Objectives　CBEX-Dr is a chicken breast extract containing imidazole dipeptides developed by Nippon Meat Packers, Inc. We investigated the effect of CBEX-Dr-containing drink on physical fatigue in healthy volunteers.
　Methods　In a present double-blind, placebo-controlled, crossover trial, 20 healthy volunteers were randomized to oral CBEX-Dr or placebo administration for 29 days. No statistical differences in age, gender or body mass index（BMI）were shown between the two groups. Subjects took CBEX-Dr（imidazole dipeptides 400 mg）or placebo once a day for 29 days. As a fatigue-inducing physical task, subjects performed workload trials on a cycle ergometer at fixed workloads for 4 hours and then rested for 4 hours. We evaluated physical performance by 10-second high power test and subjective sensation of fatigue by visual analogue scale.
　Results　Oral CBEX-Dr administration inhibited the decrease in physical performance and attenuated fatigue sensation by physical load.
　 Conclusions　CBEX-Dr is effective for the attenuation of fatigue and CBEX-Dr-containing drink is one of the promising candidates for anti-fatigue food.