Background: Physical exercise has been reported to increase the bioavailability of citrus flavanones.
Objective: We investigated the bioavailability of orange juice (OJ) (poly) phenols in endurance-trained males before and after cessation of training for 7 d.
Design: Ten fit, endurance-trained males, with a mean +/- SD maximal oxygen consumption of 58.2 +/- 5.3 mL.kg(-1) min 21, followed a low (poly) phenol diet for 2 d before drinking 500 mL of OJ containing 398 mu mol of (poly) phenols, of which 330 mu mol was flavanones. After the volunteers stopped training for 7 d the feeding study was repeated. Urine samples were collected 12 h pre-and 24 h post-OJ consumption. Bioavailability was assessed by the quantitative analysis of urinary flavanone metabolites and (poly) phenol catabolites with the use of high-pressure liquid chromatography-high resolution mass spectrometry.
Results: During training, 0-24-h urinary excretion of flavanone metabolites, mainly hesperetin-3'-O-glucuronide, hesperetin-3'-sulfate, naringenin-4'-O-glucuronide, naringenin-7-O-glucuronide, was equivalent to 4.2% of OJ flavanone intake. This increased significantly to 5.2% when OJ was consumed after the volunteers stopped training for 7 d. Overall, this trend, although not significant, was also observed with OJ-derived colonic catabolites, which, after supplementation in the trained state, were excreted in amounts equivalent to 51% of intake compared with 59% after cessation of training. However, ...