Blackcurrant for Rugby and Team Sports: What Repeated-Sprint Research Actually Shows
Late in a rugby match, the hard part is rarely the first sprint. You have already accelerated into space, chased a kick, stopped, changed direction, made a tackle, got back onside and gone again. Then the game asks for another hard effort.
That is where the most interesting New Zealand blackcurrant rugby performance research sits. The current evidence is not a simple story that blackcurrant makes a player faster. In several repeated-sprint and stop-start exercise studies, the more interesting signal is whether performance drops off less when hard efforts have to be repeated.
That distinction matters. A faster best sprint and less slowing across later sprints are not the same result. The first is about outright speed. The second is about what happens as repeated high-intensity work starts to bite.
For active customers looking at our NZ-grown Blackcurrant Skin Extract, that makes the ingredient worth a closer look. Human researchers have tested defined New Zealand blackcurrant preparations in rugby, football and intermittent-running settings, rather than only in broad wellness research. Those studies did not test our finished formula, so we keep the research finding and our product claim separate.
The rugby researchers asked players to sprint six times
A 2022 trial brought 13 male university rugby union players into a controlled testing setting and gave them a sequence of tasks designed to touch several physical qualities used in rugby.1
The first task is easy to picture. Each player ran six 35 m sprints, with only 10 seconds of rest between them. The researchers recorded the fastest sprint, the average across the six, and how much sprint times slowed as the set went on.
After that came an Illinois agility test, a seated medicine-ball throw and a handgrip-strength test. So this was not a study built around one favourable result. It asked whether the tested NZ blackcurrant extract changed speed, repeated speed, agility, upper-body power or grip strength across a short battery of rugby-relevant tasks.
The trial used a specific anthocyanin-rich NZ blackcurrant extract preparation in a randomised, placebo-controlled crossover design. That detail is important: the findings belong to the preparation and protocol that were actually tested.
The clearest result appeared near the end
The headline is not that the players suddenly became faster sprinters.
The fastest single 35 m sprint did not differ significantly between the blackcurrant and placebo conditions. In other words, the trial did not show that the tested blackcurrant preparation gave players a meaningfully faster best sprint.1
Average sprint time across the six runs leaned in a favourable direction, but the result was small and borderline rather than clearly significant. That is useful context because it stops a modest finding being turned into a sweeping speed claim.
The clearest result showed up on sprint six. With the tested NZ blackcurrant extract, the players slowed less on that final sprint than they did under placebo. That is the result worth remembering.
Picture the difference this way: if two players start the set at roughly the same level, the research question is not only who can produce the quickest isolated sprint. It is whether one condition changes how much performance fades after the legs have already been asked to go hard several times.
That is why blackcurrant repeated sprint performance is a more accurate way to discuss this study than saying blackcurrant boosts sprint speed. The result is about reduced slowing in a specific six-sprint test with a specific research extract. It is not proof of a match-day performance effect from our capsules.
Agility moved a little. Strength did not.
The rugby study also gives a useful reality check on how far the result can be stretched.
Average Illinois agility time was slightly faster with the tested extract, but again the difference was small and borderline. It is interesting, especially because the agility task came after the repeated sprints, but it is not strong evidence for claiming a broad improvement in rugby agility.1
The seated medicine-ball throw did not improve significantly. Handgrip strength did not improve significantly either.
That combination makes the rugby result more specific, not less useful. Something can look interesting for repeated running without improving every physical quality that matters on a rugby field. Speed, agility, strength, power, skill, contact ability and decision-making are different things.
The football study adds a training-status twist
An earlier football study used the same basic repeated-running idea: six 35 m sprints with short recovery. It included nine trained youth players from an English professional club and 15 recreationally active university-level football players.2
In the trained youth group, the tested NZ blackcurrant extract reduced slowing around sprint five. The recreational group did not show the same result.
That naturally raises a question: could training status change how someone responds?
Possibly, but we would not turn it into a rule. The groups were small, and one study cannot establish that trained athletes definitely benefit while recreational athletes do not. What it does show is that responses can differ between groups, even when the same repeated-sprint test is used.
For anyone reading blackcurrant football performance research, that nuance is useful. The effect was not universal, and the interesting outcome again appeared later in a repeated set rather than as a simple first-sprint speed boost.
Another team-sport test tells a similar, imperfect story
The Loughborough Intermittent Shuttle Test goes a step closer to the stop-start rhythm of field sport. It mixes maximal 15 m sprints with periods of moderate and higher-intensity running across repeated blocks, followed by a run to exhaustion.3
In that study, the tested NZ blackcurrant extract did not improve average sprint times within the blocks. It also did not significantly improve vertical-jump power or time to exhaustion.
But there was a more specific finding: the fastest sprint slowed less from the early block to the later block under the blackcurrant condition.
Again, the useful story is not simply that blackcurrant makes athletes faster. It is that some research on defined NZ blackcurrant preparations has found less drop-off across repeated high-intensity efforts, while other performance measures stayed unchanged.
What the 2026 review changes
Individual studies can be easy to overread, especially when participant numbers are small. A July 2026 systematic review gives us a better wide-angle view.4
The review included 21 randomised crossover trials of New Zealand blackcurrant supplementation. When the authors grouped results by exercise type, the largest pooled sport-performance signal was in intermittent and team-based exercise involving repeated high-intensity efforts. The pooled effect for that category was Cohen's d 0.66.
That number should not be turned into a percentage improvement. It is a standardised effect size used to combine results measured in different ways.
The review also kept the brakes on certainty. Sport-performance evidence was rated low certainty because the studies were generally small, exercise models varied, protocols differed and the estimates were imprecise. That is exactly why we prefer a measured claim: this is an interesting area of research, not a guarantee.
A 2024 repeated high-intensity running study adds another useful caution. In 16 active men, the average running response favoured the tested extract, but individual responses varied and were not consistently reproducible for everyone across repeated trials.5 The group average and the individual experience are not always the same thing.
If you want more background on the berry compounds behind this research, our guide to New Zealand blackcurrant anthocyanins explains the ingredient story without turning this article into a chemistry lesson. You can also browse our blackcurrant collection if you want to see the current Kiwi Superfoods options.
What this could mean for rugby, football, hockey and netball
Rugby and football have direct NZ blackcurrant research examples. Hockey and netball do not need to be claimed as proven for the movement pattern to feel familiar.
Across these sports, players repeatedly combine:
- acceleration
- hard running
- deceleration
- changes of direction
- brief recovery
- another hard effort
That is why the repeated-effort research is relevant to the conversation around blackcurrant team sports. Researchers have deliberately used exercise models where hard running has to be repeated rather than testing only one isolated sprint.
For rugby and football, we can point to direct studies. For hockey and netball, we would go no further than saying the stop-start movement pattern shares characteristics with the intermittent exercise models researchers have studied.
This is also where our Blackcurrant Skin Extract makes sense as an ingredient-led option for active customers. We use NZ-grown blackcurrant skin extract in a convenient capsule, but we do not claim the finished Kiwi Superfoods product has been clinically proven to improve match performance or repeated sprinting.
Our Product Is Simple. The Research Question Isn't.
We like keeping our blackcurrant option straightforward. Our Blackcurrant Skin Extract uses NZ-grown blackcurrant skin extract in capsule form, with added vitamin C. Each bottle contains 60 capsules, the current directions are two capsules daily, and the product is described as gluten free and vegan-friendly.
What makes the ingredient interesting to us is that defined New Zealand blackcurrant preparations have been tested in human rugby, football and high-intensity intermittent-running research. That gives us a factual reason to see NZ blackcurrant as worth considering for active customers who are interested in the ingredient and the evidence around it.
It does not mean every blackcurrant extract is interchangeable. The published performance trials used their own research preparations, including CurraNZ preparations in the studies discussed above. They did not test the finished Kiwi Superfoods formula.
So we keep the positive case simple: NZ blackcurrant has an unusually relevant body of repeated-running research for a food-derived ingredient, and our Blackcurrant Skin Extract offers a straightforward way to add NZ-grown blackcurrant skin extract to your day. We do not turn that into a promise of faster sprints, better agility, more strength, improved stamina, faster recovery or better match outcomes.
A quick safety note: if you are pregnant or breastfeeding, take prescription medicines, have a bleeding disorder or have surgery planned, check the label and get suitable professional advice before use. Our blackcurrant supplement safety guide covers those practical points in more detail.
If you compete, check more than the ingredient list
If you play in a drug-tested environment, supplement quality matters as much as the ingredient you are interested in.
New Zealand Rugby supports a food-first approach and warns that supplement use can create health, performance and anti-doping risks, including the risk of a prohibited substance being present or inaccurately labelled.6 World Rugby gives similar advice and tells athletes to assess whether a supplement is actually needed, research the manufacturer carefully, and consider independent batch testing for the specific batch used.7
Batch testing can reduce risk, but it cannot remove it completely. WADA does not approve supplements. We do not claim Kiwi Superfoods Blackcurrant Skin Extract is WADA approved, NZ Rugby approved, Informed Sport certified, independently batch tested or guaranteed safe for a drug-tested athlete.
If you are subject to testing, follow your current team process, speak with a sports dietitian or other qualified member of your performance team, and use the Sport Integrity Commission's current supplement decision-making guidance.8
Match performance and post-match recovery are different questions
Maintaining a measured exercise outcome during repeated efforts and recovering after a match are separate research questions. A study about sprint drop-off does not automatically answer how sore you will feel the next day, and recovery findings should not be used to claim better match performance.
If your main interest is soreness and post-exercise recovery, read our separate guide to blackcurrant extract and muscle recovery. We keep that topic separate so each article can answer one question properly.
Common questions
Does blackcurrant help rugby performance?
Some research on specific New Zealand blackcurrant extract preparations is promising for repeated high-intensity running in rugby-related tests, but it does not show that blackcurrant improves every part of rugby performance or that every product will produce the same result.
What did the New Zealand blackcurrant rugby study find?
In 13 male university rugby players, the tested NZ blackcurrant extract did not significantly improve the fastest 35 m sprint. The clearest significant sprint finding was less slowing on the sixth sprint of a six-sprint test, while average sprint and agility results were small or borderline.
Can blackcurrant help repeated sprint performance?
Several studies using defined NZ blackcurrant extracts have reported less slowing or favourable performance changes during repeated high-intensity running. The evidence is encouraging but still based on small studies with varied protocols, so it should not be treated as a guaranteed effect.
Does blackcurrant make your first sprint faster?
The rugby study did not show a significantly faster best 35 m sprint. Its more interesting result appeared later in the repeated-sprint set, which is why we describe the evidence as a repeated-effort story rather than a raw-speed claim.
Does blackcurrant improve agility, strength or power in rugby players?
In the 2022 rugby study, agility showed only a small, borderline difference. Seated medicine-ball performance and handgrip strength did not significantly improve, so the study does not support broad claims about better strength or power.
Does blackcurrant work differently in trained and recreational athletes?
One football study found reduced sprint slowing in trained youth players but not in the recreational group. That makes training status an interesting possibility, not a proven rule, because the groups were small and responses can vary between individuals.
Is Kiwi Superfoods Blackcurrant Skin Extract the same product used in rugby studies?
No. The published rugby and repeated-sprint studies used specific research preparations. They did not test the finished Kiwi Superfoods Blackcurrant Skin Extract formula, so we do not claim our capsules will reproduce those performance results.
Can competitive rugby players take blackcurrant supplements?
Competitive players should assess any supplement carefully. NZ Rugby, World Rugby and the Sport Integrity Commission all warn that supplements can carry anti-doping risk. If you may be tested, follow current team and Sport Integrity guidance and get qualified sports-nutrition advice before using a supplement.
Is blackcurrant performance research the same as recovery research?
No. Repeated-sprint or intermittent-running performance and post-exercise recovery are different outcomes. A result in one area should not be used as proof of a benefit in the other.
Next steps
If your interest in blackcurrant for rugby comes from the repeated-effort research, keep the key point in view: the evidence is more interesting for how performance changes across hard efforts than for a claim of instantly faster sprint speed.
For someone who specifically wants a straightforward NZ-grown blackcurrant skin extract capsule, our product is an easy place to start exploring. Follow the current label, keep your wider food and training base strong, and judge the product on how well it fits your own needs rather than expecting a guaranteed match-day result.
References
- Burnett PJM, Willems MET. Effects of New Zealand Blackcurrant Extract on Sequential Performance Testing in Male Rugby Union Players. Sports. 2022.
- Godwin C et al. Effect of New Zealand Blackcurrant Extract on Performance during the Running Based Anaerobic Sprint Test in Trained Youth and Recreationally Active Male Football Players. Sports. 2017.
- Williams D et al. Beneficial Effects of New Zealand Blackcurrant Extract on Maximal Sprint Speed during the Loughborough Intermittent Shuttle Test. Nutrients. 2018.
- Gholamian S, Ebrahimi S, Razmdideh A. Effect of New Zealand Blackcurrant Supplementation on Sports Performance: A Systematic Review. Current Developments in Nutrition. 2026.
- Perkins IC, Blacker SD, Willems MET. Individual Responses to Repeated Dosing with Anthocyanin-Rich New Zealand Blackcurrant Extract During High-Intensity Intermittent Treadmill Running in Active Males. Nutrients. 2024.
- New Zealand Rugby. Integrity and supplements guidance.
- World Rugby. Nutrition and Supplements guidance.
- Sport Integrity Commission Te Kahu Raunui. Supplement Decision Making Guide.
