Effects of acute beetroot juice intake on performance, maximal oxygen uptake, and ventilatory efficiency in well-trained master rowers: a randomized, double-blinded crossover study.

BACKGROUND: Beetroot juice (BRJ) intake has been considered a practical nutritional strategy among well-trained athletes. This study aimed to assess the effects of BRJ intake on performance, cardiorespiratory and metabolic variables during a simulated 2000-meter rowing ergometer test in well-trained master rowers. METHOD: Ten well-trained male master rowers (30-48 years) participated in a randomized, double-blind, crossover design for 3 weeks. In the first week, a researcher explained all the experimental procedures to the participants. In the next two weeks, the participants were tested in 2 rowing ergometer sessions, separated from each other by a 7-day washout period. In both strictly identical sessions, the participants randomly drank BRJ or placebo (PL) 3 hours before the start of the tests. Subsequently, the participants carried out the 2000-meter rowing ergometer tests. Oxygen saturation and blood lactate measurements were performed before starting (pretest) and at the end of the test (posttest). Performance parameters and cardiorespiratory variables were recorded during the rowing ergometer test. RESULTS: An improvement in time trial performance was observed, with a mean difference of 4 seconds (90% confidence limits ± 3.10; p ≤ 0.05) compared to PL. Relative and absolute maximaloxygenuptakeV˙O2max increased (mean difference of 2.10 mL·kg-1·min-1, 90% confidence limits ± 1.80; mean difference of 0.16 L·min-1 90% confidence limits ± 0.11, respectively; p ≤ 0.05) compared to PL. No ergogenic effect was observed on ventilatory efficiency and blood lactate concentrations after BRJ intake. CONCLUSION: Acute BRJ intake may improve time trial performance as well as V˙O2max in well-trained master rowers. However, BRJ does not appear to improve ventilatory efficiency.

Acute Effects of Caffeine Intake on Psychological Responses and High-Intensity Exercise Performance.

OBJECTIVE: The aim of this study was to investigate the effects of caffeine supplementation on: (i) psychological responses of subjective vitality and mood; (ii) performance through a Wingate test; and (iii) rate of perceived exertion (RPE) reported after a Wingate test. METHODS: Fifteen male participants (22.60 ± 2.16 years) ingested 6 mg·kg-1 of caffeine or placebo (sucrose) supplementation in two experimental sessions. After 60 min from supplement intake, participants fulfilled two questionnaires, which measured subjective vitality and mood state, respectively. Subsequently, participants' performance was assessed through a Wingate test, which was followed by measurements of RPE at general, muscular, or cardiovascular level. RESULTS: Caffeine supplementation increased some components of mood, as assessed by profile of mood states (POMS) (tension and vigor dimensions) and subjective vitality profiles, which were followed by a greater maximum power, average power, and lower time needed to reach maximum power during the Wingate test. Moreover, lower RPE, both at muscular and general levels were reported by participants after the Wingate test. CONCLUSIONS: These results suggest that caffeine supplementation exerts positive effects both in psychological and physical domains in trained subjects.

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

PURPOSE: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: Acute BJ supplementation improved pre-exercise tension, 30-second Wingate test performance, and lowered postexercise RPEmuscular.

Caffeine Supplementation Improves Anaerobic Performance and Neuromuscular Efficiency and Fatigue in Olympic-Level Boxers.

BACKGROUND: this study examined the effects of caffeine supplementation on anaerobic performance, neuromuscular efficiency and upper and lower extremities fatigue in Olympic-level boxers. METHODS: Eight male athletes, members of the Spanish National Olympic Team, were enrolled in the study. In a randomized double-blind, placebo-controlled, counterbalanced, crossover design, the athletes completed 2 test sessions after the intake of caffeine (6 mg·kg-1) or placebo. Sessions involved initial measures of lactate, handgrip and countermovement jump (CMJ) performance, followed by a 30-seconds Wingate test, and then final measures of the previous variables. During the sessions, electromiography (EMG) data were recorded on the gluteus maximus, biceps femoris, vastus lateralis, gastrocnemius lateral head and tibialis anterior. RESULTS: caffeine enhanced peak power (6.27%, p < 0.01; Effect Size (ES) = 1.26), mean power (5.21%; p < 0.01; ES = 1.29) and reduced the time needed to reach peak power (-9.91%, p < 0.01; ES = 0.58) in the Wingate test, improved jump height in the CMJ (+2.4 cm, p < 0.01), and improved neuromuscular efficiency at peak power in the vastus lateralis (ES = 1.01) and gluteus maximus (ES = 0.89), and mean power in the vastus lateralis (ES = 0.95) and tibialis anterior (ES = 0.83). CONCLUSIONS: in these Olympic-level boxers, caffeine supplementation improved anaerobic performance without affecting EMG activity and fatigue levels in the lower limbs. Further benefits observed were enhanced neuromuscular efficiency in some muscles and improved reaction speed.

Effects of a single dose of beetroot juice on cycling time trial performance at ventilatory thresholds intensity in male triathletes.

BACKGROUND: Beetroot juice (BJ) is classified as a high-level supplement for improving sports performance. There is some controversy over the benefits of BJ supplementation for endurance exercise performance, especially when referring to well-trained athletes. This study examines the effects of acute BJ supplementation on cardioventilatory responses, exercise economy/efficiency, slow component of oxygen uptake, time trial performance, blood lactate, energy consumption, and carbohydrate and fat oxidation. METHODS: Twelve well-trained, male triathletes (aged 21-47 yr) were assigned in a randomized, double-blind, crossover design to receive 70 ml of BJ (6.5 mmol NO3-) or placebo (PL). Three hours after taking the supplement, participants completed an endurance test on a cycle ergometer at a constant work rate (W) corresponding to first ventilatory threshold (VT1) (30 min) and second ventilatory threshold (VT2) time trial (~ 15 min). RESULTS: Maximal oxygen uptake was 54.78 ± 3.13 mL·min- 1·kg- 1, and gross efficiency was > 22% at each load intensity and experimental condition. No significant interaction effect (supplement*intensity) was observed on any of the cardioventilatory variables, efficiency/economy, VT2 time trial, energy expenditure, carbohydrate oxidation and fat oxidation (p > 0.05). CONCLUSION: Our findings do not support an improvement in the variables examined in response to acute BJ supplementation. Probably, higher doses are needed for improving time trial performance in male triathletes during a cycle ergometer test conducted at a load intensity equivalent to the first and second ventilatory threshold.

Effects of Beetroot Juice Supplementation on Performance and Fatigue in a 30-s All-Out Sprint Exercise: A Randomized, Double-Blind Cross-Over Study.

As a nitric oxide precursor, beetroot juice (BJ) is known to enhance high-intensity exercise performance (80⁻100% VO2max) yet its impacts on higher intensity sprint exercise (>100% VO2max) remain to be established. This study sought to examine the effects of BJ supplementation on performance and subsequent fatigue during an all-out sprint exercise. Using a randomized cross-over, double-blind, placebo-controlled design, 15 healthy resistance-trained men (22.4 ± 1.6 years) ingested 70 mL of either BJ or placebo. Three hours later, participants undertook a 30-s all-out Wingate test. Before and after the sprint exercise and at 30 s and 180 s post-exercise, three countermovement jumps (CMJ) were performed and blood lactate samples were obtained. Compared to placebo, BJ consumption improved peak (placebo vs. BJ, 848 ± 134 vs. 881 ± 135 W; p = 0.049) and mean (641 ± 91 vs. 666 ± 100 W; p = 0.023) power output and also reduced the time taken to reach Wpeak in the Wingate test (8.9 ± 1.4 vs. 7.3 ± 0.9 s; p = 0.003). No differences were detected in the fatigue index. In addition, while over time CMJ height and power diminished (ANOVA p < 0.001) and blood lactate levels increased (ANOVA p < 0.001), no supplementation effect was observed. Our findings indicate that while BJ supplementation improved performance at the 30-s cycling sprint, this improvement was not accompanied by differences in fatigue during or after this type of exercise.

Effects of beetroot juice supplementation on intermittent high-intensity exercise efforts.

Beetroot juice contains high levels of inorganic nitrate (NO3-) and its intake has proved effective at increasing blood nitric oxide (NO) concentrations. Given the effects of NO in promoting vasodilation and blood flow with beneficial impacts on muscle contraction, several studies have detected an ergogenic effect of beetroot juice supplementation on exercise efforts with high oxidative energy metabolism demands. However, only a scarce yet growing number of investigations have sought to assess the effects of this supplement on performance at high-intensity exercise. Here we review the few studies that have addressed this issue. The databases Dialnet, Elsevier, Medline, Pubmed and Web of Science were searched for articles in English, Portuguese and Spanish published from 2010 to March 31 to 2017 using the keywords: beet or beetroot or nitrate or nitrite and supplement or supplementation or nutrition or "sport nutrition" and exercise or sport or "physical activity" or effort or athlete. Nine articles fulfilling the inclusion criteria were identified. Results indicate that beetroot juice given as a single dose or over a few days may improve performance at intermittent, high-intensity efforts with short rest periods. The improvements observed were attributed to faster phosphocreatine resynthesis which could delay its depletion during repetitive exercise efforts. In addition, beetroot juice supplementation could improve muscle power output via a mechanism involving a faster muscle shortening velocity. The findings of some studies also suggested improved indicators of muscular fatigue, though the mechanism involved in this effect remains unclear.

Effects of ß-alanine supplementation during a 5-week strength training program: a randomized, controlled study.

BACKGROUND: ß-Alanine (BA) is a non-essential amino acid that has been shown to enhance exercise performance. The purpose of this investigation was to determine if BA supplementation improved the adaptive response to five weeks of a resistance training program. METHODS: Thirty healthy, strength-trained individuals were randomly assigned to the experimental groups placebo (PLA) or BA. Over 5 weeks of strength training, subjects in BA took 6.4 g/day of BA as 8 × 800 mg doses each at least 1.5 h apart. The training program consisted of 3 sessions per week in which three different leg exercises were conducted as a circuit (back squat, barbell step ups and loaded jumping lunges). The program started with 3 sets of 40 s of work per exercise and rest periods between sets of 120 s in the first week. This training volume was then gradually built up to 5 sets of 20 s work/60 s rest in the fifth week. The work load during the program was set by one of the authors according to the individual's perceived effort the previous week. The variables measured were average velocity, peak velocity, average power, peak power, and load in kg in a back squat, incremental load, one-repetition maximum (1RM) test. In addition, during the rest period, jump ability (jump height and power) was assessed on a force platform. To compare data, a general linear model with repeated measures two-way analysis of variance was used. RESULTS: Significantly greater training improvements were observed in the BA group versus PLA group (p = 0.045) in the variables average power at 1RM (BA: 42.65%, 95% CI, 432.33, 522.52 VS. PLA: 21.07%, 95% CI, 384.77, 482.19) and average power at maximum power output (p = 0.037) (BA: 20.17%, 95% CI, 637.82, 751.90 VS. PLA; 10.74%, 95% CI, 628.31, 751.53). The pre- to post training average power gain produced at 1RM in BA could be explained by a greater maximal strength gain, or load lifted at 1RM (p = 0.014) (24 kg, 95% CI, 19.45, 28.41 VS. 16 kg, 95% CI, 10.58, 20.25) and in the number of sets executed (p = 0.025) in the incremental load test (BA: 2.79 sets, 95% CI, 2.08, 3.49 VS. PLA: 1.58 sets, 95% CI, 0.82, 2.34). CONCLUSIONS: ß-Alanine supplementation was effective at increasing power output when lifting loads equivalent to the individual's maximal strength or when working at maximum power output. The improvement observed at 1RM was explained by a greater load lifted, or strength gain, in response to training in the participants who took this supplement.

Effects of Beetroot Juice Supplementation on a 30-s High-Intensity Inertial Cycle Ergometer Test.

Background: Beetroot juice (BJ) is rich in inorganic nitrates and has proved effective at increasing blood nitric oxide (NO) levels. When used as a supplement BJ has shown an ergogenic effect on cardiorespiratory resistance exercise modalities, yet few studies have examined its impact on high intensity efforts. Objective: To assess the effects of BJ intake on anaerobic performance in a Wingate test. Methods: Fifteen trained men (age 21.46 ± 1.72 years, height 1.78 ± 0.07 cm and weight 76.90 ± 8.67 kg) undertook a 30-s maximum intensity test on an inertial cycle ergometer after drinking 70 mL of BJ (5.6 mmol NO3-) or placebo. Results: Despite no impacts of BJ on the mean power recorded during the test, improvements were produced in peak power (6%) (p = 0.034), average power 0-15 s (6.7%) (p = 0.048) and final blood lactate levels (82.6%) (p < 0.001), and there was a trend towards a shorter time taken to attain peak power (-8.4%) (p = 0.055). Conclusions: Supplementation with BJ has an ergonomic effect on maximum power output and on average power during the first 15 s of a 30-s maximum intensity inertial cycle ergometer test.

University students' food consumption assessment and the relation with their academic profile / Evaluación del consumo de alimentos de una población de estudiantes universitarios y su relación con el perfil académico

Objective: The purpose of this research is to assess the quality of the diet taken by the students of Universidad Alfonso X El Sabio (Madrid) and to learn whether having a specific knowledge about nutrition produce positive effects in food behavior. Methods: 390 students were tested, 72.63% of them studied degrees in relation to health sciences whereas the remaining 27.37% did not. The students were between 18 and 25 years old. The information was gathered through a questionnaire. This information dealt with frequency of food consumption as well as weight and height in order to get the body mass index. Results: The breakdown of the population according to their body mass index was the following: 75.54% normal weight, 11.06% low weight, 13.4% obesity. These figures are considered normal and they are similar to other groups of students. Both groups (health science students and the others) showed a lower cereal, vegetable and fruit consumption in comparison with the recommended percentage; whereas the consumption of pulses was higher than the average in Spain and the average from other groups, almost reaching the recommendable minimum. In addition, both groups showed a high consumption of dairies. No striking differences have been found between both groups. When comparing both of them in relation to gender, women showed better food behavior since they ate more fruit, vegetables and white fish. Conclusion: No differences have been found between the group studying health sciences and the students studying other kind of degree. The obtained results show that the food consumption of the population is far from the stipulated recommendations; therefore, it would be necessary to design a new action plan regarding nutrition.

Objetivo: el propósito de este estudio ha sido evaluar la calidad de la alimentación de los estudiantes de la Universidad Alfonso X El Sabio (Madrid) y establecer si tener una formación específica sobre temas de nutrición produce efectos positivos en los comportamientos alimentarios. Métodos: la muestra estuvo formada por 390 estudiantes, 72,63% de Ciencias de la Salud (CS) y 27,37% de otras carreras (No CS), con edades comprendidas entre 18 y 25 años. A través de un cuestionario se recabó información sobre frecuencia de consumo de alimentos. También se obtuvieron datos sobre el peso y la talla para calcular el índice de masa corporal (IMC). Resultados: la distribución de la población según el IMC fue la siguiente: 75,54% normopeso, 11,06% bajo peso, 13,4% obesidad; valores dentro de la normalidad y similares a los de otros grupos de estudiantes. Los dos grupos presentaron un consumo inferior al recomendado de cereales, verduras, hortalizas y fruta; a su vez, el consumo de legumbres fue superior a la media española y a la de otros jóvenes, llegando casi al mínimo recomendado. También se dio, en ambos grupos, un elevado consumo de lácteos. No se ha encontrado diferencias significativas entre titulaciones. Al comparar los datos para la variable sexo, el grupo de mujeres presentó un patrón de consumo más adecuado, con una mayor ingesta de fruta, verdura y pescado blanco. Conclusión: no se han visto diferencias en el comportamiento alimentario entre los dos grupos analizados (CS y No CS). Los resultados obtenidos indican que el consumo de alimentos de esta población se aleja de las recomendaciones establecidas, por lo que convendría diseñar un plan de actuación en materia nutricional.

Evaluación del consumo de alimentos de una población de estudiantes universitarios y su relación con el perfil académico / University students’ food consumption assessment and the relation with their academic profile

Objetivo: el propósito de este estudio ha sido evaluar la calidad de la alimentación de los estudiantes de la Universidad Alfonso X El Sabio (Madrid) y establecer si tener una formación específica sobre temas de nutrición produce efectos positivos en los comportamientos alimentarios. Métodos: la muestra estuvo formada por 390 estudiantes, 72,63% de Ciencias de la Salud (CS) y 27,37% de otras carreras (No CS), con edades comprendidas entre 18 y 25 años. A través de un cuestionario se recabó información sobre frecuencia de consumo de alimentos. También se obtuvieron datos sobre el peso y la talla para calcular el índice de masa corporal (IMC). Resultados: la distribución de la población según el IMC fue la siguiente: 75,54% normopeso, 11,06% bajo peso, 13,4% obesidad; valores dentro de la normalidad y similares a los de otros grupos de estudiantes. Los dos grupos presentaron un consumo inferior al recomendado de cereales, verduras, hortalizas y fruta; a su vez, el consumo de legumbres fue superior a la media española y a la de otros jóvenes, llegando casi al mínimo recomendado. También se dio, en ambos grupos, un elevado consumo de lácteos. No se ha encontrado diferencias significativas entre titulaciones. Al comparar los datos para la variable sexo, el grupo de mujeres presentó un patrón de consumo más adecuado, con una mayor ingesta de fruta, verdura y pescado blanco. Conclusión: no se han visto diferencias en el comportamiento alimentario entre los dos grupos analizados (CS y No CS). Los resultados obtenidos indican que el consumo de alimentos de esta población se aleja de las recomendaciones establecidas, por lo que convendría diseñar un plan de actuación en materia nutricional (AU)

Objective: The purpose of this research is to assess the quality of the diet taken by the students of Universidad Alfonso X El Sabio (Madrid) and to learn whether having a specific knowledge about nutrition produce positive effects in food behavior. Methods: 390 students were tested, 72.63% of them studied degrees in relation to health sciences whereas the remaining 27.37% did not. The students were between 18 and 25 years old. The information was gathered through a questionnaire. This information dealt with frequency of food consumption as well as weight and height in order to get the body mass index. Results: The breakdown of the population according to their body mass index was the following: 75.54% normal weight, 11.06% low weight, 13.4% obesity. These figures are considered normal and they are similar to other groups of students. Both groups (health science students and the others) showed a lower cereal, vegetable and fruit consumption in comparison with the recommended percentage; whereas the consumption of pulses was higher than the average in Spain and the average from other groups, almost reaching the recommendable minimum. In addition, both groups showed a high consumption of dairies. No striking differences have been found between both groups. When comparing both of them in relation to gender, women showed better food behavior since they ate more fruit, vegetables and white fish. Conclusion: No differences have been found between the group studying health sciences and the students studying other kind of degree. The obtained results show that the food consumption of the population is far from the stipulated recommendations; therefore, it would be necessary to design a new action plan regarding nutrition (AU)