross-Over Studies
  • Dietary Supplements*
  • Double-Blind Method
  • Exercise Test
  • Humans
  • Male
  • New Zealand
  • Performance-Enhancing Substances* / administration & dosage
  • Performance-Enhancing Substances* / pharmacology
  • Physical Exertion / drug effects
  • Plant Extracts* / administration & dosage
  • Plant Extracts* / pharmacology
  • Ribes* / chemistry
  • Water Sports* / physiology
  • Water Sports* / psychology
  • Young Adult

Substances

  • Plant Extracts
  • Performance-Enhancing Substances