title: A Single Dose of Beetroot Gel Rich in Nitrate Does Not Improve Performance but Lowers Blood Glucose in Physically Active Individuals.
abstract: Background. Beetroot consumption has been proposed to improve exercise performance, since the nitrate content of this food is able to stimulate the synthesis of nitric oxide.Objective. The acute effect of 100 g of a beetroot gel containing ~10 mmol of nitrate was tested on the nitric oxide synthesis, on metabolic and biochemical parameters, and on performance in physically active individuals.Methods. Through a double blind, crossover, placebo-controlled study, 25 healthy runners ingested a single dose of beetroot and placebo gels. Participants performed an aerobic exercise protocol on a treadmill (3 min warm-up of 40% peak oxygen consumption, 4 min at 90% of gas exchange threshold I and 70% (Δ) maximal end speed until volitional fatigue).Results. Urinary levels of nitrite and nitrate increased after 90 min of beetroot gel ingestion. Plasma glucose concentrations lowered after the exercise and the decrease was maintained for 20 min. Systolic and diastolic blood pressures, serum cortisol, and blood lactate were not altered after the beetroot gel ingestion compared to a placebo gel.Conclusion. The single dose of beetroot gel provoked an increase of nitric oxide synthesis although no improvement on the physical performance of athletes during aerobic submaximal exercise was observed.
authors.affiliation: Instituto de Química, Universidade Federal do Rio de Janeiro, 21941-909 Rio de Janeiro, RJ, Brazil.
authors.forename: Julia
authors.initials: J
authors.lastname: Vasconcellos
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho e Escola de Educação Física e Esporte, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, RJ, Brazil.
authors.forename: Diego
authors.initials: D
authors.lastname: Henrique Silvestre
authors.affiliation: Instituto de Química, Universidade Federal do Rio de Janeiro, 21941-909 Rio de Janeiro, RJ, Brazil.
authors.forename: Diego
authors.identifier: 0000-0002-8278-7067
authors.initials: D
authors.lastname: Dos Santos Baião
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho e Escola de Educação Física e Esporte, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, RJ, Brazil; Division of Endocrinology and Metabolism, Rush University Medical Center, Chicago, IL 60612, USA.
authors.forename: João Pedro
authors.initials: JP
authors.lastname: Werneck-de-Castro
authors.affiliation: Instituto de Nutrição, Núcleo Básico de Nutrição e Dietética, Universidade Federal do Rio de Janeiro, 27979-000 Macaé, RJ, Brazil.
authors.forename: Thiago
authors.initials: T
authors.lastname: Silveira Alvares
authors.affiliation: Instituto de Química, Universidade Federal do Rio de Janeiro, 21941-909 Rio de Janeiro, RJ, Brazil.
authors.forename: Vânia M Flosi
authors.identifier: 0000-0001-6093-134X
authors.initials: VM
authors.lastname: Paschoalin