Dietary quercetin supplementation is not ergogenic in untrained men.
Quercetin supplementation increases muscle oxidative capacity and endurance in mice, but its ergogenic effect in humans has not been established. Our study investigates the effects of short-duration chronic quercetin supplementation on muscle oxidative capacity; metabolic, perceptual, and neuromuscular determinants of performance in prolonged exercise; and cycling performance in untrained men. Using a double-blind, pretest-posttest control group design, 30 recreationally active, but not endurance-trained, young men were randomly assigned to quercetin and placebo groups. A noninvasive measure of muscle oxidative capacity (phosphocreatine recovery rate using magnetic resonance spectroscopy), peak oxygen uptake (Vo(2peak)), metabolic and perceptual responses to submaximal exercise, work performed on a 10-min maximal-effort cycling test following the submaximal cycling, and voluntary and electrically evoked strength loss following cycling were measured before and after 7-16 days of supplementation with 1 g/day of quercetin in a sports hydration beverage or a placebo beverage. Pretreatment-to-posttreatment changes in phosphocreatine recovery time constant, Vo(2peak,) substrate utilization, and perception of effort during submaximal exercise, total work done during the 10-min maximal effort cycling trial, and voluntary and electrically evoked strength loss were not significantly different (P > 0.05) in the quercetin and placebo groups. Short duration, chronic dietary quercetin supplementation in untrained men does not improve muscle oxidative capacity; metabolic, neuromuscular and perceptual determinants of performance in prolonged exercise; or cycling performance. The null findings indicate that metabolic and physical performance consequences of quercetin supplementation observed in mice should not be generalized to humans.
Cureton
Kirk J
KJ
Department of Kinesiology, Ramsey Center, 330 River Road, Univ. of Georgia Athens, GA 30602-6554. kcureton@uga.edu
Tomporowski
Phillip D
PD
Singhal
Arpit
A
Pasley
Jeffrey D
JD
Bigelman
Kevin A
KA
Lambourne
Kathleen
K
Trilk
Jennifer L
JL
McCully
Kevin K
KK
Arnaud
Maurice J
MJ
Zhao
Qun
Q
D020155:3-Hydroxybutyric Acid / Q000097:blood; D000284:Administration, Oral; D000328:Adult; D001628:Beverages; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000187:drug effects; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D004558:Electric Stimulation; D004734:Energy Metabolism / Q000187:drug effects*; D015444:Exercise; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005990:Glycerol / Q000097:blood; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D053580:Muscle Strength / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D010725:Phosphocreatine / Q000097:blood; D011794:Quercetin / Q000008:administration & dosage* / Q000097:blood; D013997:Time Factors; D055815:Young Adult
D015415:Biomarkers; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D010725:Phosphocreatine; D011794:Quercetin; D005990:Glycerol; D020155:3-Hydroxybutyric Acid