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New Zealand blackcurrant extract can lower exercise-related fatigue factors by 40% during cycling in a competition-ready Ironman athlete, according to a first-ever case study of its kind1.
The blackcurrant extract supplement, CurraNZ®, also lowered the athlete’s heart rate and his level of perceived exertion during four hours of constant-power cycling.
This is the first study to show the acute, adaptive power of the berry extract for influencing factors that underpin performance in highly trained athletes.
Earlier cohort studies have shown that longer intake at lower doses can improve performance up to an impressive 11% after 7-days intake of 300mg-600mg 2-10.
This study was notable for several reasons, being the first dataset to test the effects of an ergogenic aid on an Ironman athlete close to competition.
It was also the first time that researchers have tested one-dose effects of 1200mg of the proprietary CurraNZ 35% blackcurrant anthocyanin extract in a super-fit endurance athlete.
Professor Mark Willems, who led the study at the University of Chichester, says, “this is an exciting step forward in our understanding of blackcurrant.
“We were delighted to be able to test this athlete three weeks before Ironman Barcelona in 2023 – it isn’t often we can access these athletes.
“He already had a high degree of training adaptations required to complete Ironman - so we certainly weren’t expecting to see these outcomes.
“Here, blackcurrant has really moved the needle on key factors related to performance in a race-fit Ironman triathlete. While we didn’t test performance, these outcomes, and the fact that he found the effort less hard with blackcurrant, show the supplement may be beneficial for competition - it is very exciting, unique and novel.
“Interestingly, this individual was a volunteer in earlier blackcurrant performance studies that used lower doses and he wasn’t a clear responder. While things change over time, it suggests that perhaps one dose of four capsules of extract really hits the ‘sweet spot’.”
The placebo-controlled, randomized, cross-over single-blind study showed that 4 capsules (1200mg) of blackcurrant extract, two hours before the testing session:
The 49-year-old athlete, a veteran of 14 Ironman events in 16 years, followed a personalized fuelling strategy of eight energy and carbohydrate gels, bananas and water ad libitum.
Metabolic and heart rate measurements, blood samples and expired air were collected every 60 minutes.
Willems: ‘Reducing heart rate by ten beats a minute is A LOT’
Reflecting on the athlete’s lower perceived exertion and heart rate, Professor Willems says, “lowering the heart rate by ten beats per minute across four hours of constant-power cycling is a lot.
“One likely explanation is the supplement optimised blood flow and when that happens, the body works less hard to circulate blood.
“A lower heart rate is a good sign because in long duration exercise, especially in hot conditions, because you get cardiovascular drift over time, depending on the intensity of the exercise. It’s common to see the heart rate getting higher and higher as the exercise protocol goes on, so a lower starting point means you can go for longer before you reach the point where intensity of exercise is not comfortable anymore.
“The athlete’s experience of the two testing sessions reflected this too – it was very obvious to him when he was using blackcurrant, it was much less difficult than the placebo session.”
Fat oxidation suggested some blunting effects from carbohydrate intake
There was a trend for 13% increase in fat oxidation, which is slightly lower than previous 7-day dosing observations of 17%-25% in men during exercise.
Professor Willems says: “We think this athlete’s fat burning alterations could have been blunted by the carbohydrate gels and bananas every 30 minutes, but we don’t know by how much. Even so, it is still a very good indication that an acute dose still had an effect – we’re confident that if we see a change in fat oxidation, it’s due to intake of blackcurrant.”
CurraNZ has been the subject of over ten years of research and the most effective dosing strategies are still being explored – as well as how highly trained athletes respond to the supplement.
The plant bioactives in blackcurrants, called anthocyanins, increase blood flow, oxygen uptake, reoxygenation rates and use in muscle. Additionally, they are valuable for fuelling strategies, by boosting the body’s reliance on using fat as fuel and reducing carbohydrate – all factors that are implicated in the production of lactate, an indicator of muscle fatigue.
CurraNZ® is a naturally-sourced fitness supplement made from New Zealand blackcurrants.
The science leader in blackcurrant fitness supplements, CurraNZ is supported by 50+ peer-reviewed studies that showcase its exceptional sports performance, muscle recovery and GI-protective properties.
New Zealand’s strong sunlight, high UV levels and cold winters are unique environmental factors that create a berry with one of the highest anthocyanin levels in the world and 1.5 times the concentrations found in European-grown varieties, with powerful antioxidant, anti-inflammatory and blood flow-promoting functions.
The award-winning product is fast becoming a staple supplement of active people, including leading US and British ultra-runners and triathletes.
CurraNZ is certified by Informed-Sport, the global quality assurance program.
30 capsules of CurraNZ Original is available from curranz.com, curranzusa.com and Amazon UK, DE and USA.
