Background: Previous studies have provided observations on performance enhancement by intake of New Zealand blackcurrant (NZBC) extract, e.g. for 16.1 km ergometer cycling and intermittent high-intensity treadmill running. The effects of nutritional ergogenic aids on exercise performance may depend on the recruitment of muscle mass and the exercise-specific metabolic and physiological responses of an exercise modality. We examined the effects of 7-day intake of NZBC extract on 2000-m rowing performance.

Methods: Male indoor rowers from University teams (n=14, age: 21±2 years, height: 182±8 cm, mass: 81±14 kg, BMI: 24.3±2.9 kg·m-2, body fat: 14±4%, rowing V̇O2max: 53.7±10.2 ml·kg-1·min-1) volunteered. Participants were familiarized with two maximal efforts of 2000-m (drag factor 120, Concept2, Nottingham, United Kingdom). Testing for each participant was at the same time of day (10 were tested in the morning and 4 in the afternoon). Feedback during rowing was distance and stroke rate. Rowing time and stroke rate were recorded every 400-m sector. Heart rate during rowing was measured every 500-m sector in seven participants. Participants consumed capsulated 600 mg of NZBC extract (210 mg of anthocyanin per day) or placebo for 7 days (randomized, cross-over design). The final capsules were taken 2 hours before testing with intake of a slice of toast and water.

Results: There was no difference in the rowing time for each of the sectors (e.g. 0-400-m, placebo: 86.0±5.7, NZBC: 87.3±6.6 s) and total rowing time for the 2000-m between placebo (437.2±32.6 s) and NZBC (441.0±34.9 s) (P=0.13). There was no difference for average power output and average heart rate (placebo: 176±10, NZBC: 175±11 beats·min-1, P= 0.27). With NZBC, the average stroke rate was higher during the 2000-m rowing (placebo: 27±2, NZBC extract: 28±2 strokes·min-1, P= 0.003). Ten participants (71%) had a higher average stroke rate with intake of NZBC extract.

Conclusion: For 2000-m indoor rowing, anthocyanin-rich NZBC extract had no effect on the pacing strategy and the total rowing time. NZBC extract allowed a higher stroke rate. During rowing, stroke rate is linked with breathing frequency. Under the assumption that tidal volume did not change in our study, the increased ventilation with NZBC extract may be beneficial for longer distance rowing events. NZBC extract did not affect 2000 rowing performance in male indoor rowers notwithstanding an increased stroke rate.

Acknowlegdements: Supplementation was provided by Health Currancy Ltd (United Kingdom) and CurraNZ Ltd (New Zealand). Financial support for conference attendance was obtained from Blackcurrant New Zealand Inc. (New Zealand).