The effects of an acute dose of New Zealand blackcurrant extract on 5-km running performance

Abstract

This study investigated the effects of an acute dose (900 mg) of New Zealand Blackcurrant (NZBC) extract on 5 km running performance, alongside associated physiological and metabolic responses. Sixteen trained male runners (age 26 ± 5 years, stature 173.4 ± 7.3 cm, body mass, 73.7 ± 6.9 kg, V̇O2max 55.4 ± 6.1 ml.kg-1.min-1) ingested either capsules containing NZBC extract (3 x 300 mg CurraNZTM, 315 mg anthocyanins) or a matched placebo (3 x 300 mg gluten free flour) 2 hours before exercise in a double-blind, randomised, crossover design. Performance time, physiological, and metabolic responses were assessed in a 5-km time-trial, preceded by 10 min exercise at the lactate threshold on a treadmill. NZBC extract did not alter the physiological or metabolic responses to exercise at the lactate threshold (V̇O2, RER, V̇E, carbohydrate oxidation, fat oxidation, heart rate, blood lactate or Rating of Perceived Exertion, P>0.05). The 5-km time-trial was completed in a faster time in the NZBC extract condition compared to placebo (NZBC: 1308.96 ± 122.36 s, Placebo: 1346.33 ± 124.44, P=0.001, d=-0.23, CI range=-0.46 to 0.00 s). No differences in physiological or metabolic responses were apparent between conditions for the 5-km time-trial (P>0.05). Ingesting 900 mg of NZBC extract as an acute dose improves performance in trained male runners without altering physiological or metabolic responses to exercise. Further research is needed to assess a wider range of possible mechanisms (e.g., cardiovascular function, metabolite profiles) to advance insight into improved performance following supplementation.