Oxidative stress
Conditions
Interventions
Subjects were randomized to begin procedures with a 140 mL dose of beetroot juice or control drink (www.randomizer.org) two hours before a treadmill test to exhaustion at 80% VO2 max. Heart rate and p
D27.505.519.217 D27.505.696.706.125
Sponsors
Universidade Federal da Paraíba
Universidade Federal da Paraíba
Eligibility
Sex/Gender
Male
Age
18 Years to 55 Years
Inclusion criteria
Inclusion criteria: Runners for at least one year; be performing uninterrupted training for at least three months; train with the aim of participating in long-term running competitions.
Exclusion criteria
Exclusion criteria: Volunteers who had some chronic degenerative disease; smokers; who made continuous use of any medication; did not participate in all experimental procedures; presented gastrointestinal discomfort to beet juice or control drink.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| “Outcome found 1” It was observed that running promoted a 25.6% increase in oxidative stress when the athletes previously ingested the control drink (3.9 ± 0.7 µM to 4.9 ± 0.7 µM) in the pre- to post-exercise moments ( p=0.01), which is an expected behavior for an exercise session, beetroot juice intake prevented the increase in oxidative stress after the run-to-exhaustion test (3.8 ± 0.9 µM for 3 .9 ± 1.0 µM, 2.6% increase from pre- to post-exercise moments (p=0.08). On the other hand, there was no statistically significant change for the antioxidant capacity between the pre- and post-race moments in both procedures.;"Expected outcome 1" Presentation of the expected outcome: To evaluate the effects of beetroot juice supplementation on oxidative stress. Presentation of the method used to verify the expected outcome: Malondialdehyde was evaluated through the reaction of thiobarbituric acid with the decomposition products of hydroperoxides, according to the method described by Ohkawa, Ohishi and Yagi (1979). Meanwhile, the total antioxidant capacity was quantified in plasma via 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity by the method described by Brand-Williams et al. (1995).;"Expected outcome 2" Presentation of the expected outcome: To evaluate the effects of beet juice supplementation on muscle damage. Presentation of the method used to verify the expected outcome: Plasma concentrations of creatine kinase were evaluated using the International Federation of Clinical Chemistry and Laboratory Medicine (UV-IFCC) method and lactate dehydrogenase enzyme through the Pyruvate-Lactate method, both using kits commercial products (Labtest, Minas Gerais, Brazil), in a Labmax 240 premium automated analyzer (Labtest, Minas Gerais, Brazil), according to the manufacturer's instructions. ;" Outcome found 2" It was observed that the running tests caused muscle wasting, seen by an increase in the serum concentration of creatine kinase both in the experimental grou | — |
Secondary
| Measure | Time frame |
|---|---|
| "Secondary Outcome Found 1" It was observed that the concentration of nitrite increased significantly with the supplementation of beet juice, two hours after the ingestion of the juice, with an increase of 58.14%.;"Expected Secondary Outcome 1" Presentation of the expected outcome: Evaluate plasma nitrite concentrations 2 hours after ingestion of 140 ml of beetroot juice. Presentation of the method used to verify the expected outcome: It was evaluated through the Griess reaction that quantifies the nitrite in the sample through the diazotization reaction forming a pink color chromophore. The reagent was prepared using equal parts of 5% phosphoric acid, 1% sulfanilamide in 5% phosphoric acid, 0.1% N-(1-Naphtyl)-ethylenediamine dihydrochloride (NEED) and distilled water. This will be followed by nitrite/nitrate detection with the addition of 500 µL of Griess reagent to 500 µL of plasma. After 10 minutes, the absorbance was measured in a spectrophotometer (Biospectro SP-22, Curitiba, Brazil) at a wavelength of 532nm. Nitrite concentrations were calculated by extrapolation to a standard curve of NaNO2 and the data expressed in micromoles (GREEN et al, 1981). Ten milliliters of blood were collected from the antecubital vein by a properly experienced nurse, before the intake of beetroot juice or control drink, immediately after 2 hours of supplementation, and after the test until exhaustion. The blood was immediately placed in tubes and centrifuged at 3000 rpm for 15 minutes, then refrigerated at -20 °C until analysis. | — |
Countries
Brazil
Contacts
Public ContactAlexandre Silva
Universidade Federal da Paraíba
Outcome results
None listed