Effects Of Beetroot Juice Supplementation Research Articles

High or low volume beetroot juice supplementation might positively affect physical capacity and isokinetic muscle function in power athletes

BACKGROUND: Beetroot juice is an ergogenic aid containing high levels of nitrate and is known to have many physiological benefits. OBJECTIVE: This study aimed to examine the effects of beetroot juice supplementation on the physical capacity and isokinetic muscle function of power athletes. METHODS: Thirteen power athletes were orally administered three different volumes of beetroot juice: placebo (70 ml), low-volume beetroot juice (70 ml), and high-volume beetroot juice (140 ml). The Harvard step test, 20 m sprint, side-step, reaction time, Wingate test, blood lactate analysis, and isokinetic knee and trunk tests were performed to confirm their physical capacity and isokinetic muscle function. Significant differences between the drink groups were determined using repeated-measures ANOVA. RESULTS: There were no significant differences in the Harvard step, side step, whole-body reaction time, anaerobic power, blood lactate concentration, and isokinetic muscular strength in the knee and trunk for all groups. However, the 20 m sprint and isokinetic muscular endurance of the knee extensor were significantly higher with beetroot juice intake. CONCLUSIONS: Our findings suggest that > 70 ml of beetroot juice supplement before performance may be useful as an ergogenic supplement to improve performance-related physical fitness, including speed and muscular endurance, in power athletes.

Effect of Beetroot Juice Supplementation on Muscle Soreness and Performance Recovery after Exercise-Induced Muscle Damage in Female Volleyball Players.

Beetroot juice (BRJ) contains various bioactive compounds suggested to be effective in improving athlete recovery. However, the number of studies evaluating the effects of BRJ on recovery and muscle soreness (MS) indicators in female athletes is limited. Therefore, the present study aimed to determine the effects of BRJ consumption on the performance recovery indicators and MS after exercise-induced muscle damage (EIMD) in female volleyball players. Twelve young female volleyball players were evaluated in this study. We utilized a randomized, cross-over, and double-blind design during two phases with a 30-day interval (wash-out). During each phase, EIMD was performed first, followed by BRJ or placebo (PLA) supplementation for two days (eight servings of 50 mL). Recovery monitoring of performance indicators and MS was performed after EIMD. The results of wall-sit, V sit and reach (VSFT), vertical jump height (VJH), pressure pain threshold (PPT), and thigh swelling (Sw-T) tests were recorded 48 h after EIMD. Also, the Perceived Muscle Soreness was recorded using the visual analog scale (VAS) 12 (MS-12 h), 24 (MS-24 h), and 48 (MS-48 h) hours after EIMD. The data were analyzed using two-way repeated measures of ANOVA at p < 0.05. Compared to PLA, BRJ supplementation improves wall-sit performance after EIMD (p < 0.05), while reducing Sw-T and perceived muscle soreness (p < 0.05). However, no significant difference was observed between PLA and BRJ in VJH and VSFT performance after EIMD (p > 0.05). Our findings indicate that the consumption of BRJ in female volleyball players can be useful for improving some recovery indicators, such as muscle endurance, perceived muscle soreness, and tissue edema, after EIMD.

Effects of beetroot juice supplementation on vascular functional and structural changes in aged mice.

This study investigated whether beetroot juice (BRJ) ingestion ameliorates aging-induced functional and structural changes in vasculature. Aged mice (98-100 weeks old) were supplemented with BRJ (nitrate: 3.5 mmol/L) or drinking water for 4 weeks and compared with young mice (12-15 weeks old). The vasorelaxant response of isolated aortas to acetylcholine was markedly weaker in aged mice than in young mice, but the attenuated relaxation was significantly improved in BRJ-supplemented aged mice. The acetylcholine-induced relaxation was completely abolished by Nω -nitro-l-arginine methyl ester in all groups. Additionally, the response to sodium nitroprusside was comparable among the three groups. The aortic medial thickness was significantly greater in aged mice than in young mice, and BRJ supplementation did not suppress this thickening. Plasma nitrate levels were significantly higher in BRJ-supplemented aged mice than in non-supplemented aged mice. Conversely, non-supplemented aged mice had high plasma levels of thiobarbituric acid-reactive substances, but the levels were suppressed in BRJ-supplemented aged mice. These findings suggest that BRJ ingestion improves vascular endothelial dysfunction associated with aging, at least in part, by enhancing nitric oxide bioavailability and reducing oxidative stress. Therefore, beetroot ingestion may be a highly useful self-medication option to prevent vascular aging.

Effects of Beetroot Juice Supplementation on Performance, Blood-biochemistry of Kadaknath Chicken Raised Under Farm Conditions

Effects of Beetroot Juice Supplementation on Performance, Blood-biochemistry of Kadaknath Chicken Raised Under Farm Conditions

Ameliorative Effects of Beetroot Juice Supplementation on Monocrotaline-Induced Pulmonary Hypertension in Rats

Beetroot is a nitrate-rich vegetable with cardiovascular benefits. This study examined whether ingestion of beetroot juice (BRJ) protects against pulmonary hypertension (PH). Rats were injected subcutaneously with 60 mg/kg monocrotaline (MCT) and randomized to receive either drinking water, low-dose BRJ (BRJ-L, nitrate content: 1.4 mmol/L), or high-dose BRJ (BRJ-H, nitrate content: 3.5 mmol/L), which was started 1 week after MCT injection and continued until the end of the experiment. Four weeks after MCT injection, right ventricle (RV) hypertrophy, right ventricular systolic pressure (RVSP) elevation, and pulmonary vascular remodeling were observed. These PH symptoms were less severe in rats supplemented with BRJ-L (Fulton index, p = 0.07; RVSP, p = 0.09, pulmonary arterial medial thickening, p &lt; 0.05), and the beneficial effects were more pronounced than those of BRJ-H supplementation. Plasma and RV nitrite and nitrate levels did not change significantly, even when BRJ-L and BRJ-H were administered. There were no differences in plasma thiobarbituric acid reactive substances (TBARS), a biomarker of oxidative stress, among the groups. BRJ-L supplementation significantly decreased RV TBARS levels compared to MCT alone (p &lt; 0.05), whereas BRJ-H supplementation did not. These findings suggest that starting BRJ supplementation from an early stage of PH ameliorates disease severity, at least partly through the inhibition of local oxidative stress. Habitual ingestion of BRJ may be useful for the management of PH.

Dietary Nitrate Does Not Improve Neuromuscular Performance And Match-play Demands In Elite Female Hockey Players.

PURPOSE: Beetroot juice is a commonly used ergogenic aid that contains high levels of inorganic nitrate (NO3-) and that its intake has proven effectivity at increasing blood nitric oxide (NO) concentrations. The ingestion of beetroot juice has shown good evidence of benefits in endurance sports while team sports has been barely studied. In our knowledge, only a few studies have been developed in team sports athletes. The present study was designed to compare the acute effects of beetroot juice supplementation on physical performance and match-play demands in elite female field hockey players METHODS: Eleven well-trained female hockey players (22.78 ± 5.12 years) participated during the preparatory period of their hockey season in this study. Participants were randomly divided into two groups undergoing a neuromuscular test battery with ingestion of 70 mL beetroot juice (6.4 mmol NO3-) or 70 mL placebo (0.04 mmol NO3-) in two separated days with one week between protocols. A neuromuscular test battery consisted in different test such as; countermovement jump (CMJ), isometric handgrip strength (IHS), and repeated sprint ability test (RSA) were realized. Afterwards a simulated hockey match play (2 x 20 minutes) was realized and the data was recorded by Global Positioning System (GPS). RESULTS: No significant improvements were observed in any physical parameters analysed comparing beetroot juice versus placebo ingestion, CMJ (p = 0.776), IHS (p = 0.829), RSA (p = 0.466). Therefore, no differences were reported in any physical match demands measured by GPS (i.e., total distance covered, number of accelerations/decelerations, etc) (p = 0.063-0.941) CONCLUSIONS: Beetroot juice acute supplementation did not produce any statistically significant improvement in physical performance or match-play demands in elite female field hockey players

Potential effect of beetroot juice supplementation on exercise economy in well-trained females.

This study examined if acute dietary nitrate supplementation (140 mL beetroot juice, BRJ) would reduce oxygen consumption (V̇O2) during cycling at power outputs of 50 and 70% maximal oxygen consumption in 14 well-trained female Canadian University Ringette League athletes. BRJ had no effect on V̇O2 or heart rate but significantly reduced ratings of perceived exertion (RPE) at both intensities. Individually, 4 participants responded to BRJ supplementation with a ≥3% reduction in V̇O2 at the higher power output. Novelty: Acute BRJ supplementation did not improve exercise economy in well-trained females, but significantly reduced RPE. However, 4/14 subjects did respond with a ≥3% V̇O2 reduction.

Effects of Beetroot Juice Supplementation on Cognitive Function, Aerobic and Anaerobic Performances of Trained Male Taekwondo Athletes: A Pilot Study.

Studies have shown that nitrate (NO3−)-rich beetroot juice (BJ) supplementation improves endurance and high-intensity intermittent exercise. The dose–response effects on taekwondo following BJ supplementation are yet to be determined. This study aimed to investigate two acute doses of 400 mg of NO3− (BJ-400) and 800 mg of NO3− (BJ-800) on taekwondo-specific performance and cognitive function tests compared with a placebo (PL) and control (CON) conditions. Eight trained male taekwondo athletes (age: 20 ± 4 years, height: 180 ± 2 cm, body mass: 64.8 ± 4.0 kg) completed four experimental trials using a randomized, double-blind placebo-controlled design: BJ-400, BJ-800, PL, and CON. Participants consumed two doses of BJ-400 and BJ-800 or nitrate-depleted PL at 2.5 h prior to performing the Multiple Frequency Speed of Kick Test (FSKT). Countermovement jump (CMJ) was performed before the (FSKT) and PSTT, whereas cognitive function was assessed (via the Stroop test) before and after supplementation and 10 min following PSTT. Blood lactate was collected before the CMJ tests immediately and 3 min after the FSKT and PSST; rating of perceived exertion (RPE) was recorded during and after both specific taekwondo tests. No significant differences (p > 0.05), with moderate and large effect sizes, between conditions were observed for PSTT and FSKT performances. In addition, blood lactate, RPE, heart rate, and CMJ height were not significantly different among conditions (p > 0.05). However, after the PSTT test, cognitive function was higher in BJ-400 compared to other treatments (p < 0.05). It was concluded that acute intake of 400 and 800 mg of NO3− rich BJ reported a moderate to large effect size in anaerobic and aerobic; however, no statistical differences were found in taekwondo-specific performance.

The Effect Of Beetroot Juice Supplementation On Muscle Fatigue In Healthy Adults; A Meta-analysis

Dietary supplementation with beetroot juice has been reported its positive effects on diverse aspects of sports performance, but its effect on muscle fatigue remains unclear. PURPOSE: The purpose of this meta-analysis is to investigate the effect of beetroot juice supplement on muscle fatigue assessed by changes in strength or power outputs. METHODS: The meta-analysis followed Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Through the comprehensive search using major databases including Science Direct, PubMed (MEDLINE), SPORTDiscus, Web of Science, and Academic Search Complete, 215 relevant studies were identified. Three search terms used to identify a potentially relevant article; “Beetroot” AND “Exercise” AND “Fatigue”. The inclusion criteria for the search included: 1) human subjects, 2) exercise type (Strength and Power), 3) the peer-reviewed journals published in English. Out of 215, data from the 30 trials were extracted for inclusion in the meta-analysis. Comprehensive meta-analysis v.3 software was used to compute the standardized mean difference effect sizes based on a random effects model. Several moderator analyses were conducted to examine the effect of dosage, timing of supplementation, type of measure, gender and participation on the overall effect size. The Egger’s test was used to evaluate for no evidence of publication bias. RESULTS: The results showed a significant positive effect of beetroot juice supplementation on muscle fatigue: the overall strength of ESs (Hedges’ g) was .313 (95% CI = .128, .499, p = .001; moderate effects; cf., Cohen’s criteria). This data was indicated reducing fatigue from pre and post-test. The prediction interval was -.453 to 1.08, indicating that there are some populations where the impact of beetroot juice on fatigue would be negative. There was no significant effect of moderators (dosage, timing of supplementation, acute vs. chronic), measuring type (strength and power), gender, and participation (athletes vs. non-athletes) on the size of the effect. CONCLUSION: This study shows that dietary supplementation with beetroot juice significantly reduces fatigue indicated by reducing strength and power outputs.

The Effects of Beetroot Juice Supplementation on Balance Performance of Wrestlers

Aim: This study assessed the effect of beetroot juice supplementation on the dynamic and static balance performance of wrestlers at rest and fatigue conditions. Material and methods: The study was conducted with 3 trial days. The study is a double blind, randomized, cro ssover design in which eight trained male Greco Roman wrestlers (age 21.87±2.3 years; height 176.87± 4.1 cm; body weight 76.75± 5. 4 kg) consumed beetroot juice (BRJ) (140 ml) or placebo (PLA) (140 ml, cherry juice with lemon juice) 150 min before performin g balance performance test. Subjects were administered standard warm up and then dynamic and static balance tests were performed to the dominant leg with by Biodex Balance System (BBS, Biodex Medical Systems Inc., Shirley, NY) at rest. Following balance te sting, each subject got into a fatigue strength exercise (FSE) to create fatigue for the dominant leg. Immediately after the ( FSE), subjects were applied to dynamic and static balance test to the dominant leg again at fatigue. The same trial procedure was repeated with the other supplement (BRJ or P LA ) in the third testing trial five days later. Paired sample T test was used for comparison of BRJ and P LA balance performance values. Result: Although there were no significant changes in static OSI, APSI balance scores, Static MLSI improved significantly in favor of BRJ in rest . Dynamic OSI and APSI paramet er s improved significantly but not MLSI in the BRJ trial. While all static and dynamic b alance parameters improved statistically, only static MLSI w as not changed by the BRJ trial at fatigue. Conclusion: Consuming BRJ can be useful to maintain balance performance and prevent sports injuries in training or competition. Keywords: Beetroot Juice, Dietary Nitrate, Balance, Wrestlers.

The effect of beetroot juice supplementation on muscle performance during isokinetic knee extensions in male Taekwondo athletes

Summary Objectives Little information is available regarding the effects of beetroot juice (BRJ) on muscle performance and contractions during resistance exercise. The muscle strength and power of the lower extremity is an important attribute in Taekwondo, therefore, present study examines the effects of 6 days of BRJ supplementations on muscle performance during isokinetic contractions of knee muscle in male Taekwondo athletes. Equipments and methods Twelve male Taekwondo athletes (age, 19.2 ± 1.6 yrs) were volunteered to take part in this double-blind, placebo-controlled, randomized crossover design. Participants consumed either 140 mL nitrate-rich concentrated BRJ (∼12.8 mmol NO3−) or placebo (blackcurrant juice) for six consecutive days. On the last day of supplementation, the knee extensions were performed on a Biodex isokinetic dynamometer. Treatment periods were separated by a 10-day washout periods. Results Knee extensor peak torque increased significantly (P

An Untargeted Metabolomics Approach to Investigate the Metabolic Effect of Beetroot Juice Supplementation in Fencers-A Preliminary Study.

This study aimed at assessment of the long-term (4 weeks) metabolic effect of a diet with and without beetroot juice supplementation in fencers using the untargeted metabolomics method with the UPLC Q-TOF/MS system to carry out an analysis of urine samples. Ten women and 10 men underwent the cardiovascular fitness VO2max test at baseline—(B) and after two stages of implementation of the dietary recommendations—the first 4 weeks without beetroot juice (D) and the second with 26 g/d of freeze-dried beetroot juice supplementation (D&J). The urine samples were collected one hour after the VO2max test at B and after D and D&J. The meal before the VO2max test after D&J contained beetroot juice, whereas to the meal at B and after D maltodextrin was added. Changes in metabolites and VO2max were significant only for comparison of D versus D&J. During D and D&J, there were no significant changes in the physical activity level, body mass, and body composition. We observed significant changes in tyrosine and tryptophan metabolism, mainly associated with such neurotransmitter’s metabolism as: Serotonin, noradrenaline, and adrenaline. Changes in signal intensity of bile acid, AICAR, and 4-Hydroxynonenal (peroxidation of polyunsaturated fatty acids product) were also observed. The obtained results indicate that long-term beetroot juice supplementation induces considerable changes in metabolism.

Effect of Beetroot Juice Supplementation on Mood, Perceived Exertion, and Performance During a 30-Second Wingate Test.

Dietary supplementation with inorganic nitrate (NO3-) can enhance high-intensity exercise performance by improving skeletal muscle contractility and metabolism, but the extent to which this might be linked to altered psychophysiological processes is presently unclear. The purpose of this study was to assess the effects of NO3--rich beetroot juice (BJ) supplementation on profile of mood states, ratings of perceived exertion (RPE), and performance in a 30-second Wingate cycle test. In a double-blind, randomized, cross-over study, 15 subjects completed 2 laboratory sessions after ingesting NO3--rich or NO3--depleted (placebo) BJ. Participants initially completed the profile of mood states questionnaire. Subsequently, participants completed a warm-up followed by a 30-second all-out Wingate cycling test. After the Wingate test, participants immediately indicated the RPE of their leg muscles (RPEmuscular), cardiovascular system (RPEcardio), and general RPE (RPEgeneral). Compared with the placebo condition, supplementation with BJ increased peak power output (Wpeak) (+4.4%, 11.5 [0.7] vs 11.1 [1.0] W·kg-1; P = .039) and lowered the time taken to reach Wpeak (7.3 [0.9] vs 8.7 [1.5]s; P = .002) during the Wingate test. The profile of mood states score linked to tension was increased prior to the Wingate test (4.8 [3.0] vs 3.4 [2.4]; P = .040), and RPEmuscular was lowered immediately following the Wingate test (17.7 [1.6] vs 18.3 [1.0]; P = .031), after BJ compared with placebo ingestion. Acute BJ supplementation improved pre-exercise tension, 30-second Wingate test performance, and lowered postexercise RPEmuscular.

No Effect of Beetroot Juice Supplementation on 100-m and 200-m Swimming Performance in Moderately Trained Swimmers.

Purpose: Dietary nitrate supplementation has been reported to improve performance in kayaking and rowing exercise, which mandate significant recruitment of the upper-body musculature. Because the effect of dietary nitrate supplementation on swimming performance is unclear, the purpose of this study was to assess the effect of dietary nitrate supplementation on 100-m and 200-m swimming freestyle time-trial (TT) performance. Methods: In a double-blind, randomized crossover design, 10 moderately trained swimmers underwent 2 separate 3-d supplementation periods, with a daily dose of either 140mL nitrate-rich (∼800mg/d nitrate) or nitrate-depleted (PLA) beetroot juice (BRJ). After blood sampling on day 3, the swimmers performed both 200-m and 100-m freestyle swimming TTs, with 30 min recovery between trials. Results: Plasma nitrite concentration was greater after BRJ relative to PLA consumption (432 [203]nmol/L, 111 [56]nmol/L, respectively, P = .001). Systolic blood pressure was lowered after BRJ compared with PLA supplementation (114 [10], 120 [10]mmHg, respectively P = .001), but time to complete the 200-m (BRJ 152.6 [14.1]s, PLA 152.5 [14.1]s) and 100-m (BRJ 69.5 [7.2]s, PLA 69.4 [7.4]s) freestyle swimming TTs was not different between BRJ and PLA (P > .05). Conclusions: Although 3 d of BRJ supplementation increased plasma nitrite concentration and lowered blood pressure, it did not improve 100-m and 200-m swimming TT performance. These results do not support an ergogenic effect of nitrate supplementation in moderately trained swimmers, at least for 100-m and 200-m freestyle swimming performance.

Effect of Beetroot Juice Supplementation on Thermoregulation and Running in a Hot Environment

Effect of Beetroot Juice Supplementation on Thermoregulation and Running in a Hot Environment

No effect of beetroot juice supplementation on exercise economy and performance in recreationally active females despite increased torque production.

This study investigated the effects of acute and chronic beetroot juice (BRJ) supplementation on submaximal exercise oxygen uptake (VO 2), time trial (TT) performance, and contractile properties of the plantar flexors in females. Study 1: Using a double blind, randomized, crossover design, 12 recreationally active females using hormonal contraceptives supplemented acutely (2.5 h) and chronically (8 days) with 280 mL BRJ/d (~26 mmoles nitrate [NO3−]) or a NO3−‐free placebo (PLA). On days 1 and 8, participants cycled for 10 min at 50% and 70% VO 2peak and completed a 4 kJ/kg body mass TT. Plasma [NO3−] and nitrite ([NO2 −]) increased significantly following BRJ supplementation versus PLA. There was no effect of BRJ supplementation on VO 2 at 50% or 70% VO 2peak, or TT performance. Study 2: 12 recreationally active females (n = 7 from Study 1) using hormonal contraceptives participated in a baseline visit and were supplemented acutely (2.5 h) and chronically (8 days) with 280 mL BRJ/d. Maximum voluntary strength (MVC) of the plantar flexors was assessed and a torque‐frequency curve performed. BRJ had no effect on MVC, voluntary activation, peak twitch torque, time to peak torque, or half relaxation time. Following both acute (46.6 ± 4.9% of 100 Hz torque) and chronic (47.2 ± 4.4%) supplementation, 10 Hz torque was significantly greater compared to baseline (32.9 ± 2.6%). In summary, BRJ may not be an effective ergogenic aid in recreationally active females as it did not reduce submaximal exercise VO 2 or improve aerobic TT performance despite increasing low frequency torque production.

The effect of beetroot juice supplementation on repeat-sprint performance in hypoxia

ABSTRACTThis investigation assessed the effect of dietary nitrate (NO3−) supplementation, in the form of beetroot juice (BR), on repeat-sprint performance in normoxia and normobaric hypoxia. 12 male team-sport athletes (age 22.3 ± 2.6 y, VO2peak 53.1 ± 8.7 mL.kg−1.min−1) completed three exercise trials involving a 10 min submaximal warm-up and 4 sets of cycling repeat-sprint efforts (RSE; 9 × 4 s) at sea level (CON), or at 3000 m simulated altitude following acute supplementation (140 mL) with BR (HYPBR; 13 mmol NO3−) or NO3–depleted BR placebo (HYPPLA). Peak (PPO) and mean (MPO) power output, plus work decrement were recorded during the RSE task, while oxygen consumption (VO2) was measured during the warm-up. There were no significant differences observed between HYPBR and HYPPLA for PPO or MPO; however, work decrement was reduced in the first RSE set in HYPBR compared with HYPPLA. There was a moderate effect for VO2 to be lower following BR at the end of the 10 min warm-up (ES = 0.50 ± 0.51). Dietary NO3− may not improve repeat-sprint performance in hypoxia but may reduce VO2 during submaximal exercise. Therefore, BR supplementation may be more effective for performance improvement during predominantly aerobic exercise.

The effects of beetroot juice supplementation on exercise economy, rating of perceived exertion and running mechanics in elite distance runners: A double-blinded, randomized study.

PurposeNitrate-rich beetroot juice supplementation has been extensively used to increase exercise economy in different populations. However, its use in elite distance runners, and its potential effects on biomechanical aspects of running have not been properly investigated. This study aims to analyze the potential effects of 15 days of beetroot juice supplementation on physiological, psychological and biomechanical variables in elite runners.MethodsTwelve elite middle and long-distance runners (age = 26.3 ± 5.1yrs, VO2Max = 71.8±5.2 ml*kg-1*min-1) completed an incremental running test to exhaustion on a treadmill before and after a 15-days supplementation period, in which half of the group (EG) consumed a daily nitrate-rich beetroot juice and the other group (PG) consumed a placebo drink. Time to exhaustion (TEx), running economy, vastus lateralis oxygen saturation (SmO2), leg stiffness and rate of perceived exertion (RPE) were measured at 15, 17.1 and 20 km/h during the incremental test.ResultsLikely to very likely improvements in EG were observed for the RPE (Standardized mean difference (SMD) = -2.17, 90%CI = -3.23, -1.1), SmO2 (SMD = 0.72, 90%CI = 0.03, 1.41) and TEx (SMD = 1.18, 90%CI = -0.14, 2.5) in comparison with PG. No other physiological or biomechanical variable showed substantial improvements after the supplementation period.ConclusionsFifteen days of nitrate-rich beetroot juice supplementation produced substantial improvements in the time to exhaustion in elite runners; however, it didn’t produce meaningful improvements in running economy, VO2Max or mechanical parameters.

Effect of beetroot juice supplementation on 10-km performance in recreational runners.

The purpose of this study was to investigate the effects of chronic beetroot juice (BRJ) supplementation on 10-km running performance in recreational runners. In a double-blind, placebo-controlled, crossover-designed study, 14 male recreational runners (age, 27.8 ± 3.4 years) performed three 10-km running tests, at baseline and under the conditions of BRJ supplementation and placebo (PLA). Supplementation was administered for 3 days, and on the days of the assessments, the ingestion occurred 2 h before the test and consisted of a dose of 420 mL of BRJ in natura (8.4 mmol inorganic nitrate (NO3-)·day-1) or PLA with depleted NO3- (0.01 mmol NO3-·day-1). The mean velocity (MV) was calculated, and the following variables were determined: maximal heart rate, maximal rating of perceived exertion, blood glucose concentration (analyzed before and after the test), and lactate peak. There was no main effect between conditions regarding 10-km running time performance (BRJ: 50.1 ± 5.3 min; PLA: 51.0 ± 5.1 min; P = 0.391) and total MV (BRJ: 12.1 ± 1.3 km·h-1; PLA: 11.9 ± 1.2 km·h-1; P = 0.321) or in the other analyzed variables. The time to complete the first half of the test (5 km) was statistically lower in the BRJ group than in the PLA group (P = 0.027). In conclusion, chronic supplementation with BRJ increased MV in the first half of the test and improved the final test times of 10 of the 14 runners, although we did not find a statistically significant difference in the performance of the 10-km run.

The Effect of Beetroot Juice Supplementation on Physiological Fatigue and Quality of Sleep in Male Athletes

The Effect of Beetroot Juice Supplementation on Physiological Fatigue and Quality of Sleep in Male Athletes