Study shows CurraNZ can benefit any athlete - and performance effect is influenced by muscle fibre type

Study shows CurraNZ can benefit any athlete - and performance effect is influenced by muscle fibre type

RESEARCHERS from the University of Chichester have discovered that the muscle fibre type of athletes is a key factor in how New Zealand blackcurrant extract can positively influence the performance of athletes.

In the study, Effect of New Zealand Blackcurrant Extract on Isometric Contraction-Induced Fatigue and Recovery: Potential Muscle-Fiber Specific Effects, Professor Mark Willems and his team discovered individuals respond in different ways to the New Zealand blackcurrant supplement, CurraNZ®, depending on their muscle fibre type.

The outcomes highlight how New Zealand blackcurrant extract can enhance the efficiency of fast-twitch muscle fibre contractions, leading to greater force production in exercise. In simple terms, the blackcurrant supplement allows the muscle to work like a well-oiled machine, producing a greater amount of force.



Those with slow twitch fibres - or 'endurance' athletes - demonstrated a substantial increase in their resistance to fatigue. These findings suggest blackcurrant could potentially provide major benefits within endurance-based activities. In less scientific terms, this effectively means the supplementation of blackcurrant allows individuals to work harder for longer

The study, published in the Journal Sport in October, reveals the effect of seven days' intake of 600mg CurraNZ® New Zealand blackcurrant extract on individuals with fast and slow-twitch fibre types during a fatiguing exercise protocol.

In the double-blind, randomized, crossover design study, individuals were identified by their predominant muscle fibre type. They performed a series of fatiguing isometric contractions of the quadriceps, during which their maximal muscle contraction force was measured.

The study found:

  • Individuals with Type 1 (Slow Twitch, ie ‘endurance’) fibres had an increased resistance to fatigue with a 10% increase in force production in the final stage.
  • Individuals with Type 2 (Fast Twitch, ie ‘sprint’) fibres produced 14% greater force during the initial stages of the fatiguing exercise protocol.
  • 92% of Type 2 participants produced higher force production early in the protocol

 The study was a follow-up to a program of cycling and running studies that have shown that New Zealand blackcurrant improves athletic performance in recreational and elite athletes in ranges up to an average of 11%.


'It doesn't matter what muscle fibre type you are to receive a benefit from blackcurrant'


Professor Willems (left), who is leading the program of blackcurrant sports performance research at the University, says: “This study has shown that if you are an individual who likes high-intensity, repeated exercise, you would benefit from blackcurrant and if you are individual who likes endurance exercise, you would also benefit from an ability to be more resistant to fatigue.

“It doesn’t matter whether you are a Type 1 or Type 2 individual, you will receive beneficial effects from using blackcurrant.

"Those with Type 2 muscle fibre types are, most of the time, individuals who do high-intensity repeated sprint exercises such as rugby, basketball & football players. In this case, when they perform repeated contractions, they may have an ability to produce more force during those contractions where the blackcurrant supplement has been taken.

“We’ve already seen in previous performance studies that blackcurrant supplementation provides increased fatigue resistance and increased endurance effect leading to improved endurance performance. This study confirms this effect in Type 1 individuals, based on what we have observed in some of the whole-body exercise studies.

“However, the interpretation of the findings is challenging in a sense, as an isolated muscle group was tested, therefore it is necessary to be careful with the generalization of the results to whole body movements, further research in this area will allow for a greater understanding of the benefits CurraNZ has on different muscle fibres.

“Nevertheless, it is exciting to see such findings.”