Recent research has shown that dietary nitrate has favorable effects on blood flow and exercise performance. The purpose of this randomized, double-blind, placebo-controlled crossover study was to investigate the acute effects of pomegranate extract on blood flow, vessel diameter, and exercise performance in active individuals. Nineteen men and women (mean ± SD: age, 22.2 ± 2.2 years; height, 174.8 ± 10.7 cm; body mass, 71.9 ± 13.5 kg) were randomly assigned to a placebo (PL) or pomegranate extract (PE) group. Participants performed a maximal oxygen consumption treadmill test to determine peak velocity (PV). Participants returned after 24-48 h and ingested either PL or PE. Brachial artery blood flow was assessed using ultrasound at baseline and 30 min post-ingestion (30minPI). Three treadmill runs to exhaustion were performed at 90%, 100%, and 110% PV. Blood flow was assessed immediately after each exercise bout and 30 min postexercise (30minPEx). After a 7-10 day washout, participants repeated the same procedures, ingesting the opposite supplement. Separate repeated measures ANOVAs were performed for blood flow, vessel diameter, and time to exhaustion (TTE). Blood flow was significantly augmented (p = 0.033) 30minPI with PE in comparison with PL. Vessel diameter was significantly larger (p = 0.036) 30minPEx with PE. Ingestion of PE was found to significantly augment TTE at 90% (p = 0.009) and 100% PV (p = 0.027). Acute ingestion of PE 30 min before exercise may enhance vessel diameter and blood flow and delay fatigue during exercise. Results of the current study indicate that PE is ergogenic for intermittent running, eliciting beneficial effects on blood flow.
Keywords: diamètre vasculaire; efficacité mitochondriale; exercise hyperemia; exercise tolerance; flow-mediated dilation; hyperhémie d’effort; mitochondrial efficiency; nitrate; nitric oxide; nitrite; oxyde nitrique; polyphenol; polyphénol; tolérance à l’effort; vasodilatation; vasodilatation dépendante du flux sanguin; vasodilation; vessel diameter.