Acute use of CurraNZ improves 5K running performance up to 5.7%

    on April 26, 2024


    A new acute dosing study has revealed that three capsules of CurraNZ® New Zealand Blackcurrant Extract improves 5Km running performance by up to 5.7%, which is being described as 'impressive' by running experts.

    On average, runners participating in the double-blind randomised cross over design study ran 3% faster - or 38 seconds - with 900mg of the berry extract.

    The University of Chester study, performed in 16 trained male runners and triathletes, tested the effect of three capsules of CurraNZ blackcurrant extract (900mg / 315mg anthocyanin) taken two hours before the 5km treadmill test. Findings showed: 

    • Faster completion times in 14 of the 16 participants
    • Average improvements of 3% (38 seconds), compared to placebo
    • 11 of the 16 participants improved by over 14.25 seconds (the typical variation in 5km running time in trained runners)

    US running expert Dr. Stefanie Flippin, (left) says the gains are ‘impressive’, likening them to improvements normally seen after a full season of well-structured training.

    The professional runner and coach says: "An average improvement of 38 seconds over 5km is enormous.

    “Faster completion times over shorter distances such as this are harder to achieve and require months – sometimes years – of training.”

    Dr Flippin, one of the fastest female ultra-runners in North America, believes the supplement offers a practical, cost-effective advantage to athletes.

    “When added to a nutritious diet, runners can optimise their race preparation by taking one dose of three capsules of blackcurrant extract, offering athletes a simple approach to achieving meaningful performance improvements to 5km race times."

    Dr Samantha Moss, Senior Lecturer in Physiology and Sports Sciences at the University of Chester, who led the study, said: “We were surprised to see the differences in running times between the conditions.

    "As part of our analysis, we calculated an effect size (d) value which allows us to interpret how meaningful performance changes are. In our study, we observed a small meaningful effect (d=0.23) of blackcurrant extract on time-trial performance.

    “The novelty is that New Zealand blackcurrant can be used as a performance enhancing aid on an acute basis, which may suit a lot of recreational athletes preparing for a race."

    Previous studies have shown that seven days intake of 1-2 capsules (300mg-600mg) of CurraNZ is required to improve cycling and running times. These improvements are linked to changes in cardiovascular and metabolic function. However, the faster running times in this study were achieved without significant changes to carbohydrate oxidation, fat oxidation, heart rate, blood lactate or rating of perceived exertion. 

    Dr Moss added: “Based on previous studies, we believe these changes might be due to an increase in blood flow, which can enhance lactate clearance. We measured lactate and saw slightly lower values in the blackcurrant condition, but the confidence intervals (i.e. range of estimates) were too big to say this could be one of the mechanisms responsible. Doing more work to assess the role of blackcurrant extract anthocyanin metabolite profiles might be useful for future work, considering that metabolites in similar compounds have been identified as possible drivers in altering blood flow.”


    1. Samantha L. Moss1, Edward Brindley1, Kevin Enright2, Jamie Highton1 & Richard Bott1 The effects of an acute dose of New Zealand blackcurrant extract on 5 km running performance Int J Sport Nutr Exerc Metab 2023