Article

Ingestion of a Nitric Oxide Enhancing Supplement Improves Resistance Exercise Performance

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Abstract

Studies have established that supplementation of nitrate increases nitrous oxide which in turn improves exercise performance. The current study aimed to investigate the effects of nitrate ingestion on performance of bench press resistance exercise till failure. Twelve recreationally active (age, 21 ± 2yrs, height, 177.2 ± 4.0 cm, weight, 82.49 ± 9.78 kg) resistance trained males participated in the study. The study utilised a double blind randomized cross-over design, where participants ingested either 70 ml of "BEET It Sport ®" nitrate shot containing 6.4 millimoles (mmol/L) or 400 mg of nitrate; or a blackcurrant placebo drink. Participants completed a resistance exercise session, consisting of bench press exercise at an intensity of 60% of their established 1 repetition maximum (1-RM), for three sets until failure with 2 minute rest interval between sets. The repetitions completed, total weight lifted, local and general rate of perceived exertion (RPE), and blood lactate were all measured. The results showed a significant difference in repetitions to failure (p < 0.001) and total weight lifted (p < 0.001). However there were no significant difference between blood lactate over the two trials (p = 0.238), and no difference in Local (p = 0.807) or general (p = 0.420) indicators of fatigue as measured by RPE. This study demonstrates that nitrate supplementation has the potential to improve resistance training performance and work output compared to a placebo.

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... During high-intensity exercise, fatigue is typically understood to be caused by insufficient energy supply to the working tissue in connection with the accumulation of intramuscular metabolic by-products (Ca 2+ , H + , and Pi) (14). Under aerobic and anaerobic conditions, the ability to offset these issues through increased blood flow has been shown to improve performance (10,15,22). Systemic nitric oxide (NO) levels play an integral role in regulating blood flow and mitochondrial respiration through vasodilation of the smooth muscles in the arterioles and improved oxygen uptake kinetics in favor of aerobic bioenergetics, thus mitigating the onset of fatigue caused by anaerobic metabolism (25). ...
... Previous studies (3,11) that have looked at beetroot nitrates and the effect on oxygen cost found that long duration, lower intensity exercise benefitted from supplementation by reducing oxygen cost by ~3-6% (6). Similarly, when HIIT exercise modalities were examined, beetroot supplementation showed positive improvements in power and sprint time (4,15,16,25). These intermittent exercise modalities, however, incorporated some designated rest periods between efforts, whereas this study had no designated rest periods. ...
... The HIFT workout consisted of five 400m runs followed by weighted overhead squats. While the workout took around 15 minutes to complete, demonstrating potential aerobic properties, the high level of lactate and HR response indicated a much higher anaerobic demand than the HIIT studies (4,15,16,25). Mosher et al (15) reported post-exercise lactate levels of 4.0 ± 0.7 mmol· L -1 following resistance training repetitions to failure at 60% 1RM, whereas the HIFT workout reported post-exercise lactate levels of 10.71 ± 2.35 mmol· L -1 . Additionally, the vascular constriction elicited during the overhead squats may have counteracted the vasodilation effects of the nitrate supplementation reduction to NO (21). ...
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International Journal of Exercise Science 13(2): 667-676, 2020. Nitrate supplementation (NO3-) has been shown to improve athletic performance for short-duration, vigorous activity, as well as long-duration, aerobic activity. The purpose was to explore the effects of beetroot supplementation (BR) on high-intensity functional training (HIFT) performance. Twenty-four HIFT participants (25 ± 6.5 years, 175.17 ± 8.1 cm, 84.94 ± 12.09 kg), who attended HIFT classes at least 3 days per week for the past 3 months, performed a benchmark performance test (5 rounds of a 400-m run followed by 15 overhead squats with a 95-lb (for males)/65-lb (for females) barbell). In a randomized order, 72 hrs apart, participants were tested under a control session and once after consuming 70 mL beetroot nitrate supplement, Beet It Ⓡ , 2 hours prior to beginning the assigned benchmark test. For both benchmark tests, time to completion, pre-and post-exercise blood lactate levels, RPE, and pre-, during, and post-exercising heart rates were measured. There was no significant difference (p < 0.05) between the control (930 ± 192.6 sec) and supplement (952.8 ± 205.8 sec) on time to complete the performance test. Post-exercise blood lactate (11.14 ± 2.84 mm/dL) was not significantly different (p < 0.05) than the control (12.00 ± 2.53 mm/dL). Additionally, mean RPE for BR supplement (14.78 ± 2.50) was not significantly different (p < 0.05) than the control (14.92 ± 2.12). The short duration and high intensity of the workout, which included both anaerobic and aerobic components, may have mitigated the cardiovascular effect of beetroot nitrates unlike previous research that found significant positive effects between beetroot nitrates and exercise performance.
... A small number of studies have been published of late regarding resistance exercise and nitric oxide precursors. Initial work by Mosher et al. [21] revealed that a short loading phase (6 days) increased total volume lifted during bench press resistance exercise at 60% of 1 repetition maximum (1RM). Williams and colleagues [22] subsequently showed that acute BRJ supplementation increased mean velocity and mean power output across 3 sets of bench press to repetitions failure. ...
... Our findings that RSE supplementation did not have a significant effect on resistance exercise performance are not in-line with recent studies regarding dietary NO 3 − consumption and bench press performance [21]. Mosher and colleagues [21] reported that repetitions to failure and total weight lifted across 3 sets of the bench press at 60% 1RM was significantly greater following 6 days of NO 3 − supplementation (400 mg) compared to a placebo treatment. ...
... Our findings that RSE supplementation did not have a significant effect on resistance exercise performance are not in-line with recent studies regarding dietary NO 3 − consumption and bench press performance [21]. Mosher and colleagues [21] reported that repetitions to failure and total weight lifted across 3 sets of the bench press at 60% 1RM was significantly greater following 6 days of NO 3 − supplementation (400 mg) compared to a placebo treatment. Additionally, another study implemented a single dose of NO 3 − (400 mg) 2 h prior to exercise and reported that acute BRJ supplementation significantly increased the total number of bench press repetitions completed across 3 sets to failure [22]. ...
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The purpose of this study was to assess the impact of short-term dietary nitrate supplementation, in the form of red spinach extract (RSE), on bench press performance, muscle oxygenation, and cognitive function in resistance-trained males. Ten resistance-trained males participated in this randomized, cross-over, placebo-controlled, double-blind investigation. Each participant completed 7 days of either RSE (2 g; 180 mg NO3−) or a maltodextrin placebo (PL) in a counterbalanced fashion with a 14-day washout between treatments. During experimental visits, participants were provided their 8th and last dose of RSE or PL 40 min before completing 5 sets of the barbell bench press exercise to failure at 75% of a predetermined 1-repetition maximum with 2 min rest intervals. Mean and peak power were recorded via a linear transducer. Near-infrared spectroscopy (NIRS) was implemented to estimate muscle oxygenation, a Stroop Test was used to assess cognitive function, and subjective performance ratings were obtained in relation to the acute resistance exercise sessions. Data were analyzed via separate repeated measures analyses of variance. There were no time by group interactions for bench press repetitions (p = 0.549), peak power (p = 0.061), or mean power (p = 0.877) across the 5 sets of bench press. Additionally, no significant differences (p > 0.05) were observed for any measure of muscle oxygenation, Stroop performance, or subjective performance ratings. It appears that 7 days of RSE supplementation did not alter performance, muscle oxygenation, nor Stroop scores during or following the bench press exercise in resistance-trained males.
... Bailey et al. (2) reported that 6 days of BRJ supplementation improved knee extension tests and reduced phosphocreatine (ATP-PC) cost during exercise. Further supporting this, Mosher et al. (24) showed that 6 days of BRJ ingestion increased total volume during Smith-machine bench press exercise at 60% of 1 repetition maximum (1RM). Mechanisms underlying these changes in resistance exercise performance may be due to enhanced neuromuscular efficiency (11), reduced ATP-PC cost (2), and changes in calcium handling (14). ...
... Previous investigations have shown that acute BRJ improves isometric force production and multiday supplementation increases number of repetitions completed during Smith-machine bench press (4,24). However, no studies to date have examined the effects of acute BRJ supplementation on power output, velocity, and total volume during free-weight resistance exercise. ...
... Our results of increased total repetitions during free-weight bench press agree with these findings albeit at a higher load. Unlike our findings, Mosher et al. (24) reported that over 3 sets of RTF, BRJ supplementation resulted in higher repetitions performed over all 3 sets vs. this study which only saw total repetition improvements. Differences in results may be due to exercise equipment and supplementation period. ...
Article
Williams, TD, Martin, MP, Mintz, JA, Rogers, RR, and Ballmann, CG. Effect of acute beetroot juice supplementation on bench press power, velocity, and repetition volume. J Strength Cond Res XX(X): 000-000, 2019-The purpose of this study was to examine the effects of acute beetroot juice (BRJ) supplementation on power, velocity, and repetitions to failure (RTF) during bench press exercise. Resistance-trained male subjects (n = 11) were recruited for this study. Using a double-blinded, counterbalanced, crossover study design, subjects were supplemented with either 70 ml of BRJ or placebo (PL; black currant juice) 2 hours before exercise. During each exercise trial, subjects began by completing 2 sets × 2 repetitions of bench press at 70% 1 repetition maximum (1RM) with maximum explosive intent. Barbell velocity and power were measured using a linear position transducer. Subjects then completed 3 sets × RTF at 70% 1RM separated by 2 minutes of rest between each set. Maximum mean power, velocity, and repetitions were analyzed. Mean velocity (p = 0.011; effect size [ES] = 0.54) and mean power (p = 0.015; ES = 0.51) were significantly higher with BRJ when compared with PL. Total RTF (p = 0.002; ES = 0.46) was higher during the BRJ condition vs. PL. Results indicate that acute BRJ supplementation positively impacts velocity, power, and total repetitions during free-weight bench press exercise.
... However, BJ supplements in resistance training (RT) [13][14][15] have received less attention [16]. Mosher et al. [14] supplemented 12 active men for six days with BJ and placebo (PLA), observing an increase in muscular endurance in terms of weightlifting and number of repetitions. ...
... However, BJ supplements in resistance training (RT) [13][14][15] have received less attention [16]. Mosher et al. [14] supplemented 12 active men for six days with BJ and placebo (PLA), observing an increase in muscular endurance in terms of weightlifting and number of repetitions. Similarly, Bailey et al. [13] recruited seven active men who consumed BJ for six days, reporting an improvement of strength, reducing the total use of ATP and increasing the concentration of NO3 in the plasma. ...
... The participants lifted 20 kg on a Smith machine as quickly and explosively as possible for a total of three repetitions and were given form correction if necessary. Before starting the protocol, to know the 1-RM, a warm-up based on previous studies that studied the effects of BJ on RT [14,15] was carried out, checking that the participants could bear it well. Testing protocol to find 1-RM load in back squat and bench press followed the suggestions proposed by Brown and Weir [24]. ...
Article
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The ingestion of beetroot juice (BJ) has been associated with improvements in physical performance in endurance sports, however the literature on resistance training (RT) is scarce. The aim of this study was to investigate the acute effects of BJ compared to a placebo (PLA) on muscular endurance and movement concentric velocity during RT. Twelve healthy men performed an incremental RT test (back squat and bench press) with three sets, at 60%, 70%, and 80% of their repetition maximum (1-RM). Movement velocity variables, total number of repetitions performed until concentric failure, blood lactate, and ratings of perceived effort post-training were measured. A higher number of repetitions were recorded with BJ compared to those with PLA (13.8 ± 14.4; p < 0.01; effect size (ES) = 0.6). Differences were found at 60% 1-RM (9 ± 10; p < 0.05; ES = 0.61) and 70% 1-RM (3.1 ± 4.8; p < 0.05; ES = 0.49), however, no differences were found at 80% 1-RM (1.7 ± 1; p = 0.12; ES = 0.41). A greater number of repetitions was performed in back squat (13.4 ± 13; p < 0.01; ES = 0.77), but no differences were observed in bench press (0.4 ± 5.1; p = 0.785; ES = 0.03). No differences were found for the rest of the variables (p > 0.05). Acute supplementation of BJ improved muscular endurance performance in RT.
... Nitric oxide (NO) precursor supplements, such as arginine, citrulline, and beetroot juice (BEET), are a popular class of dietary supplements that are typically marketed toward physically active populations as ergogenic aids 2010). A number of recent studies have documented performance improvements following NO precursor supplementation in a variety of exercise tasks, such as cycling (Bailey et al. 2009;Cermak et al. 2012), running , rowing (Bond et al. 2012), and resistance exercise (Perez-Guisado and Jakeman 2010; Wax et al. 2015;Mosher et al. 2016;Wax et al. 2016). Nitric oxide is purported to elicit several physiological responses that may influence resistance exercise performance, with evidence suggesting that NO induces favorable changes in blood flow, exercise efficiency, and muscle fatigue (Bailey et al. 2012). ...
... While most studies evaluating nitrate-induced improvements in energy efficiency have been carried out using aerobic exercise modalities, only one has used a leg extension task similar to resistance exercise . While an enhancement of energy efficiency was observed after four to six days of supplementation, more research is required to replicate this finding to determine whether energy efficiency enhancement may contribute to previously reported improvements in resistance exercise performance following six days of BEET supplementation (Mosher et al. 2016). For citrulline-based supplements, effects on energy efficiency during exercise are unclear. ...
... During a cycling time trial, seven days of L-citrulline was not found to significantly affect VO 2 response in comparison to a placebo treatment, but the ratio of power output to oxygen consumption tended to be higher in the citrulline condition (Suzuki et al. 2016). While both BEET (Mosher et al. 2016) and citrulline malate (CitMal) (Perez-Guisado and Jakeman 2010; Wax et al. 2015; have been found to delay fatigue during exhaustive resistance exercise, these supplements provide different NO precursors, which target different NO production pathways that are stimulated and inhibited by distinct physiological conditions (Bailey et al. 2012). More research is needed to determine whether these ingredients induce similar effects on energy efficiency, particularly with respect to resistance exercise. ...
Article
The ergogenic effects of citrulline malate (CitMal) and beetroot juice (BEET) have been widely studied, but their effects on physiological outcomes related to resistance exercise are not fully understood. The purpose of this randomized, double-blind, crossover study was to investigate the effects of CitMal (8 g) and BEET (400 mg nitrate) on blood pressure (BP), blood flow, and energy efficiency during submaximal leg extension. Recreationally active males (n = 27; age: 22 ± 4 yrs) completed familiarization, followed by three testing visits. Supine and standing BP were measured upon arrival, followed by supplement ingestion, a 2-h rest period, postsupplement BP measurement, and a bout of repeated submaximal isotonic leg extensions at 25% of maximal voluntary contraction torque. Diameter (aDIAM) and blood flow (aBF) of the superficial femoral artery, and cross-sectional area (CSA) and echo intensity (EI) of the vastus lateralis, were measured before and after exercise via ultrasonography. Muscle blood flow (mBF) and oxygen consumption (mVO2), along with whole-body energy expenditure (EE) and respiratory exchange ratio (RER), were measured before and during exercise via indirect calorimetry and near-infrared spectroscopy. Baseline RER values differed among treatments (p = 0.01); BEET was higher than CitMal (p = 0.01) but not PLA (p = 0.58); CitMal and PLA were not significantly different (p = 0.12). No other measurements were significantly affected by treatment (all p > 0.05). Results suggest that neither CitMal nor BEET significantly influence resting BP, blood flow, or metabolic efficiency during submaximal leg extension in recreationally active males.
... In two of the selected studies [113,114], the influence of acute BR ingestion was assessed by adminstering 1 × 70 mL of BR (~6.4 mmol of NO3 -per 70 mL) ~2 h prior to the commencement of exercise. In the remaining two studies [115,116], longer-term (≥ 3 days) dosing strategies of NO3supplementation were employed. Mosher et al. [116] administered 1 × 70 mL of BR per day (~6.4 mmol of NO3 -per 70 mL) for 6 consecutive days, although the authors did not report the timing of ingestion, which has important implications for the elevation of plasma NO3 -and NO2 - [64]. ...
... In the remaining two studies [115,116], longer-term (≥ 3 days) dosing strategies of NO3supplementation were employed. Mosher et al. [116] administered 1 × 70 mL of BR per day (~6.4 mmol of NO3 -per 70 mL) for 6 consecutive days, although the authors did not report the timing of ingestion, which has important implications for the elevation of plasma NO3 -and NO2 - [64]. Flanagan et al. [115] administered 2 × NO3 --rich performance bars (32.5 mg of NO3 -per two bars) for 3 To ensure that the selection of studies assessed the effects of NO 3 − supplementation on weightlifting exercise performance, the authors applied a set of inclusion criteria [112]: ...
... The exercise modalities used to assess weightlifting exercise performance were bench press using free weights [113], bench press using a Smith machine [114,116] and box squats using a Smith machine [114,115]. The details of the performance tests employed are summarized in Table 1. ...
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Dietary nitrate (NO 3 −) supplementation has been evidenced to induce an ergogenic effect in endurance and sprint-type exercise, which may be underpinned by enhanced muscle contractility and perfusion, particularly in type II muscle fibers. However, limited data are available to evaluate the ergogenic potential of NO 3 − supplementation during other exercise modalities that mandate type II fiber recruitment, such as weightlifting exercise (i.e., resistance exercise). In this systematic review, we examine the existing evidence basis for NO 3 − supplementation to improve muscular power, velocity of contraction, and muscular endurance during weightlifting exercise in healthy adults. We also discuss the potential mechanistic bases for any positive effects of NO 3 − supplementation on resistance exercise performance. Dialnet, Directory of Open Access Journals, Medline, Pubmed, Scielo, Scopus and SPORT Discus databases were searched for articles using the keywords: nitrate or beetroot and supplement or nut*r or diet and strength or "resistance exercise" or "resistance training" or "muscular power". Four articles fulfilling the inclusion criteria were identified. Two of the four studies indicated that NO 3 − supplementation could increase aspects of upper body weightlifting exercise (i.e., bench press) performance (increases in mean power/velocity of contraction/number of repetitions to failure), whereas another study observed an increase in the number of repetitions to failure during lower limb weightlifting exercise (i.e., back squat). Although these preliminary observations are encouraging, further research is required for the ergogenic potential of NO 3 − supplementation on weightlifting exercise performance to be determined.
... Kramer et al. (23) found 6 days of potassium nitrate supplementation to enhance peak Wingate power, but not a timed resistance exercise protocol. Mosher et al. (30) used a crossover design to compare the effects of a BEET supplement containing 400 mg of nitrate on muscular endurance, defined as bench press repetitions completed over 3 sets to failure, demonstrating improved volume (total weight lifted), with no effect on blood lactate. Although this finding has yet to be replicated, evidence suggests that the ergogenic effects of BEET may be pronounced in high-intensity activities that rely on the recruitment of type II muscle fibers, such as resistance exercise. ...
... If substantial alterations occur in urea cycle function or aerobic energy production, such effects would likely be reflected by differences in postexercise urea and lactate accumulation, respectively. With only 1 study to date assessing traditional resistance training outcomes after the consumption of dietary nitrate (BEET) (30), its effects remain uncertain in the absence of replication. ...
... This finding was later supported by studies showing improved upper-body RTF (38) and lower-body RTF (39) in resistance-trained men and women (16). A single study has previously evaluated the effects of BEET on traditional dynamic constant external resistance exercise, with a significant increase in bench press RTF observed in resistance-trained men (30). By contrast, the current study found no such benefit on isokinetic leg extension, despite causing a marked increase in pre-exercise plasma NO x levels. ...
Article
Trexler, ET, Keith, DS, Schwartz, TA, Ryan, ED, Stoner, L, Persky, AM, and Smith-Ryan, AE. Effects of citrulline malate and beetroot juice supplementation on blood flow, energy metabolism, and performance during maximum effort leg extension exercise. J Strength Cond Res XX(X): 000-000, 2019-Citrulline malate (CitMal) and beetroot juice (BEET) are increasingly popular ergogenic aids, but few studies have rigorously investigated their effects on resistance exercise performance and underlying mechanisms. The current randomized, double-blind, crossover study evaluated the effects of CitMal and BEET supplementation on blood flow, metabolic efficiency, and performance during maximal isokinetic leg extension exercise. After familiarization, 27 recreationally active men (age: 22 ± 4 years) completed 3 visits in which subjects ingested a treatment beverage (CitMal [8 g], BEET [400-mg nitrate], or placebo [PLA]), followed by a 2-hour rest period, warm-up, and 5 sets of 30 concentric leg extensions. Before and after exercise, ultrasound was used to measure diameter (aDIAM) and blood flow (aBF) of the superficial femoral artery, along with cross-sectional area and echo intensity of the vastus lateralis. Plasma analytes (lactate, nitrate/nitrite [NOx], and urea nitrogen [BUN]) were also assessed at these times, and indirect calorimetry was used to measure energy expenditure and respiratory exchange ratio before and during exercise. Resting NOx values were higher in BEET (233.2 ± 1.1 μmol·L) compared with CitMal (15.3 ± 1.1, p < 0.0001) and PLA (13.4 ± 1.1, p < 0.0001). Postexercise NOx values, adjusted for resting differences, were higher in BEET (86.3 ± 1.2 μmol·L) than CitMal (21.3 ± 1.1, p < 0.0001) and PLA (18.1 ± 1.1, p < 0.0001). No other variables were affected by treatment (all p > 0.05). While BEET increased NOx, neither treatment was found to enhance performance, blood flow, metabolic efficiency, nor the hormonal response to leg extension exercise.
... Estos efectos podrían explicar las mejoras en los niveles de potencia máxima en una prueba con un predominio del metabolismo no oxidativo como es el test de Wingate Dominguez, Garnacho-Castano, et al., 2017). Recientemente, una revisión sistemática ha concluido que la suplementación con ZR presenta un efecto ergogénico en esfuerzos explosivos e intermitentes de alta intensidad , si bien en dicho trabajo únicamente se incluyó un trabajo que había valorado los efectos de la suplementación con ZR sobre el rendimiento en fuerza muscular (Mosher, Sparks, Williams, Bentley, & Mc Naughton, 2016). El entrenamiento de fuerza, a medio y largo plazo, provoca adaptaciones estructurales y neuromusculares (Crewther, Cronin, & Keogh, 2006) que incrementa los niveles de hipertrofia, fuerza y potencia muscular (Smith et al., 2014), al tiempo que previene la aparición de lesiones deportivas (Lauersen, Andersen, & Andersen, 2018). ...
... El tamaño muestral de los 14 artículos incluidos en la revisión asciende a 213 participantes de los cuales 181 pertenecen al género masculino y 32 al femenino. Diez estudios (Bender et al., 2018;Flanagan et al., 2016;Fulford et al., 2013;Haider & Folland, 2014;Kokkinoplitis & Chester, 2014;Mosher et al., 2016;Tillin, Moudy, Nourse, & Tyler, 2018;Trexler et al., 2019;Whitfield et al., 2017) fueron realizados exclusivamente con hombres, mientras que 3 (Coggan et al., 2019;Lee, Abel, Thomas, Symons, & Yates, 2019) incluyeron una muestra conformada por participantes de ambos géneros y un estudio incluyó únicamente participantes del género femenino (Wickham et al., 2019). En relación a las características de la muestra, 12 artículos analizaron a población adulta Flanagan et al., 2016;Fulford et al., 2013;Haider & Folland, 2014;Kokkinoplitis & Chester, 2014;Lee et al., 2019;Mosher et al., 2016;Tillin et al., 2018;Trexler et al., 2019;Whitfield et al., 2017;Wickham et al., 2019), un estudio a adolescentes (Bender et al., 2018) y otro a sujetos de edad avanzada . ...
... Diez estudios (Bender et al., 2018;Flanagan et al., 2016;Fulford et al., 2013;Haider & Folland, 2014;Kokkinoplitis & Chester, 2014;Mosher et al., 2016;Tillin, Moudy, Nourse, & Tyler, 2018;Trexler et al., 2019;Whitfield et al., 2017) fueron realizados exclusivamente con hombres, mientras que 3 (Coggan et al., 2019;Lee, Abel, Thomas, Symons, & Yates, 2019) incluyeron una muestra conformada por participantes de ambos géneros y un estudio incluyó únicamente participantes del género femenino (Wickham et al., 2019). En relación a las características de la muestra, 12 artículos analizaron a población adulta Flanagan et al., 2016;Fulford et al., 2013;Haider & Folland, 2014;Kokkinoplitis & Chester, 2014;Lee et al., 2019;Mosher et al., 2016;Tillin et al., 2018;Trexler et al., 2019;Whitfield et al., 2017;Wickham et al., 2019), un estudio a adolescentes (Bender et al., 2018) y otro a sujetos de edad avanzada . A excepción de una investigación en la que los participantes fueron sujetos con insuficiencia cardíaca , en el resto de investigaciones se incluyó a población sana de los cuales en 4 estudios se analizó a sujetos desentrenados (Coggan et al., 2019;Haider & Folland, 2014) y 9 a sujetos físicamente activos (Bender et al., 2018;Flanagan et al., 2016;Fulford et al., 2013;Lee et al., 2019;Mosher et al., 2016;Tillin et al., 2018;Trexler et al., 2019;Whitfield et al., 2017;Wickham et al., 2019), siendo la muestra de 2 de esos estudios sujetos entrenados en fuerza (Flanagan et al., 2016;Mosher et al., 2016). ...
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El zumo de remolacha (ZR) es una fuente nutricional rica en nitrato (NO3-) que, una vez ingerido, es reducido a óxido nítrico (ON). El ON posee efectos hipotensores, anti-inflamatorios y provoca mejoras en la eficiencia mitocondrial y en la regulación de la contractilidad muscular. Distintas investigaciones han comprobado que la suplementación con ZR presenta un efecto ergogénico en modalidades de resistencia cardiorrespiratoria y esfuerzos explosivos e intermitentes de alta intensidad. Sin embargo, dado que ninguna revisión ha valorado el efecto de la suplementación con ZR sobre la producción de fuerza muscular, el objetivo de la presente revisión sistemática es analizar el efecto de la suplementación con ZR sobre el rendimiento en la fuerza muscular. La búsqueda mediante palabras clave y conectores booleanos se realizó en las bases de datos Dialnet, Directory of Open Access Journals, Medline, Pubmed, Scielo, Scopus y SPORTDiscus. La estrategia de búsqueda empleada fue la siguiente: (nitrate OR beet*) AND (concepto 2) (supplement* OR nutr* OR diet*) AND (concepto 3) (strength OR "resistance exercise" OR "resistance training" OR "muscular power"). Tras la aplicación de los criterios de inclusión, un total de 14 artículos fueron seleccionados para la revisión. En la revisión se ha comprobado como la suplementación con ZR puede tener un efecto ergogénico sobre la producción de fuerza muscular bajo estimulación eléctrica, así como sobre la producción de potencia sobre contracciones isocinéticas únicamente a altas velocidades angulares, siendo el mecanismo explicativo una potenciación de la capacidad contráctil específicamente en las fibras musculares tipo II. Abstract. Beet juice (BJ) is a nutritional source rich in nitrate (NO3-) which, after ingestion, is reduced to nitric oxide (NO). NO has effects such as reduction in arterial pressure, anti-inflammatory effects, enhancement of mitochondrial efficiency, and regulation of muscle contractility. Different studies have reported that BJ supplementation has an ergogenic effect in modalities of cardiorespiratory endurance and explosive and intermittent high intensity efforts. Nevertheless, no review has assessed the effect of BJ supplementation on muscle strength production. Thus, the objective of this systematic review is to analyse the effect of BJ supplementation on muscle strength performance. The search using keywords and Boolean connectors was carried out in the databases Dialnet, Directory of Open Access Journals, Medline, Pubmed, Scielo, Scopus, and SPORTDiscus. The search strategy used was the following: (nitrate OR beet *) AND (concept 2) (supplement * OR nutr * OR diet *) AND (concept 3) (strength OR "resistance exercise" OR "resistance training" OR "muscular power "). After the application of the inclusion criteria, a total of 14 articles were selected for review. The review has shown how BJ supplementation can have an ergogenic effect on the production of muscle strength under electrical stimulation, as well as on the production of power over isokinetic contractions only at high angular speeds, the explanatory mechanism being a potentiation of the contractile capacity specifically in type II muscle fibers.
... A single dose of BRJ has been shown to improve peak (Dom ınguez et al. 2017;Cuenca et al. 2018;Jodra et al. 2020;Kramer et al. 2016) and mean (Cuenca et al. 2018) power during a 30second Wingate anaerobic test (WAnT) while reducing subjective measures of muscular fatigue (Dom ınguez et al. 2017) in recreationally-trained males. With regards to resistance exercise, Mosher et al. (2016) reported an improvement in bench press repetitions to fatigue after participants consumed NO 3 rich BRJ. These findings were most recently supported by Williams et. ...
... Based on pharmacokinetic data which reported peak NO 2 and NO 3 plasma concentrations at 30 min, we postulated that each athlete would finish their warm-up and begin their working sets $30 min post-consumption at peak NO 2 and NO 3 levels. Given recent work reporting improved resistance exercise volume (Williams et al. 2020;Mosher et al. 2016) and explosive power (Williams et al. 2020) in the bench press following acute or shortterm NO 3 consumption, we postulated that RSE may improve workout quality and thus enhance adaptations following training. Nevertheless, we observed no significant improvements in 1RM strength in the bench press exercise. ...
... The absolute dose of NO 3 administered in our study (180 mg) is lower than many investigations which show an improvement in acute resistance exercise performance or force production employing a NO 3 dose ! 400 mg (Mosher et al. 2016;Bender et al. 2018;Williams et al. 2020). However, lower doses of NO 3 -(90 mg) via RSE administration (1 g) have been shown to augment aerobic exercise performance (Gonzalez et al. 2019;Moore et al. 2017) and 180 mg of NO 3 via RSE (Subramanian and Gupta 2016) elevated plasma NO 3 and NO 2 to concentrations similar to those seen following larger doses ($12mmol) of BRJ consumption (Wylie et al. 2019;Coggan et al. 2018). ...
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Purpose To determine the effects of dietary nitrate supplementation, in the form of red spinach extract (RSE), on adaptations to offseason training in collegiate athletes. Methods: Sixteen Division I male baseball athletes (20.5 ± 1.7y, 90.4 ± 0.5 kg) enrolled in this study and were randomized into a RSE (n = 8) or placebo (n = 8; PL) group. Athletes completed an 11-week resistance training program during the offseason, which consisted of 2-3 workouts per week of upper and lower-body exercises and baseball-specific training. Athletes consumed a RSE (2 g; 180 mg nitrate) or PL supplement daily for the entire offseason training program. Pre and post-training, all athletes underwent one-repetition maximum (1RM) strength testing for the bench press and completed a Wingate anaerobic cycle test (WAnT). Body composition analysis was completed via a 4-compartment model, as well as muscle thickness (MT) measurement of the rectus femoris (RF) and vastus lateralis (VL) via ultrasonography. Resting heart rate and blood pressure (BP) were also obtained. Separate repeated measures analyses of variance were used to analyze all data. Results: Significant (p ≤ 0.05) main effects for time were observed for improved bench 1RM, fat-free mass, body fat percentage, RF MT, and VL MT. No significant group x time interactions (p > 0.05) were found for any measure of performance, body composition, or cardiovascular health. However, a trend for improved peak power in the WAnT was observed (p = 0.095; η²=0.200). Conclusions: These data suggest that daily RSE supplementation had no effect on performance, body composition, or cardiovascular measures in male Division I baseball players following offseason training.
... In addition, a growing body of preliminary research has suggested that dietary nitrate supplementation enhances high-intensity sprint performance [7,63À65]. One recent study [66] investigated the effects of beetroot juice supplementation on a resistance exercise test consisting of three sets of bench presses taken to concentric failure, with a load equivalent to 60% of the 1 RM. Participants completed significantly more repetitions and lifted more total weight in the beetroot condition than in the placebo group. ...
... In this study, no between-treatment differences were seen in blood lactate or perceived exertion. Thus, the acute effects of dietary nitrate supplementation seem to positively affect exercise performance in high-intensity anaerobic, aerobic [53,57], and resistance training modalities [66]. The possible mechanisms of action responsible for those improvements are increased blood flow [58], increased mitochondrial efficiency, oxygen utilization, and enhanced muscle contractile properties [41,54,55]. ...
... The possible mechanisms of action responsible for those improvements are increased blood flow [58], increased mitochondrial efficiency, oxygen utilization, and enhanced muscle contractile properties [41,54,55]. Although alterations in anaerobic metabolism are thought to contribute to improvements in resistance training performance, changes in blood lactate concentrations were not observed in the supra-cited study [66]. On the other hand, the ingestion of dietary nitrates has been shown to increase muscle blood flow and local oxygen consumption via local vasodilation during one set of moderate-and high-intensity handgrip exercise [67]. ...
Article
Increased blood flow via vasodilation, metabolite production, and venous pooling contribute to the hyperaemia and cellular swelling experienced during resistance training. These effects have been suggested to play a role in hypertrophic adaptations. Over the past two decades sport supplement products have been marketed to promote exercise hyperaemia and intracellular fluid storage, and thereby enhance hypertrophy via acute swelling of myocytes. The three main classes of supplements hypothesized to promote exercise-induced hyperaemia include: vasodilators, such as nitric oxide precursor supplements; anaerobic energy system ergogenic aids that increase metabolite production, such as beta-alanine and creatine; and organic osmolytes, such as creatine and betaine. Previous studies indicated that these dietary supplements are able to improve muscle performance and thus enhance muscle hypertrophy; however, recent evidences also point to these three classes of supplements affecting “secondary” physiological determinants of muscle mass accretion such as vasodilation, metabolite accumulation and muscle cellular swelling. Although we recognize that the literature is relatively scarce regarding these topics, a better comprehension and discussion of these determinants can lead to increased knowledge and guide further research regarding the proposed mechanisms of action of the identified compounds. In this case, increased knowledge may contribute to the development of improved efficacy, new products, or direct new research to specifically investigate those secondary effects. From this discussion, new perspectives associated with “secondary physiological effects” induced by supplementation will be brought into focus and its relevance will be determined.
... Such effects of NO could mean a physiological advantage for efforts involving the recruitment of type II muscle fibres, such as intermittent, high-intensity efforts. Hence, given the scarce yet growing number of studies that have addressed the effects of beetroot juice supplementation on this type of intermittent, high-intensity effort [38,[53][54][55][56][57][58][59][60], here we review the results of experimental studies that have specifically examined in adults (whether athletes or not) the effects of beetroot juice supplementation on intermittent, high-intensity efforts. ...
... In the remaining four studies, the effects of chronic beetroot juice supplementation were examined [55,56,58,60]. The supplementation periods were 5 days in one study [60], 6 days in two [55,58] and 7 days in the fourth study [56]. ...
... In the remaining four studies, the effects of chronic beetroot juice supplementation were examined [55,56,58,60]. The supplementation periods were 5 days in one study [60], 6 days in two [55,58] and 7 days in the fourth study [56]. ...
Article
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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.
... In the former studies, the acute nitrate dose was administered 120 minutes to 4 hours before the exercise test (18,23,27,28,37). In the 7 studies examining the effects of chronic SUP, nitrate doses were given from 4 to 15 days before exercise testing (7,10,12,16,22,26,29). The nitrate source was beetroot juice or gel in 9 studies (7,10,12,18,22,23,27,28,37), a nitrate capsule in 1 study (16), and increased total nitrate intake through diet manipulation in 2 studies (26,29). ...
... In the 7 studies examining the effects of chronic SUP, nitrate doses were given from 4 to 15 days before exercise testing (7,10,12,16,22,26,29). The nitrate source was beetroot juice or gel in 9 studies (7,10,12,18,22,23,27,28,37), a nitrate capsule in 1 study (16), and increased total nitrate intake through diet manipulation in 2 studies (26,29). The doses given in the studies varied based on the SUP protocol. ...
... Four studies worked with 24-hour (27), 48-hour (10), 72hour (16), or 1-week (26) diet recalls. In another 4 studies, subjects were only instructed to follow their normal diet for either the entirety of the study (7) or the day preceding exercise testing (22,28,37). ...
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Anderson, OK, Martinez-Ferran, M, Lorenzo-Calvo, J, Jiménez, SL, and Pareja-Galeano, H. Effects of nitrate supplementation on muscle strength and mass: a systematic review. J Strength Cond Res XX(X): 000–000, 2021—This systematic review examines the effect of dietary nitrate supplementation (SUP) on muscle strength and hypertrophy when combined with physical exercise. The databases PubMed, Web of Science, and MEDLINE were searched for full-text articles published between January 2000 and June 2020. For inclusion, studies had to report on the effects of SUP administered as acute or chronic doses together with a standardized exercise protocol on muscle strength and hypertrophy compared with placebo in healthy adults who were sedentary, physically active, or professional athletes. Twelve studies (1,571 subjects) were finally selected. In 5 studies, the SUP regime was acute, and in 7, it was chronic. SUP was nitrate-rich beetroot juice in 9 studies, a potassium nitrate capsule in 1, and increased dietary nitrate in 2. Ingested nitrate was 64–1,200 mg. Of the 12 studies, 6 observed an ergogenic effect of SUP compared with placebo. These findings indicate that muscle strength gains are possible provided the dose, format, frequency, period, and exercise test are appropriate. Best results were observed with a minimum acute dose of 400 mg of nitrate provided as beetroot juice/shot taken 2–2.5 hours before exercise involving low- and high-intensity muscle contractions. This SUP regime seems to improve muscle efficiency in terms of reduced phosphocreatine and energy costs (P-magnetic resonance spectroscopy) and improved time to exhaustion.
... However, 210 mL of juice (19.5 mmol~1.1 g of NO 3 − ) both for one day (acute) and for 8 days (chronic) before completion of a submaximal treadmill run and 1500 m time trial (aerobic power) did not reduce VO 2 nor time-trial in a group of elite distance runners [24]. On the other hand, NO 3 − could play a key role in anaerobic exercises, maximal strength or endurance-strength performance [25,26]. Besides, the contractile characteristics of human muscle are improved by dietary NO 3 − [27]. ...
... Therefore, Nyakayiru et al. reported that 140 mL of BR juice supplementation 2.5 h before exercise improved isometric force production [30]. In addition, other studies presented positive results in achieving a greater number of repetitions of bench press by ingesting a drink (400 mg of NO 3 − ) for 6 days [26]. In this regard, BR supplementation may improve mitochondrial efficiency [31] and/or reduce the cost of ATP in both maximal and endurance-strength performance production [32]. ...
... The use of nutritional supplements to improve sports performance is becoming increasingly widespread among triathletes [54,55]. In this regard, CIT [12][13][14][15]17] and BR (NO precursors) [23,25,26,[30][31][32] are two nutritional supplements that could help improve performance in both exercises, involving neuromuscular strength and endurance [56,57]. It has been shown that NO can help athletes with functions that are closely involved in the regulation of muscle contraction, blood flow, maximal oxygen consumption during exercise, adaptations at the mitochondrial level and homeostasis of glucose and calcium [27,[57][58][59], which in the long term can improve athletic performance [60]. ...
Article
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Citrulline (CIT) and nitrate-rich beetroot extract (BR) are ergogenic aids and nitric oxide (NO) precursors. In addition, both supplements seem to have other actions at the level of muscle metabolism that can benefit strength and aerobic power performance. Both supplements have been studied in numerous investigations in isolation. However, scientific evidence combining both supplements is scarce, and to the best of the authors’ knowledge, there is no current study of endurance athletes. Therefore, the main purpose of this study was to determine the effect of 9 weeks of CIT plus BR supplementation on maximal and endurance-strength performance and aerobic power in male triathletes. This study was a randomized double-blind, placebo-controlled trial where participants (n = 32) were randomized into four different groups: placebo group (PLG; n = 8), CIT plus BR group (CIT- BRG; 3 g/kg/day of CIT plus 3 mg/kg/day of nitrates (NO3 −); n = 8), CIT group (CITG; 3 g/kg/day; n = 8) and BR group (BRG; 3 mg/kg/day of NO3−; n = 8). Before (T1) and after 9 weeks (T2), four physical condition tests were carried out in order to assess sport performance: the horizontal jump test (HJUMP), handgrip dynamometer test, 1-min abdominal tests (1-MAT) and finally, the Cooper test. Although, no significant interactions (time × supplementation groups) were found for the strength tests (p > 0.05), the CIT- BRG supplementation presented a trend on HJUMP and 1-MAT tests confirmed by significant increase between two study moments in CIT-BRG. Likewise, CIT-BRG presented significant interactions in the aerobic power test confirmed by this group’s improve estimated VO2max during the study with respect to the other study groups (p = 0.002; η 2p = 0.418). In summary, supplementing with 3 g/day of CIT and 2.1 g/day of BR (300 mg/day of NO3 −) for 9 weeks could increase maximal and endurance strength. Furthermore, when compared to CIT or BR supplementation alone, this combination improved performance in tests related to aerobic power.
... Originally, RPE was used to evaluate general intensity, and later, other studies applied it to the evaluation of local muscles. Mosher et al. measured the overall and the local RPE in order to explore the effects of nitrate intake on resistance training [15]. Mathew et al. measured the working muscles and the overall RPE of the subjects in their to compare the cardiorespiratory and perceptual responses to exercises using self-regulated and imposed power outputs distributed between the arms and legs [16]. ...
... The subjects were then asked to sit on the cycle ergometer (Monark 839 e, Vansbro, Sweden), and the seat and grip were adjusted to the proper height in order to carry out step incremental load test. The experiment consisted of a 5 min warm-up at a zero-load pace of 60 rpm, during which the participants became familiar with the equipment and listened to the instructions for Borg RPE Scale (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) test read by the professional conducting the test. The subjects described their self-perceived strenuousness and tiredness using the numbers from 6 to 15, with large numbers representing higher levels of fatigue [28]. ...
... Lee et al. believed that the evaluation of the exercise intensity with RPE (6-20) was moderately reliable [40]. Yang et al. believed that there might be some errors during the RPE (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) quantification of athletes with a low resting heart rate and a high reserve heart rate [8]. Based on the experiments conducted above, we hold that model errors probably result from the improper scale division selected for RPE. ...
Article
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The rating of perceived exertion (RPE) and surface electromyography (sEMG) describe exercise intensity subjectively and objectively, while there has been a lack of research on the relationship between them during dynamic contractions to predict exercise intensity, comprehensively. The purpose of this study was to establish a model of the relationship between sEMG and RPE during dynamic exercises. Therefore, 20 healthy male subjects were organized to perform an incremental load test on a cycle ergometer, and the subjects’ RPEs (Borg Scale 6–20) were collected every minute. Additionally, the sEMGs of the subjects’ eight lower limb muscles were collected. The sEMG features based on time domain, frequency domain and time–frequency domain methods were extracted, and the relationship model was established using Gaussian process regression (GPR). The results show that the sEMG and RPE of the selected lower limb muscles are significantly correlated (p < 0.05) but that they have different monotonic correlation degrees. The model that was established with all three domain features displayed optimal performance and when the RPE was 13, the prediction error was the smallest. The study is significant for lower limb muscle training strategy and quantification of training intensity from both subjective and objective aspects, and lays a foundation for sEMG further applications in rehabilitation medicine and sports training.
... 52 In terms of muscular endurance, it has been reported that BRJ supplements increase the number of repetitions until concentric failure, with load ranging from 60% to 80% 1RM on the upper and lower limbs. 45,66 To date, all the studies that have analyzed the effects of NO 3 supplementation on the CMJ and RT have recruited male participants. It has been proposed that in women, the reduction of NO 2 -to NO could be blunted, based on the fact that they have a greater oxidative skeletal muscle phenotype than men. ...
... Before attempting the protocols, the participants first completed a specific warm-up. Based on previous research, 45,66 the warm-up began with 10 minutes of pedaling on a cycle ergometer (the first 4 min at a free intensity and the following 6 min at 75% of maximum heart rate [Polar H10]). They then performed 1 warm-up set of the different exercises to be evaluated, but using very light weights. ...
... These results are in line with previous studies. 45,66 Indeed, our research group 52 observed an increase (+17.7%) in the total number of repetitions in a session comprising a set with a load of 60%, 70%, and 80% 1RM for bench presses and back squats after BRJ supplementation. In addition, Williams et al 66 reported an increase (+10.7%) in the maximum number of repetitions in 3 sets with a load of 70% 1RM, with a recovery of 2 minutes between sets on a bench press, whereas Mosher et al 45 reported an enhancement (+19.4%) with a load corresponding to 70% 1RM. ...
Article
Background Beetroot juice (BRJ) is used as an ergogenic aid, but no previous study has analyzed the effect this supplement has on the production of explosive force and muscular endurance in physically active women. Hypothesis BRJ improves explosive force and muscular endurance in the lower limbs of physically active women. Study design Randomized double-blind crossover study. Level of evidence Level 3 Methods Fourteen physically active women performed a countermovement jump (CMJ) test, a back squat test for assessing velocity and power at 50% and 75% of one-repetition maximum (1RM), and the number of repetitions on a muscular endurance test consisting of 3 sets at 75% of 1RM in a resistance training protocol comprising 3 exercises (back squat, leg press, and leg extension). The participants performed the test in 2 sessions, 150 minutes after ingesting 70 mL of either BRJ (400 mg of nitrate) or a placebo (PLA). Results A greater maximum height was achieved in the CMJ after consuming BRJ compared with a PLA ( P = 0.04; effect size (ES) = 0.34). After a BRJ supplement at 50% 1RM, a higher mean velocity [+6.7%; P = 0.03; (ES) = 0.39 (–0.40 to 1.17)], peak velocity (+6%; P = 0.04; ES = 0.39 [−0.40 to 1.17]), mean power (+7.3%; P = 0.02; ES = 0.30 [−0.48 to 1.08]) and peak power (+6%; P = 0.04; ES = 0.20 [−0.59 to 0.98]) were attained in the back squat test. In the muscular endurance test, BRJ increased performance compared with the PLA ( P < 0.00; η p ² = 0.651). Conclusion BRJ supplements exert an ergogenic effect on the ability to produce explosive force and muscular endurance in the lower limbs in physically active women. Clinical relevance If physically active women took a BRJ supplement 120 minutes before resistance training their performance could be enhanced.
... (3) (17) Mosher et al. (48) Bailey et al. (18) Breese et al. (40) Wylie et al. ...
... No significant correlations were observed between the supplementation features evaluated and changes in physical performance. (43) Coggan et al. (2) (43) Fulford et al. (2) (45) Wylie et al. (2) (57) Buck et al. (41) Wylie et al. (3) (57) Coggan et al. (3) (43) Coggan et al. (4) (43) Wylie et al. (1) (57) Thompson et al. (53) Christensen et al. (2) (42) Kokkinoplitis and Chester (47) Fulford et al. (3) (45) Corry et al. (44) Kelly et al. (4) (46) Mosher et al. (48) Overall (I 2 = 0 . 0 %, P = 0 . ...
Article
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Nitrate (NO 3⁻ ) is an ergogenic nutritional supplement that is widely used to improve physical performance. However, the effectiveness of NO 3⁻ supplementation has not been systematically investigated in individuals with different physical fitness levels. The present study analysed whether different fitness levels (non-athletes v . athletes or classification of performance levels), duration of the test used to measure performance (short v. long duration) and the test protocol (time trials v. open-ended tests v. graded-exercise tests) influence the effects of NO 3⁻ supplementation on performance. This systematic review and meta-analysis was conducted and reported according to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. A systematic search of electronic databases, including PubMed, Web of Science, SPORTDiscus and ProQuest, was performed in August 2017. On the basis of the search and inclusion criteria, fifty-four and fifty-three placebo-controlled studies evaluating the effects of NO 3⁻ supplementation on performance in humans were included in the systematic review and meta-analysis, respectively. NO 3⁻ supplementation was ergogenic in non-athletes (mean effect size (ES) 0·25; 95 % CI 0·11, 0·38), particularly in evaluations of performance using long-duration open-ended tests (ES 0·47; 95 % CI 0·23, 0·71). In contrast, NO 3⁻ supplementation did not enhance the performance of athletes (ES 0·04; 95 % CI −0·05, 0·15). After objectively classifying the participants into different performance levels, the frequency of trials showing ergogenic effects in individuals classified at lower levels was higher than that in individuals classified at higher levels. Thus, the present study indicates that dietary NO 3⁻ supplementation improves physical performance in non-athletes, particularly during long-duration open-ended tests.
... Blood lactate concentrations are considered to indicate the glycolytic contribution to energy metabolism [54], though the transfer of lactate to the bloodstream depends on the extent of capillarization and muscle perfusion. In a 30-s maximum load test such as the Wingate, in which type II motorneurons are recruited and there is a highly glycolytic metabolism, blood lactate concentrations are much lower than those of muscle lactate and several minutes are needed for blood and muscle concentrations to reach a balance [58]. It is possible that increased blood flow to type II motor units following BJ supplementation [5], could have led to increased blood lactate concentrations [59]. ...
... This mechanism could explain the ergogenic effect of this supplement detected in our study and in others [54]. Wylie et al. [56] observed increased blood lactate levels along with improved performance at a cycle ergometer protocol consisting of 24 sets of 6 s and 24-s rest periods, while Mosher et al. [58] noted an increased number of repetitions accomplished until exhaustion when lifting a load equivalent to 60% of one maximum repetition (1 RM) during bench press exercise. As the impacts on power output of BJ supplementation are attributed to the improved performance of type II motor units characterized by a greater dependence on glycolytic energy metabolism, this leads to a greater increase in blood lactate following the exercise effort [59]. ...
Article
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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.
... In contrast, few studies have evaluated the effects of nitrate on resistance exercise. Mosher et al. (2016) found six days of beetroot juice supplementation (containing 400 mg nitrate per dose) enhanced bench press repetitions to fatigue over three sets taken to failure. Similarly, beetroot juice enhanced leg extension speed and power (Coggan et al., 2015), in addition to explosive force production in fatigued muscle (Tillin et al., 2018). ...
Article
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The popularity of physique sports is increasing, yet there are currently few comprehensive nutritional guidelines for these athletes. Physique sport now encompasses more than just a short phase before competition and offseason guidelines have recently been published. Therefore, the goal of this review is to provide an extensive guide for male and female physique athletes in the contest preparation and recovery period. As optimal protein intake is largely related to one’s skeletal muscle mass, current evidence supports a range of 1.8-2.7 g/kg. Furthermore, as a benefit from having adequate carbohydrate to fuel performance and activity, low-end fat intake during contest preparation of 10-25% of calories allows for what calories remain in the “energy budget” to come from carbohydrate to mitigate the negative impact of energy restriction and weight loss on training performance. For nutrient timing, we recommend consuming four or five protein boluses per day with one consumed near training and one prior to sleep. During competition periods, slower rates of weight loss (≤0.5% of body mass per week) are preferable for attenuating the loss of fat-free mass with the use of intermittent energy restriction strategies, such as diet breaks and refeeds, being possibly beneficial. Additionally, physiological and psychological factors are covered, and potential best-practice guidelines are provided for disordered eating and body image concerns since physique athletes present with higher incidences of these issues, which may be potentially exacerbated by certain traditional physique practices. We also review common peaking practices, and the critical transition to the post-competition period.
... Several studies have been showed that improvement of performance with BJ linked to a reduced PCr decrease lead to improve energy system. 16,17 In the present study, we examined the effects of BJ supplementation on anaerobic performance, in a arm Wingate test, and recovery level of elite boxers. ...
Article
BACKGROUND: Beetroot juice (BJ) has been recently used by athletes for improving sports performance. BJ is supported by studies that increase the aerobic power, but the effects on anaerobic power are still controversial. Therefore, the purpose of this study was to investigate the effects of acute dietary nitrate (red beetroot juice) supplementation on arm anaerobic power parameters, fatigue and recovery levels in elite male boxers. METHODS: Using a single-blind, repeated-measures crossover design (5 days washout period), eight elite male boxers (23±2.28 years, 174.83±11 cm, 76.66±19.37 kg, experience: 10.5±0.5 years and still active) participated as volunteers in the study. Participants were undertaken a 30-s anaerobic Wingate Test after consuming BJ (2 g/kg body weight) or placebo (PLA). Heart rate (HR) and capillary blood lactate levels were measured before and immediately after the Wingate test (fatigue) besides that HR and lactate levels were recorded at 10th, 15th, 30th, 60th, 90th minutes for following the recovery levels of participants. RESULTS: Despite no effects of BJ on the blood lactate levels and heart rate (except fatigue time), significant decline was found on peak power, relative peak power, mean power and relative mean power for BJ (P<0.05). CONCLUSIONS: These results suggest that acute dietary nitrate supplementation has not a positive effects on anaerobic power or recovery of elite male boxers. KEY WORDS: �Fatigue; Nitrates; Boxing.
... Notably, these chemical compounds appear to assist in elevating circulating levels of NO 2 − and, therefore, harness the potential to improve vascular compliance [83][84][85] Recently, a large collection of literature has demonstrated the efficacy of BRJ in elevating levels of plasma NO 2 − (and, therefore, the potential for O 2 independent NO production) to increase skeletal muscle blood flow, slow the reduction in microvascular O 2 partial pressure (PO 2 ), reduce O 2 uptake (VO 2 ) [86][87][88], lower exercise mean arterial oxygen saturation (Sa O 2 ) [89], and improve cognitive performance during exercise [87,90]. Moreover, these performance enhancing effects have been observed across multiple exercise disciplines (water sports [89,91,92], running [86,90,93], cycling [87], and strength-based activities [94,95] performed at varying intensities (high [86,90,91,93], moderate [88,92], and low [89,95]) and within several contrasting environments (below sea level [89], hyper-thermic conditions [96], and altitude [88]). Despite these findings, research has so far failed to identify any improvements in either blood pressure or exercise performance outcomes following four days dosing of BRJ (6.43 mmol·L −1 NO 3 − ) in people with T1D. ...
Article
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Type 1 diabetes (T1D) is associated with a greater occurrence of cardiovascular pathologies. Vascular dysfunction has been shown at the level of the endothelial layers and failure to maintain a continuous pool of circulating nitric oxide (NO) has been implicated in the progression of poor vascular health. Biochemically, NO can be produced via two distinct yet interrelated pathways that involve an upregulation in the enzymatic activity of nitric oxide synthase (NOS). These pathways can be split into an endogenous oxygen-dependent pathway i.e., the catabolism of the amino acid L-arginine to L-citrulline concurrently yielding NO in the process, and an exogenous oxygen-independent one i.e., the conversion of exogenous inorganic nitrate to nitrite and subsequently NO in a stepwise fashion. Although a body of research has explored the vascular responses to exercise and/or compounds known to stimulate NOS and subsequently NO production, there is little research applying these findings to individuals with T1D, for whom preventative strategies that alleviate or at least temper vascular pathologies are critical foci for long-term risk mitigation. This review addresses the proposed mechanisms responsible for vascular dysfunction, before exploring the potential mechanisms by which exercise, and two supplementary NO donors may provide vascular benefits in T1D.
... Clifford and coworkers [40] reported that beetroot juice ingestion reduced the decrement in jumping performance and reactive strength index following repeated sprint training. Mosher et al. [41] reported that nitrate supplementation (400 mg) increased the number of repetitions performed to failure and total work performed during resistance training. Finally, beetroot ingestion has been reported to enhance repetitive sprint performance [37,38]. ...
Article
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In a double-blind, crossover, randomized and placebo-controlled trial; 28 men and women ingested a placebo (PLA), 3 g of creatine nitrate (CNL), and 6 g of creatine nitrate (CNH) for 6 days. Participants repeated the experiment with the alternate supplements after a 7-day washout. Hemodynamic responses to a postural challenge, fasting blood samples, and bench press, leg press, and cycling time trial performance and recovery were assessed. Data were analyzed by univariate, multivariate, and repeated measures general linear models (GLM). No significant differences were found among treatments for hemodynamic responses, clinical blood markers or self-reported side effects. After 5 days of supplementation, one repetition maximum (1RM) bench press improved significantly for CNH (mean change, 95% CI; 6.1 [3.5, 8.7] kg) but not PLA (0.7 [−1.6, 3.0] kg or CNL (2.0 [−0.9, 4.9] kg, CNH, p = 0.01). CNH participants also tended to experience an attenuated loss in 1RM strength during the recovery performance tests following supplementation on day 5 (PLA: −9.3 [−13.5, −5.0], CNL: −9.3 [−13.5, −5.1], CNH: −3.9 [−6.6, −1.2] kg, p = 0.07). After 5 days, pre-supplementation 1RM leg press values increased significantly, only with CNH (24.7 [8.8, 40.6] kg, but not PLA (13.9 [−15.7, 43.5] or CNL (14.6 [−0.5, 29.7]). Further, post-supplementation 1RM leg press recovery did not decrease significantly for CNH (−13.3 [−31.9, 5.3], but did for PLA (−30.5 [−53.4, −7.7] and CNL (−29.0 [−49.5, −8.4]). CNL treatment promoted an increase in bench press repetitions at 70% of 1RM during recovery on day 5 (PLA: 0.4 [−0.8, 1.6], CNL: 0.9 [0.35, 1.5], CNH: 0.5 [−0.2, 0.3], p = 0.56), greater leg press endurance prior to supplementation on day 5 (PLA: −0.2 [−1.6, 1.2], CNL: 0.9 [0.2, 1.6], CNH: 0.2 [−0.5, 0.9], p = 0.25) and greater leg press endurance during recovery on day 5 (PLA: −0.03 [−1.2, 1.1], CNL: 1.1 [0.3, 1.9], CNH: 0.4 [−0.4, 1.2], p = 0.23). Cycling time trial performance (4 km) was not affected. Results indicate that creatine nitrate supplementation, up to a 6 g dose, for 6 days, appears to be safe and provide some ergogenic benefit.
... Nitric oxide (NO) is an important messenger molecule and effector molecule in the body and is closely related to pathological and physiological processes of the nervous system (Stoyanova and Lazarov, 2005). For example, NO in the hippocampus participates in the learning and memory process as a neurotransmitter (Mosher et al., 2016;Andrade Próspero et al., 2018;Berenyiova et al., 2018). The overtraining syndrome after chronic exhaustive exercise is related to the expression of NO and NO synthase (NOS; Lee et al., 2012). ...
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The inducible nitric oxide synthase/nitric oxide (iNOS/NO) signaling pathway and inflammatory cytokines play important roles in the pathogenesis of exercise-induced fatigue. Studies have found that Mongolian warm acupuncture (WA) could alleviate exercise-induced fatigue. However, the exact mechanisms underlying its effects remain unclear. In the present study, we investigated the effects of Mongolian WA on iNOS/NO signaling pathway and proinflammatory cytokines in a chronic exhaustive swimming-induced fatigue rat model. Animals were randomly divided into Control group, Ctrl + WA group, Model group, and Model + WA group. The body weight, exhaustive swimming time test, and Morris water maze test were performed before and after the chronic exhaustive swimming. The serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and iNOS were detected by enzyme linked immunosorbent assay (ELISA). The mRNA expressions of IL-1β, IL-6, TNF-α, IFN-γ, and iNOS in the hippocampus were measured by real-time polymerase chain reaction (RT-PCR). Moreover, the protein expression of iNOS in the hippocampus was measured by western blot, and the NO productions in the serum and hippocampus were detected by Griess reaction system. Chronic exhaustive exercise significantly reduced the body weight and exhaustive swimming time, and induced impairment in learning and memory, and which were reversed by WA treatment. Chronic exhaustive exercise also increased the expressions of iNOS and proinflammatory cytokines, while WA treatment significantly decreased the level of iNOS and proinflammatory cytokines. However, chronic exhaustive exercise did not affect the NO production. These findings demonstrated that WA could alleviate the chronic exhaustive swimming-induced fatigue and improve the learning and memory ability, and the actions might be related to the reduction of inflammatory response and iNOS expression.
... This may explain the more explicit effects of nitrate supplementation on performance during high-intensity exercise requiring greater input of type II fibers for production of high power outputs at high contraction velocities (Vanhatalo et al., 2011;Breese et al., 2013;Bailey et al., 2015;Coggan et al., 2015). Higher muscle blood flow during recovery (Alvares et al., 2012) could conceivably facilitate the clearance of waste metabolites during intermittent maximal exercise bouts and could, amongst the other aforementioned mechanism, contribute to increased total work output during resistance training (Mosher et al., 2016). Furthermore, nitrate supplementation in hypoxia was shown to stimulate the rate of post-exercise muscle PCr resynthesis (Vanhatalo et al., 2011. ...
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Purpose: We investigated the effect of sprint interval training (SIT) in normoxia, vs. SIT in hypoxia alone or in conjunction with oral nitrate intake, on buffering capacity of homogenized muscle (βhm) and fiber type distribution, as well as on sprint and endurance performance. Methods: Twenty-seven moderately-trained participants were allocated to one of three experimental groups: SIT in normoxia (20.9% FiO2) + placebo (N), SIT in hypoxia (15% FiO2) + placebo (H), or SIT in hypoxia + nitrate supplementation (HN). All participated in 5 weeks of SIT on a cycle ergometer (30-s sprints interspersed by 4.5 min recovery-intervals, 3 weekly sessions, 4–6 sprints per session). Nitrate (6.45 mmol NaNO3) or placebo capsules were administered 3 h before each session. Before and after SIT participants performed an incremental VO2max-test, a 30-min simulated cycling time-trial, as well as a 30-s cycling sprint test. Muscle biopsies were taken from m. vastus lateralis. Results: SIT decreased the proportion of type IIx muscle fibers in all groups (P < 0.05). The relative number of type IIa fibers increased (P < 0.05) in HN (P < 0.05 vs. H), but not in the other groups. SIT had no significant effect on βhm. Compared with H, SIT tended to enhance 30-s sprint performance more in HN than in H (P = 0.085). VO2max and 30-min time-trial performance increased in all groups to a similar extent. Conclusion: SIT in hypoxia combined with nitrate supplementation increases the proportion of type IIa fibers in muscle, which may be associated with enhanced performance in short maximal exercise. Compared with normoxic training, hypoxic SIT does not alter βhm or endurance and sprinting exercise performance.
... Evidence suggests that the NO3-pathway is more active in hypoxic and acidic conditions, which are the conditions that occur during intense exercise (42). These findings have sparked an upswing in research that examines the potential ergogenic impact of beet juice supplementation on supramaximal work (2,6,14,16,17,32,38). Repeated sprint protocols often utilize shortduration, high-intensity intervals to examine overall performance across exercise sessions (2,8,40). ...
Article
Research suggests that beet juice is beneficial during aerobic exercise. However, the impact of beet juice during primarily anaerobic exercise is equivocal. The purpose of this study was to determine the effects of acute beet juice supplementation on maximal intensity performance during 30-s and 60-s maximal-intensity cycling sprints. Using a double-blind, crossover-study design, 14 anaerobically trained male hockey players completed six Wingate cycling tests: familiarization trials of a 30-s and 60-s Wingate test, followed by 30-s Wingate placebo/beet juice trials, and 60-s Wingate placebo/beet juice trials. Repeated measures ANOVAs were used to compare the change in power between conditions over the duration of each trial. Paired t-tests were run to compare performance between conditions of various work and power variables. One-way ANOVAs were utilized to compare the change between conditions of the 30-s test to the change between conditions of the 60-s test. Beet juice supplementation yielded no statistical differences from placebo in any of the measured variables during the 30-s or 60-s tests (p > 0.05). The percent change for fatigue index was significantly different between the 30-s and 60-s tests (p = 0.032) suggesting less fatigue with beet juice supplementation. Overall, beet juice did not improve maximal intensity performance during 30-s or 60-s cycling sprint tests. Performance during the 60-s bout was not impacted to a greater extent than the 30-s bout after beet juice supplementation. These results suggest that beet juice supplementation does not improve short-duration exercise performance in anaerobically trained athletes.
... Three studies have implemented a nitrate loading protocol before a dynamic session of resistance exercise (39,78). Mosher et al. (87) required resistance-trained males to complete 3 sets of bench press to failure at 60% 1RM after 6 days of supplementation with 6.4 mmol of BRJ (400 mg nitrate) or placebo in a crossover fashion. Interestingly, the BRJ treatment completed more repetitions per set and greater total repetitions compared to placebo with no observed differences for lactate concentrations or subjective fatigue. ...
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Several dietary supplements have been proposed as a means of improving muscle strength and hypertrophy when combined with resistance training. However, few have received sufficient attention from sports scientists to produce robust evidence for being well recommended. A growing body of literature has emerged for several dietary ingredients with the potential to promote muscular adaptations. Therefore, the aim of this review is to provide an evidence-based review of the efficacy of emerging nutritional supplements to allow athletes, coaches, and practitioners to make an informed decision when considering their use as a means of improving muscle strength and hypertrophy.
... www.nature.com/scientificreports/ Chronic NO 3 − intake has demonstrated to be a suitable nutritional strategy to enhance resistance exercise performance in terms of total weight lifted, and repetitions until failure at 60% of 1RM 40 . NO 3 − in the potassium NO 3 − salt form did not improve specific performance during CrossFit workouts (Grace protocol) with a mixture of aerobic-anaerobic demand and muscular exhaustion 41 . ...
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This study aimed to determine the effects of circulating nitrate plus nitrite (NOx) concentrations on resistance exercise performance, VO2 and biomarkers of muscle damage. Eleven well-trained male CrossFit athletes (29.2 ± 3.7 years, 78.9 ± 5.4 kg, 175.1 ± 6.3 cm) carried out a resistance exercise test after drinking 140 mL of beetroot juice (BJ) or placebo. The test consisted of repeating the same resistance exercise routine twice: wall ball shots plus full back squat with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. Higher NOx plasma levels were verified after BJ than placebo in the pretest and post-test (p < 0.001). A higher number of repetitions was observed after BJ intake compared to placebo in the full back squat exercise during the first routine (p = 0.004). A significantly reduced VO2 was detected after BJ intake compared to placebo during rest and full back squat execution in the first routine (p < 0.05). Plasma myoglobin concentrations were significantly increased with BJ compared to placebo (p = 0.036). These results showed that plasma NOx levels reduced VO2 after BJ intake during rest time. These reduced VO2 was a key factor for improving full back squat performance during the first routine.
... Dietary NO3supplementation may have beneficial effects on explosive, power-dependent pursuits like sprinting 45 or weight-lifting. 46 Research again from high-quality, placebo-controlled, and double-blind NO3supplementation interventions, indicates maximal power during single-leg knee extension, cycling, and running exercise improves with dietary NO3supplementation administered either acutely within 2-3 hours of exercise [47][48][49][50][51][52] or chronically for 5-6 d in men and women with varied training histories. 45,53 While the exact mechanisms accounting for gains in maximal power production are largely unknown, alterations in calcium availability and/or sensitivity in the contracting muscle fibers may be responsible. ...
Article
Over the last decade, there has been a growing interest in the utility of nitrate (NO3 −) supplementation to improve exercise-related performance. After consumption, dietary NO3 − can be reduced to nitric oxide, a free radical gas involved in numerous physiological actions including blood vessel vasodilation, mitochondrial respiration, and skeletal muscle contractile function. Emerging evidence indicates that dietary NO3 − supplementation has a small but nevertheless significant beneficial effect on endurance performance through the combined effects of enhanced tissue oxygenation and metabolic efficiency in active skeletal muscle. There is further evidence to suggest that dietary NO3 − exerts a direct influence on contractile mechanisms within the skeletal muscle through alterations in calcium availability and sensitivity. Response heterogeneity and sizeable variability in the nitrate content of beetroot juice products influence the effectiveness of dietary NO3 − for exercise performance, and so dosing and product quality, as well as training history, sex, and individual-specific characteristics, should be considered.
... The use of beetroot juice has been investigated in the management of hypertension [109,110], for the improvement of physical performance [111,112], and also in post-exercise recovery [113]. It has been found that acute supplementation of beetroot juice (250 mL) ×3 servings, two serving 24 h and 48 h following completion of 100-drop jumps attenuated muscle soreness and decrements in countermovement jump performance induced by eccentric exercise, while apparently having no effect on maximal isometric voluntary contractions, CK and some inflammatory markers (IL-6, TNF-alpha and IL-8) [114]. ...
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Post-exercise recovery is a broad term that refers to the restoration of training capacity. After training or competition, there is fatigue accumulation and a reduction in sports performance. In the hours and days following training, the body recovers and performance is expected to return to normal or improve. ScienceDirect, PubMed/MEDLINE, and Google Scholar databases were reviewed to identify studies and position declarations examining the relationship between nutrition and sports recovery. As an evidence-based framework, a 4R’s approach to optimizing post-exercise recovery was identified: (i) Rehydration—a fundamental process that will depend on the athlete, environment and sports event; (ii) Refuel—the consumption of carbohydrates is not only important to replenish the glycogen reserves but also to contribute to the energy requirements for the immune system and tissue reparation. Several bioengineered carbohydrates were discussed but further research is needed; (iii) Repair—post-exercise ingestion of high-quality protein and creatine monohydrate benefit the tissue growth and repair; and (iv) Rest—pre-sleep nutrition has a restorative effect that facilitates the recovery of the musculoskeletal, endocrine, immune, and nervous systems. Nutritional consultancy based on the 4R’s is important for the wise stewardship of the hydration, feeding, and supplementation strategies to achieve a timely recovery.
... Although inorganic nitrate itself is relatively inert, metabolic pathways have been identified in humans that convert this compound into bioactive nitrite and nitric oxide (NO), which have the potential to elicit a wide range of physiological effects [3,4]. Research from several independent groups has shown that both acute and chronic consumption of inorganic nitrate, which increases NO bioavailability, can improve performance across various time-trial [5][6][7][8][9], time-to-exhaustion [10,11], high-intensity intermittent [12,13] and strengthbased [14,15] exercise tasks, as well as exercise tolerance in certain clinical populations [16]. However, dietary nitrate ingestion does not enhance exercise performance under all conditions (e.g. ...
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Introduction Dietary inorganic nitrate is a popular nutritional supplement, which increases nitric oxide bioavailability and may improve exercise performance. Despite over a decade of research into the effects of dietary nitrate supplementation during exercise there is currently no expert consensus on how, when and for whom this compound could be recommended as an ergogenic aid. Moreover, there is no consensus on the safe administration of dietary nitrate as an ergogenic aid. This study aimed to address these research gaps. Methods The modified Delphi technique was used to establish the views of 12 expert panel members on the use of dietary nitrate as an ergogenic aid. Over three iterative rounds (two via questionnaire and one via videoconferencing), the expert panel members voted on 222 statements relating to dietary nitrate as an ergogenic aid. Consensus was reached when > 80% of the panel provided the same answer (i.e. yes or no). Statements for which > 80% of the panel cast a vote of insufficient evidence were categorised as such and removed from further voting. These statements were subsequently used to identify directions for future research. Results The 12 panel members contributed to voting in all three rounds. A total of 39 statements (17.6%) reached consensus across the three rounds (20 yes, 19 no). In round one, 21 statements reached consensus (11 yes, 10 no). In round two, seven further statements reached consensus (4 yes, 3 no). In round three, an additional 11 statements reached consensus (5 yes, 6 no). The panel agreed that there was insufficient evidence for 134 (60.4%) of the statements, and were unable to agree on the outcome of the remaining statements. Conclusions This study provides information on the current expert consensus on dietary nitrate, which may be of value to athletes, coaches, practitioners and researchers. The effects of dietary nitrate appear to be diminished in individuals with a higher aerobic fitness (peak oxygen consumption [V̇O2peak] > 60 ml/kg/min), and therefore, aerobic fitness should be taken into account when considering use of dietary nitrate as an ergogenic aid. It is recommended that athletes looking to benefit from dietary nitrate supplementation should consume 8–16 mmol nitrate acutely or 4–16 mmol/day nitrate chronically (with the final dose ingested 2–4 h pre-exercise) to maximise ergogenic effects, taking into consideration that, from a safety perspective, athletes may be best advised to increase their intake of nitrate via vegetables and vegetable juices. Acute nitrate supplementation up to ~ 16 mmol is believed to be safe, although the safety of chronic nitrate supplementation requires further investigation. The expert panel agreed that there was insufficient evidence for most of the appraised statements, highlighting the need for future research in this area. Graphical Abstract
... BR supplements have received less attention in resistance training (28) ( Table 2). In this case, we can refer to the research of Mosher et al. who stated that taking BR supplement for 6 days increases muscle endurance and number of repetitions (32). Moreover, recent studies have shown that BR preferentially enhance blood flow (58) and muscle contraction (59) in the type II muscle fibers, but has no effect on the type 1 fibers. ...
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Athletes often seek to use dietary supplements to increase performance during exercise. Among various supplements, much attention has been paid to beetroot in recent years. Beetroot is a source of carbohydrates, fiber, protein, minerals, and vitamins; also, it is a natural source of nitrate and associated with improved sports performance. Nitrates can the modification of skeletal muscle contractile proteins or calcium handling after translation. The time to reach the peak plasma nitrate is between 1 and 3 h after consumption of a single dose of nitrate. Nitrate is metabolized by conversion to nitrite and subsequently nitric oxide. Beetroot can have various effects on athletic performance through nitric oxide. Nitric oxide is an intracellular and extracellular messenger for regulating certain cellular functions and causes vasodilation of blood vessels and increases blood flow. Nitric oxide seems to be effective in improving athletic performance by increasing oxygen, glucose, and other nutrients for better muscle fueling. Nitric oxide plays the main role in anabolic hormones, modulates the release of several neurotransmitters and the major mediators of stress involved in the acute hypothalamic-pituitary-adrenal response to exercise. Beetroot is an important source of compounds such as ascorbic acid, carotenoids, phenolic acids, flavonoids, betaline, and highly active phenolics and has high antioxidant properties. Beetroot supplement provides an important source of dietary polyphenols and due to the many health benefits. Phytochemicals of Beetroot through signaling pathways inhibit inflammatory diseases. In this study, the mechanisms responsible for these effects were examined and the research in this regard was reviewed.
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Öz: Son yıllarda aktif kaslara oksijen taşınmasını artırmaya yönelik beslenme uygulamalarından yüksek nitrat içeriği dolayısı ile kırmızı pancar suyu ön plana çıkarak spor beslenmesinde popülerliğini arttırmaya başlamıştır. Literatürdeki çalışmalar kırmızı pancar suyu tüketiminin çeşitli spor dallarında performansı arttırdığını ve genel toplum sağlığını iyileştirmeye yönelik de faydalarının olabileceğini göstermektedir. Bu çalışmanın amacı kırmızı pancar suyu tüketiminin sportif performans ve sağlığın iyileştirilmesi üzerine etkilerini ortaya koymak ve olası etki mekanizmalarını açıklamaktır. Abstract: In recent years, beetroot juice has started to increase its popularity in sports nutrition due to its high nitrate content from nutrition applications to increase the oxygen transport to active muscles. Several studies in the literature show that beetroot juice consumption improves performance in various sport branches and may have benefits to improve general public health. The aim of this study is to demonstrate the effectiveness of beetroot consumption on athletic performance and to explain possible mechanisms of action.
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O óxido nítrico possui papel importante na regulação de parâmetros funcionais e fisiológicos relacionados ao desempenho esportivo. Recentemente, foi comprovada sua ação vasodilatadora e hipotensiva, bem como no aumento da eficiência energética e na melhora da contração muscular além de conversão de fibras musculares. Sua principal via de formação é dependente das óxido nítrico sintases, enzimas dependentes de oxigênio que, em hipóxia, reduzem sua ação. Nestas situações, o NO é formado a partir do nitrato inorgânico (NO3-) e nitrito provenientes da alimentação. O aumento da ingestão de NO3-, por alimentação ou suplementação, parece promover aumento de desempenho esportivos em diversos tipos de exercício. Entretanto, seu efeito ergogênico é dependente do condicionamento físico, tipo e duração do exercício e da dose administrada. Indivíduos com menor condicionamento físico parecem se beneficiar mais dos efeitos da suplementação que indivíduos treinados. Além disso, a suplementação parece potencializar o desempenho de forma mais consistente frente a exercícios de alta intensidade e curta duração quando comparada com seus efeitos sobre exercícios de endurance.
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Resistance exercise is a widely-used method of physical training in both recreational exercise and athletic populations. The use of training partners and spotters during resistance exercise is widespread, but little is known about the effect of the presence of these individuals on exercise performance. The purpose of the current study was to investigate the effect of spotter presence on bench press performance. Twelve recreationally trained participants (age, 21.3 ± 0.8 yrs, height, 1.82 ± 0.1 m, and weight, 84.8 ± 11.1 kg) performed two trials of three sets to failure at 60% of 1 repetition maximum on separate occasions. The two trials consisted of spotters being explicitly present or hidden from view (deception). During the trials, total repetitions (reps), total weight lifted, ratings of perceived exertion, and self-efficacy were measured. Total reps and weight lifted were significantly greater with spotters (difference = 4.5 reps, t = 5.68, p < 0.001; difference = 209.6 kg, t = 5.65, p < 0.001; respectively). Whilst RPE and Local-RPE were significantly elevated in the deception trials (difference = 0.78, f = 6.16, p = 0.030; difference = 0.81, f = 5.89, p = 0.034 respectively), self-efficacy was significantly reduced (difference = 1.58, f = 26.90, p < 0.001). This study demonstrates that resistance exercise is improved by the presence of spotters, which is facilitated by reduced RPE and increased self-efficacy. This has important implications for athletes and clients, who should perform resistance exercise in the proximity of others, to maximize total work done.
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Background and Objective: Elevated blood pressure may develop in hypertensive patients after performing resistance training. The present study aimed to investigate the effect of beetroot juice on cardiovascular and functional changes during and after a session of acute resistance training in men with hypertension. Materials and Methods: In the present single-blind quasi-experimental study, 20 men with hypertension were randomly divided into two groups of Beetroot Juice (BJ) and Placebo (PLA). Upper and lower body muscular strength, Perceived Exertion (RPE), Systolic and Diastolic blood pressure (SBP, DBP), and resting and continuous Heart Rate (HR) were measured after resistance training in the pre-test. In the post-test, BJ and PLA groups consumed beetroot juice and non-caloric cherry flavor Beverage (4.5 mg/Kg Bodyweight), respectively, 150 minutes before repeating the measurements. Data were analyzed using three-way ANOVA, student’s t-test, and Mann–Whitney U test at a significance level of 0.05. Results: Beetroot juice significantly reduced SBP, DBP, and HR at rest and after resistance training compared to PLA. Furthermore, BJ significantly increased lower body muscular strength and decreased RPE during resistance training. Conclusion: Beetroot juice is a useful beverage that easily and harmlessly controls blood pressure in hypertensive patients. This drink prevents the risk of high blood pressure in addition to improving performance during resistance training.
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Purpose Several supplements are purported to promote muscle hypertrophy and strength gains in healthy subjects, or to prevent muscle wasting in atrophying situations (e.g., ageing or disuse periods). However, their effectiveness remains unclear. Methods This review summarizes the available evidence on the beneficial impacts of several popular supplements on muscle mass or strength. Results Among the supplements tested, nitrate and caffeine returned sufficient evidence supporting their acute beneficial effects on muscle strength, whereas the long-term consumption of creatine, protein and polyunsaturated fatty acids seems to consistently increase or preserve muscle mass and strength (evidence level A). On the other hand, mixed or unclear evidence was found for several popular supplements including branched-chain amino acids, adenosine triphosphate, citrulline, β-Hydroxy-β-methylbutyrate, minerals, most vitamins, phosphatidic acid or arginine (evidence level B), weak or scarce evidence was found for conjugated linoleic acid, glutamine, resveratrol, tribulus terrestris or ursolic acid (evidence level C), and no evidence was found for other supplements such as ornithine or α-ketoglutarate (evidence D). Of note, although most supplements appear to be safe when consumed at typical doses, some adverse events have been reported for some of them (e.g., caffeine, vitamins, α-ketoglutarate, tribulus terrestris, arginine) after large intakes, and there is insufficient evidence to determine the safety of many frequently used supplements (e.g., ornithine, conjugated linoleic acid, ursolic acid). Conclusion In summary, despite their popularity, there is little evidence supporting the use of most supplements, and some of them have been even proven ineffective or potentially associated with adverse effects.
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Background Dietary inorganic nitrate (NO 3 ⁻ ) is a polyatomic ion, which is present in large quantities in green leafy vegetables and beetroot, and has attracted considerable attention in recent years as a potential health-promoting dietary compound. Numerous small, well-controlled laboratory studies have reported beneficial health effects of inorganic NO 3 ⁻ consumption on blood pressure, endothelial function, cerebrovascular blood flow, cognitive function, and exercise performance. Translating the findings from small laboratory studies into ‘real-world’ applications requires careful consideration. Main body This article provides a brief overview of the existing empirical evidence basis for the purported health-promoting effects of dietary NO 3 ⁻ consumption. Key areas for future research are then proposed to evaluate whether promising findings observed in small animal and human laboratory studies can effectively translate into clinically relevant improvements in population health. These proposals include: 1) conducting large-scale, longer duration trials with hard clinical endpoints (e.g. cardiovascular disease incidence); 2) exploring the feasibility and acceptability of different strategies to facilitate a prolonged increase in dietary NO 3 ⁻ intake; 3) exploitation of existing cohort studies to explore associations between NO 3 ⁻ intake and health outcomes, a research approach allowing larger samples sizes and longer duration follow up than is feasible in randomised controlled trials; 4) identifying factors which might account for individual differences in the response to inorganic NO 3 ⁻ (e.g. sex, genetics, habitual diet) and could assist with targeted/personalised nutritional interventions; 5) exploring the influence of oral health and medication on the therapeutic potential of NO 3 ⁻ supplementation; and 6) examining potential risk of adverse events with long term high- NO 3 ⁻ diets. Conclusion The salutary effects of dietary NO 3 ⁻ are well established in small, well-controlled laboratory studies. Much less is known about the feasibility and efficacy of long-term dietary NO 3 ⁻ enrichment for promoting health, and the factors which might explain the variable responsiveness to dietary NO 3 ⁻ supplementation between individuals. Future research focussing on the translation of laboratory data will provide valuable insight into the potential applications of dietary NO 3 ⁻ supplementation to improve population health.
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Although over 100 studies and reviews have examined the ergogenic effects of dietary nitrate (NO3) supplementation in young, healthy men and women, it is unclear if participant and environmental factors modulate the well-described ergogenic effects-particularly relevant factors include biological sex, aerobic fitness, and fraction of inspired oxygen (FiO2) during exercise. To address this limitation, the literature was systematically reviewed for randomized, crossover, placebo-controlled studies reporting exercise performance outcome metrics with NO3 supplementation in young, healthy adults. Of the 2033 articles identified, 80 were eligible for inclusion in the meta-analysis. Random-effects meta-analysis demonstrated that exercise performance improved with NO3 supplementation compared with placebo (d = 0.174; 95% confidence interval (CI), 0.120-0.229; P < 0.001). Subgroup analyses conducted on biological sex, aerobic fitness, and FiO2 demonstrated that the ergogenic effect of NO3 supplementation was as follows: 1) not observed in studies with only women (n = 6; d = 0.116; 95% CI, -0.126 to 0.358; P = 0.347), 2) not observed in well-trained endurance athletes (≥65 mL·kg·min; n = 26; d = 0.021; 95% CI, -0.103 to 0.144; P = 0.745), and 3) not modulated by FiO2 (hypoxia vs normoxia). Together, the meta-analyses demonstrated a clear ergogenic effect of NO3 supplementation in recreationally active, young, healthy men across different exercise paradigms and NO3 supplementation parameters; however, the effect size of NO3 supplementation was objectively small (d = 0.174). NO3 supplementation has more limited utility as an ergogenic aid in participants with excellent aerobic fitness that have optimized other training parameters. Mechanistic research and studies incorporating a wide variety of subjects (e.g., women) are needed to advance the study of NO3 supplementation; however, additional descriptive studies of young, healthy men may have limited utility.
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Dietary nitrate consumption from foods such as beetroot has been associated with many physiological benefits including improvements in vascular health and exercise performance. More recently, attention has been given to the use of dietary nitrate as a nutritional strategy to optimize muscular performance during resistance exercise. Our purpose was to perform a systematic review and meta-analysis of the research literature assessing the effect of dietary nitrate ingestion on muscular strength and muscular endurance. A structured search was carried out in accordance with PRISMA guidelines and from the total included studies (n = 34 studies), 12 studies had data for both measurements of strength and muscular endurance outcomes, 14 studies had data only for muscular strength outcome, and 8 studies had data only for muscular endurance outcome. Standardized mean difference (SMD) was calculated and meta-analyses were performed by using a random-effects model. Dietary nitrate ingestion was found to result in a trivial but significant effect on muscular strength (overall SMD = 0.08, P = 0.0240). Regarding muscular endurance dietary nitrate was found to promote a small but significant effect (overall SMD = 0.31, P < 0.0001). Dosage, frequency of ingestion, training level, muscle group, or type of contraction did not affect the findings, except for a greater improvement in muscle endurance during isometric and isotonic when compared to isokinetic contractions. Dietary nitrate seems to have a positive effect on muscular strength and muscular endurance, which is mostly unaffected by dosage, frequency of ingestion, training level, muscle group, or type of contraction. However, given the trivial to small effect, further experimental research on this topic is warranted.
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Introduction:Tennis is characterized by a large number of competitions and little recovery time between them. Thus, tennis players and coaching staff have become interested in the role that nutrition can play in maximizing sports performance. The scientific literature does not have recent narrative and/or systematic reviews about to nutrition in tennis. The aim of this study is to map, describe and discuss the state of the science of nutrition and dietetic practices for tennis players from a theoretical and contextual point of view, to enable focused future systematic reviews. Material and methods: A narrative review through the Dialnet, Elsevier, Medline, Pubmed and Web of Science databases, through a search strategy based on keywords separated by Boolean connectors. A series of inclusion / exclusion criteria were applied to select those investigations that responded to the aim of the work. Results: Nutritional recommendations on carbohydrate intake depend on the training load, 5-7 g/kg/day g/kg/day for normal training and 7-10 g/kg/day for competitive periods or high training load. The recommended protein intake is 1.8 g/kg/day and 1 g/kg/day of lipids. The supplements that can optimize tennis performance are caffeine, sodium bicarbonate, creatine and -alanine. Beetroot juice can be a possible aid to consider in dietetic-nutritional planning in tennis players. Conclusions: Performance and health of tennis player can be optimized, as well as adequate periodization of nutrients and supplements, meeting to the physiological demands of tennis.
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Gonzalez, AM and Trexler, ET. Effects of citrulline supplementation on exercise performance in humans: A review of the current literature. J Strength Cond Res XX(X): 000-000, 2020-L-citrulline, a nonessential amino acid found primarily in watermelon, has recently garnered much attention for its potential to augment L-arginine bioavailability, nitric oxide production, and exercise performance. Over the past decade, L-citrulline has received considerable scientific attention examining potentially ergogenic properties for both aerobic and anaerobic exercise performance. Thus, the purpose of this article is to summarize the theoretical rationale behind L-citrulline supplementation and to comprehensively review the available scientific evidence assessing the potential ergogenic value of L-citrulline supplementation on vascular function and exercise performance in humans. In addition, research that has investigated the potential synergistic effects of L-citrulline with other dietary ingredients (e.g., arginine, antioxidants, nitrates, and branched-chain amino acids) is reviewed. Oral L-citrulline and citrulline malate supplementation have shown to increase plasma citrulline and arginine concentrations, along with total nitrate and nitrite concentrations. Although blood flow enhancement is a proposed mechanism for the ergogenic potential of L-citrulline, evidence supporting acute improvements in vasodilation and skeletal muscle tissue perfusion after supplementation is scarce and inconsistent. Nevertheless, several studies have reported that L-citrulline supplementation can enhance exercise performance and recovery. Given the positive effects observed from some investigations, future studies should continue to investigate the effects of both acute and chronic supplementation with L-citrulline and citrulline malate on markers of blood flow and exercise performance and should seek to elucidate the mechanism underlying such effects.
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Dietary nitrates (DN) are scientifically proven ergogenic substances. Their benefits are described in physical performance of medium to maximum intensity lasting 6-30 minutes. The increased availability of DN supports the production of nitric oxide (NO) and, therefore, muscle work, which can positively affect exercise economy and physical per-formance. Improvement is more often seen after long-term use with a higher degree of effectiveness in a less-trained population. We carried out a double-blind cross-over placebo-controlled study focusing on the effects of acute and chronic beetroot juice concentrate intake (400-800 mg of DN per dose) on endurance performance in 19 young men (10 recreationally trained and 9 trained). On the 1., 7. and 8. day of DN use, the group underwent physical testing, blood sampling and additional measurements. We observed increased NO availability via increased plasma nitrate values (p < 0.05). However, blood pressure (BP), oxygen consumption during the tests, exercise tolerance, RPE and biochemical response remained unchanged despite the high availability of NO (p > 0.05). Group’s VO2max over 45 ml/kg/min, which according to current knowledge, may have limited the ergogenic effect of DN. Future re-search should focus on even less-trained or weakened populations, where DN can serve as a nutritional training aid or a treatment aid. It can also be used in other sports disciplines requiring a higher involve-ment of type II muscle fibres.
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