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Effects of Blackcurrant Extract During High-Intensity Intermittent Running: An Exploratory Study of Possible Muscle
Mark E T Willems1, Sam D Blacker1, Ian C Perkins1
1School of Sport, Science and Engineering, University of Chichester, Chichester PO19 6PE, UK.
Muscles (Basel, Switzerland)
|November 24, 2025
Summary
Anthocyanin-rich blackcurrant extract may enhance high-intensity intermittent running performance, but benefits appear specific to individuals with a predominant slow-twitch (Type I) muscle fiber typology. Further research is needed to confirm these findings and understand individual responses to ergogenic aids.
Area of Science:
- Exercise Physiology
- Nutritional Biochemistry
- Sports Science
Background:
- Anthocyanin-rich blackcurrant extract has demonstrated muscle fiber-type specific force responses during fatigue.
- Previous research indicated potential ergogenic effects, but the influence of muscle fiber type was not fully elucidated.
Purpose of the Study:
- To investigate the muscle fiber-type specific effects of blackcurrant extract on high-intensity intermittent treadmill running performance.
- To explore whether the ergogenic potential of blackcurrant extract is influenced by individual muscle fiber typology.
Main Methods:
- An exploratory, randomized, double-blind, crossover study involving 16 active males.
- Participants underwent a 7-day supplementation of blackcurrant extract (210 mg anthocyanins/day) or placebo, followed by high-intensity intermittent running to exhaustion.
- Muscle fiber typology was predicted using voluntary maximal isometric contractions.
Main Results:
- No significant correlation was found between isometric force decline and running performance across all participants.
- Individuals with a predominant slow-twitch (Type I) muscle fiber typology showed significant improvements in total running distance (17%) and high-intensity running distance (15%).
- No differences in heart rate or lactate levels at exhaustion were observed between muscle fiber type groups.
Conclusions:
- The ergogenic effect of anthocyanin-rich blackcurrant extract on high-intensity intermittent exercise may be dependent on an individual's muscle fiber type.
- Predominant slow-twitch muscle fibers appear to benefit more from blackcurrant extract supplementation during this type of exercise.
- Larger, robust studies are required to confirm these exploratory findings and elucidate inter-individual responses to nutritional ergogenic aids.
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