EXERCISE in the heat places one of the most severe demands on the gastro-intestinal system and which affects 90% of endurance athletes. Johnny Brownlee's near-collapse in the World Series in Mexico 2016 is such an example.
However, scientists have discovered 'robust evidence' that the anti-inflammatory and blood flow-promoting effects of blackcurrant anthocyanins in CurraNZ offer multiple potent benefits for those exercising in hot conditions.
Scientists from the University of Chichester tested the effects of seven days' intake of two capsules of blackcurrant extract on athletes during exercise in a heat and chamber discovered it reduced the risk of gastro-intestinal stress during exercise and boosted fat oxidation by a whopping 30%.
Exercise in the heat causes oxidative stress and a redistribution in blood flow away from the gut, leading to a host of symptoms that, if left uncontrolled, can impair exercise performance and may even lead to more severe outcomes such as heat illness.
Early data has found ‘robust evidence’ that blackcurrant anthocyanins, which have anti-inflammatory properties and reduce oxidative stress, help to reduce gastro-intestinal damage.
This is in contrast to beetroot, which raises the body's core temperature in the heat, and should not be used.
The stunning new blackcurrant findings are particularly relevant to ultra-marathon runners who compete at lower exercise intensities, and to endurance athletes who train in hot conditions.
What the scientists are saying about the studies
Dr Ben Lee, the researcher leading the heat stress study, says: “The caveat with this is that we didn’t prime participants with carbohydrate gels or drinks, which is what athletes typically use during training and competition, and can make them ill. However, we did see a reduction in upper and lower GI symptoms in athletes using blackcurrant, plus a reduction in other related symptoms, such as nausea, stitch and dizziness.
“There will be a full data set in 12 months, however at this stage of the analysis, it seems that blackcurrant helps maintain intestinal integrity. If you were due to compete in the heat, you could consider the use of blackcurrant in the week tapering before the event if you suffer from GI distress.”
Blackcurrant's effect on fat burning can lead to less fatigue in the heat
COMPARED to normal temperatures, the body burns less fat and more carbohydrate when exercising in the heat. This new research suggests that blackcurrant counteracts the decline that occurs to fat burning under hot conditions.
The University of Chichester's Professor Mark Willems says: “Athletes participating in really long events like IronMan don’t have fat-loading strategies, they have carbohydrate-loading strategies before and during the race. The consequence of using more carbohydrate is that its by-products lead to greater fatigue than if you were burning fat. So, it’s a good thing if you can rely less on carbohydrate.
“What we are seeing here is blackcurrant causes a really substantial increase to fat oxidation in the heat. It may help restore fat burning closer to rates associated with exercise in normal conditions.
“We weren’t expecting to find anything, so we have no idea why blackcurrant is providing such a stimulus in these conditions.
“An increase of 30% is a very high value for a supplement, even in a fasted state. For some reason, the combination of polyphenols and heat is having a big effect. We don’t know the reason but it’s a very exciting finding.
“Our next step is to conduct a performance study in the heat to see if blackcurrant does have a performance effect under hot conditions.”
The experienced researcher, who has authored 12 peer-review published papers on blackcurrant for sports performance, says: “We’re building a very nice picture that New Zealand blackcurrant is potent in many aspects. This latest heat study is taking us into new territory with blackcurrant and with all the data we have so far, it’s proving potent in itself, compared to other anthocyanin-rich products.
“We are realising that it maybe the specific blackcurrant anthocyanin composition that is making this berry stand out from the others.”