Writing in the journal Nutrition , lead author Suzuka Ataka from Osaka City University Graduate School of Medicine reports that oral supplementation with the apple extract may find a place in the growing sports nutrition market.
A market report published by Mintel in September 2005 valued the UK sports nutrition market at £207 m (€301.9 m) - growth of 122.6 per cent since 2001.
The market is currently dominated by drinks.
"We found that oral administration of Applephenon (1200 mg/d) for 1 wk improved physical performance during fatigue-inducing workload trials on a bicycle ergometer," wrote Ataka.
"This is the first report demonstrating that Applephenon improves physical fatigue."
In a double-blinded, placebo-controlled, three-way crossover trial, the researchers recruited 18 healthy volunteers (average age 39, nine women, average BMI 25.1 kg per sq. m) and randomised to oral supplementation with Applephenon (Asahi Breweries), ascorbic acid (1000 mg/d, Iwaki Seiyaku Co.), or placebo for eight days.
Participants undertook fatigue-inducing physical exercise using a bicycle ergometer for two hours on two occasions.
Ataka and co-workers report that the change in maximum velocity (top speed that the participants could reach and maintain for ten seconds) between the 30- and 210-minute trials was higher in the Applephenon-supplemented group than the placebo group, while vitamin C was found to have no effect.
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The active component of Applephenon is procyanidin, which has been shown to have no toxicity," said the researchers.
"Muscular exercise promotes the production of radicals and other reactive oxygen species, which are responsible for exercise-induced protein oxidation and contribute to physical fatigue.
Therefore, the administration of Applephenon may attenuate physical fatigue through its activity as an antioxidant," they said.
"To evaluate the effects of Applephenon on long-term fatigue, studies involving a long-term fatigue-inducing period must be performed," concluded Ataka.
Source: Nutrition (Elsevier) May 2007, Volume 23, Issue 5, Pages 419-423 "Effects of Applephenon and ascorbic acid on physical fatigue" Authors: S. Ataka, M. Tanaka, S. Nozaki, H. Mizuma, K. Mizuno, T. Tahara, T. Sugino, T. Shirai, Y. Kajimoto, H. Kuratsune