CoChat
Sign Up
Cited by 36Muscle metabolism and nutritionSports Performance and TrainingExercise and Physiological Responses

Effects of Dietary Nitrate Supplementation on Weightlifting Exercise Performance in Healthy Adults: A Systematic Review

Open access
San Juan, Alejandro F., Dominguez, Raul, Lago-Rodríguez, Ángel, Montoya, Juan José, Tan, Rachel, Bailey, Stephen J.·2020·Nutrients
DOI 10.3390/nu12082227PMC PMC7469052
Open this paper in CoChat — free accountOpen PDF

Abstract

Dietary nitrate (NO3−) 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 NO3− 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 NO3− 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 NO3− 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 NO3− 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 NO3− supplementation on weightlifting exercise performance to be determined.

AI snapshot

Written from the paper’s full text.

TL;DR

This systematic review of four studies (49 resistance-trained men) found preliminary evidence that dietary nitrate supplementation may improve some weightlifting performance outcomes, particularly bench press power, velocity, and repetitions to failure, but not consistently box squat performance. The authors conclude further research is needed because of limited high-quality evidence and heterogeneous dosing and exercise protocols.

Key findings

  • Four studies met the inclusion criteria. Two reported upper-body benefits: acute beetroot juice increased mean power by 19.5%, mean velocity by 6.5%, and repetitions to failure by 10.7% during free-weight bench press at 70% 1RM; 6 days of beetroot juice increased repetitions to failure by 19.4% and total weight lifted by 18.9% during Smith machine bench press at 60% 1RM.
  • One study observed a 17.7% increase in repetitions to failure summed across bench press and back squat at 60%, 70%, and 80% 1RM after acute beetroot juice, but no effect on muscular velocity or power. Another study found no change in repetitions to failure during box squat at 60% 1RM after low-dose nitrate-rich bars.
  • Overall, acute and short-term nitrate supplementation may enhance bench press performance in resistance-trained males, but effects on lower-body squat performance are inconsistent. Proposed mechanisms include enhanced skeletal muscle excitation–contraction coupling, improved metabolic control, and increased muscle perfusion.

Methods

  • PRISMA-guided systematic search of Dialnet, Directory of Open Access Journals, Medline, PubMed, Scielo, Scopus, and SPORTDiscus until April 2020, using nitrate/beetroot, supplement/nutrition/diet, and strength/resistance exercise/training/muscular power terms. The original search yielded 619 studies; 291 were independently reviewed; 4 met eligibility. Quality was assessed with the PEDro scale.
  • Inclusion criteria required full articles in healthy humans aged 18–65 years, a nitrate and placebo intervention, voluntary dynamic resistance exercise (not isometric, isokinetic, or NMES-evoked), and outcomes including 1RM, power or movement velocity, or repetitions to failure with submaximal loads. The four included studies comprised 49 men, all resistance trained.
  • Supplementation protocols varied: two studies used acute 70 mL beetroot juice (~6.4 mmol nitrate) ~2 h before exercise; one used 70 mL/day (~6.4 mmol nitrate) for 6 days; one used two nitrate-rich performance bars (32.5 mg nitrate per two bars) for 3 days, with the final bars ~60 min before exercise. The review presents a narrative synthesis.

Limitations

  • The paper states that the number of high-quality randomized controlled trials focused on weightlifting exercise is limited, restricting the analyzed sample; between-study differences in nitrate dose (from 32.5 mg to 6.4 mmol), supplementation period (acute to 6 days), and exercise type prevented a firm conclusion. It also notes that all existing studies lacked plasma nitrite determination.
  • Evident from the text: all included participants were men and resistance trained, so findings may not generalize to women, untrained individuals, older adults, or other populations. Only four studies were included and no meta-analysis was performed, so the performance estimates are preliminary.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3390/nu12082227

Cites

155 of 155 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 149 cited sources checked · 0 supported · 0 flagged

  • Findingcitation

    Ranchal-Sánchez et al. observed an enhancement in the number of repetitions to failure (+17.7%) in the sum of sets for bench press and back squat with loads of 60%, 70% and 80% 1RM after NO3− supplementation.

    “In another study, Ranchal-Sánchez et al. [114] observed an enhancement in the number of repetitions to failure (+17.7%) in the sum of sets for bench press and back squat with loads of 60%, 70% and 80% 1RM after NO3− supplementation (BR ingested 2 h prior to exercise), although authors failed to find an effect on muscular velocity and power.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [114] Ranchal-Sanchez, A., Diaz-Bernier, V.M., De La Florida-Villagran, C.A., Llorente-Cantarero, F.J., Campos-Perez, J., and Jurado-Castro, J.M. (2020). Acute Effects of Beetroot Juice Supplements on Resistance Training: A Randomized Double-Blind Crossover. Nutrients, 12. source

      Not checked in the free run.

  • Findingcitation

    Ranchal-Sánchez et al. failed to find an effect on muscular velocity and power after NO3− supplementation.

    “In another study, Ranchal-Sánchez et al. [114] observed an enhancement in the number of repetitions to failure (+17.7%) in the sum of sets for bench press and back squat with loads of 60%, 70% and 80% 1RM after NO3− supplementation (BR ingested 2 h prior to exercise), although authors failed to find an effect on muscular velocity and power.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [114] Ranchal-Sanchez, A., Diaz-Bernier, V.M., De La Florida-Villagran, C.A., Llorente-Cantarero, F.J., Campos-Perez, J., and Jurado-Castro, J.M. (2020). Acute Effects of Beetroot Juice Supplements on Resistance Training: A Randomized Double-Blind Crossover. Nutrients, 12. source

      Not checked in the free run.

  • Findingcitation

    Williams et al. observed a 10.7% increase in the number of repetitions to failure during free-weight bench press exercise at 70%1RM in resistance-trained men after acute dietary NO3− supplementation.

    “The authors observed a 19.5% increase in mean power, a 6.5% increase in mean velocity, and a 10.7% increase in the number of repetitions to failure [113].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [113] Williams, 2020, Effect of Acute Beetroot Juice Supplementation on Bench Press Power, Velocity, and Repetition Volume, J. Strength Cond. Res. source

      Not checked in the free run.

  • Findingnone given

    A limited number of studies have assessed the potential for ergogenic effects of NO3− supplementation on a more transferable form of resistance exercise, such as weightlifting performance.

    “Despite the evidence outlined above, which suggests that NO3− supplementation has the potential to enhance resistance exercise performance during voluntary isometric and/or isokinetic assessments, and muscle isometric contractions evoked by NMES, a limited number of studies have assessed the potential for ergogenic effects of NO3− supplementation on a more transferable form of resistance exercise,”
    Quote in the paperSubstantial claim
  • Findingcitation

    Williams et al. observed a 19.5% increase in mean power during free-weight bench press exercise at 70%1RM in resistance-trained men after acute dietary NO3− supplementation.

    “The authors observed a 19.5% increase in mean power, a 6.5% increase in mean velocity, and a 10.7% increase in the number of repetitions to failure [113].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [113] Williams, 2020, Effect of Acute Beetroot Juice Supplementation on Bench Press Power, Velocity, and Repetition Volume, J. Strength Cond. Res. source

      Not checked in the free run.

  • Classified as probably not a substantial claim. 17
  • May combine two claims. 36

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingcitation

    The exercise modalities used to assess weightlifting exercise performance were bench press using free weights, bench press using a Smith machine, and box squats using a Smith machine.

    “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].”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [113] Williams, 2020, Effect of Acute Beetroot Juice Supplementation on Bench Press Power, Velocity, and Repetition Volume, J. Strength Cond. Res. source

      Not checked in the free run.

    • cites [114] Ranchal-Sanchez, A., Diaz-Bernier, V.M., De La Florida-Villagran, C.A., Llorente-Cantarero, F.J., Campos-Perez, J., and Jurado-Castro, J.M. (2020). Acute Effects of Beetroot Juice Supplements on Resistance Training: A Randomized Double-Blind Crossover. Nutrients, 12. source

      Not checked in the free run.

    • cites [116] Mosher, 2016, Ingestion of a Nitric Oxide Enhancing Supplement Improves Resistance Exercise Performance, J. Strength Cond. Res. source

      Not checked in the free run.

    • cites [115] Flanagan, 2016, The Effects of Nitrate-Rich Supplementation on Neuromuscular Efficiency during Heavy Resistance Exercise, J. Am. Coll. Nutr. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Findingown data

    A total of four articles met the eligibility criteria for the present systematic review.

    “A total of four articles met the eligibility criteria for the present systematic review (Figure 1).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The original search yielded a total of 619 studies.

    “The original search yielded a total of 619 studies.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The four studies selected included a total of 49 men, all of whom were resistance trained (performed resistance exercise a minimum of twice per week).

    “The four studies selected for our systematic review included a total of 49 men, all of whom were resistance trained (i.e., performed resistance exercise a minimum of twice per week).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    Williams et al. assessed muscle power and velocity during two single explosive repetitions with full recovery (5 min rest between sets), whereas Ranchal-Sánchez et al. assessed power and velocity during sets of repetitions until failure.

    “Indeed, whereas Williams et al. [113] assessed muscle power and velocity during two single explosive repetitions with full recovery (5 min rest between sets), Ranchal-Sánchez et al. [114] assessed power and velocity during sets of repetitions until failure.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [113] Williams, 2020, Effect of Acute Beetroot Juice Supplementation on Bench Press Power, Velocity, and Repetition Volume, J. Strength Cond. Res. source

      Not checked in the free run.

    • cites [114] Ranchal-Sanchez, A., Diaz-Bernier, V.M., De La Florida-Villagran, C.A., Llorente-Cantarero, F.J., Campos-Perez, J., and Jurado-Castro, J.M. (2020). Acute Effects of Beetroot Juice Supplements on Resistance Training: A Randomized Double-Blind Crossover. Nutrients, 12. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given

    This is the first systematic review to have focused on the ergogenic effect of dietary NO3− supplementation on weightlifting exercise performance.

    “This is the first systematic review to have focused on the ergogenic effect of dietary NO3− supplementation on weightlifting exercise performance.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    Flanagan et al. administered 32.5 mg (~0.5 mmol) of NO3− daily, which is markedly lower than Williams et al. (6.4 mmol NO3− acutely) and Mosher et al. (6 days of 6.4 mmol NO3− daily).

    “Specifically, Flanagan et al. [115] administered 32.5 mg (~0.5 mmol) of NO3− daily, which is markedly lower than Williams et al. [113] (6.4 mmol NO3− acutely) and Mosher et al. [116] (6 days of 6.4 mmol NO3− daily), both of whom observed improved resistance exercise performance.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [115] Flanagan, 2016, The Effects of Nitrate-Rich Supplementation on Neuromuscular Efficiency during Heavy Resistance Exercise, J. Am. Coll. Nutr. source

      Not checked in the free run.

    • cites [113] Williams, 2020, Effect of Acute Beetroot Juice Supplementation on Bench Press Power, Velocity, and Repetition Volume, J. Strength Cond. Res. source

      Not checked in the free run.

    • cites [116] Mosher, 2016, Ingestion of a Nitric Oxide Enhancing Supplement Improves Resistance Exercise Performance, J. Strength Cond. Res. source

      Not checked in the free run.

  • May combine two claims.

    Findingcitation

    Whitfield et al. observed increased force production and rate of force production during evoked isometric twitches in healthy humans without changes in skeletal muscle CASQ, DHPR or SERCA protein content following 7 days of BR supplementation.

    “Specifically, these authors observed an increased force production and rate of force production during evoked isometric twitches in healthy humans without changes in skeletal muscle CASQ, DHPR or SERCA protein content following 7 days of BR supplementation.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [96] Whitfield, 2017, Beetroot Juice Increases Human Muscle Force without Changing Ca2+-Handling Proteins, Med. Sci. Sports Exerc. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingcitation

    An interesting observation by Flanagan et al. was that EMG amplitude increased during weightlifting exercise after NO3− supplementation despite no change in weightlifting exercise performance.

    “An interesting observation by Flanagan et al. [115] was that EMG amplitude increased during weightlifting exercise after NO3− supplementation despite no change in weightlifting exercise performance.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [115] Flanagan, 2016, The Effects of Nitrate-Rich Supplementation on Neuromuscular Efficiency during Heavy Resistance Exercise, J. Am. Coll. Nutr. source

      Not checked in the free run.

  • May combine two claims.

    Findingnone given

    The number of high-quality studies (randomized controlled trials) focused on weightlifting exercise is limited, which restricted the sample analyzed in the present systematic review.

    “Although there are numerous studies analyzing the effect of NO3− on various aspects of exercise performance, the number of high-quality studies (i.e., randomized controlled trials) focused on weightlifting exercise is limited, which restricted the sample analyzed in the present systematic review.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Inorganic nitrate ingestion, often administered as concentrated NO3−-rich beetroot juice, has been reported to confer ergogenic effects in various exercise modalities including running, rowing, kayaking, knee extensions and cycling.

    “More recently, inorganic nitrate (NO3−) ingestion, often administered as concentrated NO3−-rich beetroot juice (BR), has been reported to confer ergogenic effects in various exercise modalities [35], including running [36,37,38,39,40,41,42,43,44,45,46,47], rowing [48,49], kayaking [50], knee extensions [37,51] and cycling [52,53,54,55,56,57,58,59,60,61,62,63,64].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [35] Jones, 2018, Dietary nitrate and physical performance, Annu. Rev. Nutr. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Recent systematic reviews support NO3− supplementation efficacy as an ergogenic aid during continuous endurance-type exercise and high-intensity intermittent-type exercise.

    “Although an ergogenic effect of NO3− supplementation appears less likely in endurance-trained individuals, i.e., [65,66,67,68,69,70,71,72,73,74], recent systematic reviews support its efficacy as an ergogenic aid during continuous endurance-type exercise [75,76,77] and high-intensity intermittent-type exercise [78].”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [75] Domínguez, R., Cuenca, E., Maté-Muñoz, J.L., Garca-Fernández, P., Paya, N.S., Lozano-Estevan, M.D.C., Veiga-Herreros, P., and Garnacho-Castaño, M.V. (2017). Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review. Nutrition, 9. source

      Not checked in the free run.

    • cites [76] McMahon, 2016, The Effect of Dietary Nitrate Supplementation on Endurance Exercise Performance in Healthy Adults: A Systematic Review and Meta-Analysis, Sports Med. source

      Not checked in the free run.

    • cites [77] Vukovich, 2018, The Effect of Nitrate Supplementation on Exercise Tolerance and Performance, J. Strength Cond. Res. source

      Not checked in the free run.

    • cites [78] Cuenca, 2018, Effects of beetroot juice supplementation on intermittent high-intensity exercise efforts, J. Int. Soc. Sports Nutr. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Dietary NO3− supplementation elevates nitric oxide bioavailability via reduction of exogenous NO3− to nitrite by commensal anaerobic bacteria in the oral cavity, followed by one-electron reduction of NO2− to NO catalyzed by various NO2− reductases in tissue and blood.

    “Dietary NO3− supplementation has been observed to elevate nitric oxide (NO) bioavailability via the reduction of exogenous NO3− to nitrite (NO2−) by commensal anaerobic bacteria in the oral cavity [79], followed by the one-electron reduction of NO2− to NO (and other nitrogen intermediates) catalyzed by various NO2− reductases [80,81,82,83,84] in the tissue and blood.”
    Quote in the paperSubstantial claim0 of 6 sources checked
    • cites [79] Spiegelhalder, 1976, Influence of dietary nitrate on nitrite content of human saliva: Possible relevance to in vivo formation of N-nitroso compounds, Food Cosmet. Toxicol. source

      Not checked in the free run.

    • cites [80] Cosby, 2003, Nitrite reduction to nitric oxide by deoxyhemoglobin vasodilates the human circulation, Nat. Med. source

      Not checked in the free run.

    • cites [81] Kozlov, 2003, Various intracellular compartments cooperate in the release of nitric oxide from glycerol trinitrate in liver, Br. J. Pharmacol. source

      Not checked in the free run.

    • cites [82] Li, 2008, Nitric Oxide Production from Nitrite Occurs Primarily in Tissues Not in the Blood, J. Biol. Chem. source

      Not checked in the free run.

    • cites [83] Shiva, 2007, Deoxymyoglobin is a nitrite reductase that generates nitric oxide and regulates mitochondrial respiration, Circ. Res. source

      Not checked in the free run.

    • cites [84] Zhang, 1997, Human xanthine oxidase converts nitrite ions into nitric oxide (NO), Biochem. Soc. Trans. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    These improvements in skeletal muscle contractile function were accompanied by increased protein expression of Ca2+-handling proteins in the extensor digitorum longus (predominantly type II fibers) but not the soleus (predominantly type I fibers).

    “These improvements in skeletal muscle contractile function were accompanied by increased protein expression of calcium (Ca2+)-handling proteins in the extensor digitorum longus, which is predominantly comprised of type II muscle fibers, but not the soleus, which is predominantly comprised of type I muscle fibers [98].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [98] Schiffer, 2012, Dietary nitrate increases tetanic [Ca2+]i and contractile force in mouse fast-twitch muscle, J. Physiol. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    NO3− supplementation can enhance force production during voluntary and evoked isometric assessments and isokinetic voluntary knee extensor power and velocity.

    “There is some evidence that NO3− supplementation can enhance force production during voluntary and evoked isometric assessments [73,95,96] and isokinetic voluntary knee extensor power and velocity [97].”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [73] Wickham, 2019, No effect of beetroot juice supplementation on exercise economy and performance in recreationally active females despite increased torque production, Physiol. Rep. source

      Not checked in the free run.

    • cites [95] Haider, 2014, Nitrate Supplementation Enhances the Contractile Properties of Human Skeletal Muscle, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [96] Whitfield, 2017, Beetroot Juice Increases Human Muscle Force without Changing Ca2+-Handling Proteins, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [97] Coggan, 2015, Effect of acute dietary nitrate intake on maximal knee extensor speed and power in healthy men and women, Nitric Oxide source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Collectively, these findings suggest that dietary NO3− supplementation has the potential to increase contractile force production, skeletal muscle power and velocity of contraction, particularly in type II muscle fibers, which are heavily recruited during weightlifting exercise.

    “Collectively, these findings suggest that dietary NO3− supplementation has the potential to increase contractile force production, skeletal muscle power and velocity of contraction, particularly in type II muscle fibers, which are heavily recruited during weightlifting exercise [99].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [99] Morton, 2019, Muscle fibre activation is unaffected by load and repetition duration when resistance exercise is performed to task failure, J. Physiol. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In contrast to rodent studies, there was an increase in evoked contractile force after NO3− supplementation without an effect on muscle Ca2+-handling proteins in human skeletal muscle.

    “However, in contrast to the rodent studies, there was an increase in evoked contractile force after NO3− supplementation without an effect on muscle Ca2+-handling proteins in human skeletal muscle [96].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [96] Whitfield, 2017, Beetroot Juice Increases Human Muscle Force without Changing Ca2+-Handling Proteins, Med. Sci. Sports Exerc. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In rodents, 7 days of NO3− supplementation increased evoked force production at low-stimulation frequencies and rate of force development at high-contraction frequencies compared to age-matched controls.

    “Data from animal studies support these observations and have indicated that 7 days of NO3− supplementation increased evoked force production in rodents at low-stimulation frequencies and the rate of force development at high-contraction frequencies compared to age-matched controls [98].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [98] Schiffer, 2012, Dietary nitrate increases tetanic [Ca2+]i and contractile force in mouse fast-twitch muscle, J. Physiol. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Elevations in [NO3−] and [NO2−] following NO3− supplementation are associated with positive physiological effects that facilitate a greater capacity for muscular work and/or improved muscle contractile efficiency.

    “Elevations in [NO3−] and [NO2−] following NO3− supplementation have been observed in skeletal muscle [88,89,90,91] and plasma [53,64,92], and are associated with positive physiological effects [41,64,74,93] that facilitate a greater capacity for muscular work [51,53,59] and/or improved muscle contractile efficiency (i.e., a lower high-energy phosphate cost of force production) [51,94].”
    Quote in the paperSubstantial claim0 of 8 sources checked
    • cites [41] Porcelli, 2015, Aerobic fitness affects the exercise performance responses to nitrate supplementation, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [64] Wylie, 2013, Beetroot juice and exercise: Pharmacodynamic and dose-response relationships, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [74] Wilkerson, 2012, Influence of acute dietary nitrate supplementation on 50 mile time trial performance in well-trained cyclists, Graefe’s Arch. Clin. Exp. Ophthalmol.

      Not checked in the free run.

    • cites [93] Wendt, 2010, Positive correlation between plasma nitrite and performance during high-intensive exercise but not oxidative stress in healthy men, Nitric Oxide source

      Not checked in the free run.

    • cites [51] Bailey, 2010, Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [53] Bailey, 2009, Dietary nitrate supplementation reduces the O2cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [59] Lansley, 2011, Acute Dietary Nitrate Supplementation Improves Cycling Time Trial Performance, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [94] Fulford, 2013, Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions, Pflüg. Arch. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    NO3− supplementation can lower the PCr cost of muscle force production at the end of a protocol comprising 50 MVIs of the knee extensors and is more effective at improving skeletal muscle contractile function after the muscle has become fatigued.

    “In addition, it has been reported that NO3− supplementation can lower the PCr cost of muscle force production at the end of a protocol comprising 50 MVIs of the knee extensors [94] and is more effective at improving skeletal muscle contractile function after the muscle has become fatigued [103].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [94] Fulford, 2013, Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions, Pflüg. Arch. source

      Not checked in the free run.

    • cites [103] Tillin, 2018, Nitrate supplement benefits contractile forces in fatigued but not unfatigued muscle, Med. Sci. Sports Exerc. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The recovery of muscle force during repeated bouts of high-intensity exercise is linked to muscle PCr resynthesis, which is largely an O2-dependent process.

    “The recovery of muscle force during repeated bouts of high-intensity exercise is linked to muscle PCr resynthesis [104,105,106], which is largely an O2-dependent process [107,108].”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [104] Bogdanis, 1995, Recovery of power output and muscle metabolites following 30 s of maximal sprint cycling in man, J. Physiol. source

      Not checked in the free run.

    • cites [105] Bogdanis, 1996, Contribution of phosphocreatine and aerobic metabolism to energy supply during repeated sprint exercise, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [106] Gaitanos, 1993, Human muscle metabolism during intermittent maximal exercise, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [107] Trump, 1996, Importance of muscle phosphocreatine during intermittent maximal cycling, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [108] Vanhatalo, 2011, Dietary nitrate reduces muscle metabolic perturbation and improves exercise tolerance in hypoxia, J. Physiol. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Motor unit recruitment during NMES is spatially fixed, temporally synchronous and nonselective, such that it may not conform to the orderly recruitment of motor units during voluntary contractions.

    “Specifically. motor unit recruitment during NMES is spatially fixed, temporally synchronous and nonselective (i.e., randomized), such that it may not conform to the orderly recruitment of motor units during voluntary contractions [101].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [101] Henneman, 1957, Relation between Size of Neurons and Their Susceptibility to Discharge, Science source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    A quality assessment procedure was performed by three authors using the PEDro scale.

    “A quality assessment procedure was performed by three authors (ALR, RD and JJM) using the PEDro scale [111].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [111] Maher, 2003, Reliability of the PEDro Scale for Rating Quality of Randomized Controlled Trials, Phys. Ther. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The main findings were that dietary NO3− supplementation can increase muscular power and velocity, and the number of repetitions to failure during bench press exercise, but not box squat exercise, in resistance-trained males.

    “The main findings were that dietary NO3− supplementation can increase muscular power and velocity, and the number of repetitions to failure during bench press exercise, but not box squat exercise, in resistance-trained males.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    After elimination of duplicates and screening, a total of 291 articles were independently read and reviewed by three authors.

    “After the elimination of duplicate articles and screening for inclusion criteria, a total of 291 articles were independently read and reviewed by three authors (RD, JJM and ASF).”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    A systematic search using PRISMA guidelines was conducted for studies investigating NO3− supplementation on weightlifting exercise performance using Dialnet, Directory of Open Access Journals, Medline, Pubmed, Scielo, Scopus and SPORTDiscus databases until April 2020.

    “A systematic search using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines [110] was conducted for studies that investigated NO3− supplementation on weightlifting exercise performance using Dialnet, Directory of Open Access Journals, Medline, Pubmed, Scielo, Scopus and SPORTDiscus databases until April 2020, using the following terms:”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [110] Shamseer, 2015, The PRISMA-P Group Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: Elaboration and explanation, BMJ source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Increased time to task failure following NO3− supplementation was accompanied by lower rates of ATP and PCr turnover, and ADP and Pi accumulation, factors expected to lower skeletal muscle fatigue.

    “This increased time to task failure following NO3− supplementation was accompanied by lower rates of ATP and PCr turnover, and ADP and Pi accumulation, factors that would be expected to lower skeletal muscle fatigue [102].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [102] Allen, 2008, Skeletal Muscle Fatigue: Cellular Mechanisms, Physiol. Rev. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Weightlifting training increases both the hypertrophy and proportion of type II muscle fibers, such that the proportion of type II muscle is greater in resistance-trained individuals.

    “However, there is evidence that weightlifting training increases both the hypertrophy and proportion of type II muscle fibers, such that the proportion of type II muscle is greater in resistance-trained individuals [126,127].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [126] Andersen, 2000, Myosin heavy chain IIX overshoot in human skeletal muscle, Muscle Nerve source

      Not checked in the free run.

    • cites [127] Andersen, 2010, Early and late rate of force development: Differential adaptive responses to resistance training?, Scand. J. Med. Sci. Sports source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Muscle velocity and muscle power assessment require optimal neuromuscular conditions, and studies analyzing supplement effects on muscular velocity and power selected a maximum of two repetitions with a submaximal load, with recovery periods of 2−5 min.

    “Muscle velocity and muscle power assessment require optimal neuromuscular conditions and, as such, studies analyzing the effect of different supplements on muscular velocity and power selected a maximum of two repetitions with a submaximal load, with recovery periods of 2−5 min [117,118,119,120,121,122].”
    Quote in the paperSubstantial claim0 of 6 sources checked
    • cites [117] Salinero, 2012, Dose response effects of a caffeine-containing energy drink on muscle performance: A repeated measures design, J. Int. Soc. Sports Nutr. source

      Not checked in the free run.

    • cites [118] Ortega, 2015, Improvements on neuromuscular performance with caffeine ingestion depend on the time-of-day, J. Sci. Med. Sport source

      Not checked in the free run.

    • cites [119] Ortega, 2013, Neuromuscular Responses to Incremental Caffeine Doses, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [120] Lougedo, 2018, Effects of β-alanine supplementation during a 5-week strength training program: A randomized, controlled study, J. Int. Soc. Sports Nutr. source

      Not checked in the free run.

    • cites [121] Venier, 2019, Acute Enhancement of Jump Performance, Muscle Strength, and Power in Resistance-Trained Men After Consumption of Caffeinated Chewing Gum, Int. J. Sports Physiol. Perform. source

      Not checked in the free run.

    • cites [122] Romero-Moraleda, B., Del Coso, J., Gutiérrez-Hellín, J., and Lara, B. (2019). The Effect of Caffeine on the Velocity of Half-Squat Exercise during the Menstrual Cycle: A Randomized Controlled Trial. Nutrients, 11. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    These effects could occur independent of changes in the content of Ca2+-handling proteins.

    “Importantly, these effects could occur independent of changes in the content of Ca2+-handling proteins.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Enhanced skeletal muscle contractile function has been observed during electrically stimulated contractions, and enhanced peak power output has been observed during isokinetic dynamometry and cycling exercise.

    “Consistent with the potential for improved weightlifting exercise performance after NO3− supplementation, enhanced skeletal muscle contractile function has been observed during electrically stimulated contractions [95,96,103], and enhanced peak power output has been observed during isokinetic dynamometry [97,123,128] and cycling [45,57,60,129,130,131,132,133] exercise.”
    Quote in the paperSubstantial claim0 of 10 sources checked
    • cites [95] Haider, 2014, Nitrate Supplementation Enhances the Contractile Properties of Human Skeletal Muscle, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [96] Whitfield, 2017, Beetroot Juice Increases Human Muscle Force without Changing Ca2+-Handling Proteins, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [103] Tillin, 2018, Nitrate supplement benefits contractile forces in fatigued but not unfatigued muscle, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [97] Coggan, 2015, Effect of acute dietary nitrate intake on maximal knee extensor speed and power in healthy men and women, Nitric Oxide source

      Not checked in the free run.

    • cites [123] Coggan, 2018, Dietary nitrate-induced increases in human muscle power: High versus low responders, Physiol. Rep. source

      Not checked in the free run.

    • cites [128] Coggan, 2019, A Single Dose of Dietary Nitrate Increases Maximal Knee Extensor Angular Velocity and Power in Healthy Older Men and Women, J. Gerontol. Ser. A Biol. Sci. Med. Sci. source

      Not checked in the free run.

    • cites [45] Thompson, 2015, Dietary nitrate improves sprint performance and cognitive function during prolonged intermittent exercise, Eur. J. Appl. Physiol. source

      Not checked in the free run.

    • cites [57] Jonvik, 2018, Repeated-sprint performance and plasma responses following beetroot juice supplementation do not differ between recreational, competitive and elite sprint athletes, Eur. J. Sport Sci. source

      Not checked in the free run.

    • cites [60] Rimer, 2016, Increase in Maximal Cycling Power with Acute Dietary Nitrate Supplementation, Int. J. Sports Physiol. Perform. source

      Not checked in the free run.

    • cites [129] Cuenca, E., Jodra, P., Pérez-López, A., Rodríguez, L.G.G., Da Silva, S.F., Veiga-Herreros, P., and Domínguez, R. (2018). Effects of Beetroot Juice Supplementation on Performance and Fatigue in a 30-s All-Out Sprint Exercise: A Randomized, Double-Blind Cross-Over Study. Nutrients, 10. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    RyR proteins contain a markedly greater number of sulfhydryl groups compared to other contractile proteins, which supports the proposed hypothesis that NO-mediated RyR modulation and Ca2+ release could contribute to enhanced muscle contractility following NO3− supplementation.

    “In addition, RyR proteins contain a markedly greater number of sulfhydryl groups compared to other contractile proteins [146], which supports the proposed hypothesis that NO-mediated RyR modulation and Ca2+ release could contribute to enhanced muscle contractility following NO3− supplementation [123].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [146] Takeshima, 1989, Primary structure and expression from complementary DNA of skeletal muscle ryanodine receptor, Nature source

      Not checked in the free run.

    • cites [123] Coggan, 2018, Dietary nitrate-induced increases in human muscle power: High versus low responders, Physiol. Rep. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    NaNO2 administration can increase cytosolic [Ca2+] without altering force production at a supraphysiological PO2, or lower cytosolic [Ca2+] concomitant with lower submaximal, but not maximal, force at a physiological PO2, during single evoked isometric contractions in isolated mouse muscle fibers.

    “There is also previous evidence indicating that NaNO2 administration can increase cytosolic [Ca2+] without altering force production at a supraphysiological PO2 [134], or lower cytosolic [Ca2+] concomitant with lower submaximal, but not maximal, force at a physiological PO2 [118], during single evoked isometric contractions in isolated mouse muscle fibers.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [134] Andrade, 1998, Effect of hydrogen peroxide and dithiothreitol on contractile function of single skeletal muscle fibres from the mouse, J. Physiol. source

      Not checked in the free run.

    • cites [118] Ortega, 2015, Improvements on neuromuscular performance with caffeine ingestion depend on the time-of-day, J. Sci. Med. Sport source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Various contractile-related proteins can undergo reversible post-translation modifications at cysteine residues on thiols, such as myosin, troponin, SERCA and ryanodine receptors, and these modifications are likely dependent on interactions between NO, reactive oxygen species and glutathione bioavailability.

    “The potential influence of S-nitrosylation on excitation–contraction coupling is complex given that various contractile-related proteins can undergo reversible post-translation modifications at cysteine residues on thiols, such as myosin [140], troponin [141], SERCA [142] and ryanodine receptors (RyRs) [143,144], and that these post-translation protein modifications are likely dependent on inter”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [140] Nogueira, 2009, Myosin is reversibly inhibited by S-nitrosylation, Biochem. J. source

      Not checked in the free run.

    • cites [141] Dutka, 2017, S-nitrosylation and S-glutathionylation of Cys134 on troponin I have opposing competitive actions on Ca2+ sensitivity in rat fast-twitch muscle fibers, Am. J. Physiol. Physiol. source

      Not checked in the free run.

    • cites [142] Ishii, 1998, Inhibition of skeletal muscle sarcoplasmic reticulum Ca2+-ATPase by nitric oxide, FEBS Lett. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Other studies have not observed changes in EMG after NO3− supplementation, and it is unclear whether NO3− supplementation alters neural drive.

    “However, other studies have not observed changes in EMG after NO3− supplementation [95,103] and, as such, it is unclear whether NO3− supplementation alters neural drive.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [95] Haider, 2014, Nitrate Supplementation Enhances the Contractile Properties of Human Skeletal Muscle, Med. Sci. Sports Exerc. source

      Not checked in the free run.

    • cites [103] Tillin, 2018, Nitrate supplement benefits contractile forces in fatigued but not unfatigued muscle, Med. Sci. Sports Exerc. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    The exact physiological mechanisms responsible for enhanced exercise performance following dietary NO3− supplementation are unclear.

    “Although the exact physiological mechanisms responsible for enhanced exercise performance following dietary NO3− supplementation are unclear, a number of putative mechanisms have been identified which could contribute to improved weightlifting exercise performance.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Taken together, the existing, albeit limited, evidence suggests that acute and short-term dietary NO3− supplementation can enhance weightlifting exercise performance by increasing muscle power production, velocity of contraction and muscular endurance in healthy resistance-trained adults.

    “Taken together, the existing, albeit limited, evidence suggests that acute and short-term dietary NO3− supplementation can enhance weightlifting exercise performance by increasing muscle power production, velocity of contraction and muscular endurance in healthy resistance-trained adults.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    NO3− supplementation has been reported to lower the high-energy phosphate cost of skeletal muscle contractile force production and the intramuscular accumulation of ADP and Pi, factors expected to abate the development of skeletal muscle fatigue.

    “Specifically, NO3− supplementation has been reported to lower the high-energy phosphate cost of skeletal muscle contractile force production [51,94] and the intramuscular accumulation of ADP and Pi [51], factors which would be expected to abate the development of skeletal muscle fatigue [102].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [51] Bailey, 2010, Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [94] Fulford, 2013, Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions, Pflüg. Arch. source

      Not checked in the free run.

    • cites [102] Allen, 2008, Skeletal Muscle Fatigue: Cellular Mechanisms, Physiol. Rev. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The results are incongruous with inconsistencies likely linked to differences in supplementation strategies and exercise modality.

    “However, the results are incongruous with inconsistencies likely linked to differences in supplementation strategies and exercise modality.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Another mechanism that could improve skeletal muscle contractile function after NO3− supplementation is post-translational modification of skeletal muscle contractile or Ca2+-handling proteins.

    “Another mechanism that could improve skeletal muscle contractile function after NO3− supplementation is the post-translational modification of the skeletal muscle contractile or Ca2+-handling proteins [136].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [136] Nyakayiru, 2017, Sodium nitrate ingestion increases skeletal muscle nitrate content in humans, J. Appl. Physiol. source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    While NO3− supplementation appears to potentially enhance resistance training quality, it is unclear if this will translate into improved weightlifting training adaptations.

    “Furthermore, while NO3− supplementation appears to potentially enhance resistance training quality, it is unclear if this will translate into improved weightlifting training adaptations.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Dietary NO3− supplementation has also been shown to increase muscle blood flow, which might aid muscle PCr resynthesis between sets to failure and the recovery of force and performance.

    “Dietary NO3− supplementation has also been shown to increase muscle blood flow [109], which might aid muscle PCr resynthesis between sets to failure [107,108] and the recovery of force and performance [104,105,106].”
    Quote in the paperSubstantial claim0 of 6 sources checked
    • cites [109] Ferguson, 2012, Impact of dietary nitrate supplementation via beetroot juice on exercising muscle vascular control in rats, J. Physiol. source

      Not checked in the free run.

    • cites [107] Trump, 1996, Importance of muscle phosphocreatine during intermittent maximal cycling, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [108] Vanhatalo, 2011, Dietary nitrate reduces muscle metabolic perturbation and improves exercise tolerance in hypoxia, J. Physiol. source

      Not checked in the free run.

    • cites [104] Bogdanis, 1995, Recovery of power output and muscle metabolites following 30 s of maximal sprint cycling in man, J. Physiol. source

      Not checked in the free run.

    • cites [105] Bogdanis, 1996, Contribution of phosphocreatine and aerobic metabolism to energy supply during repeated sprint exercise, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [106] Gaitanos, 1993, Human muscle metabolism during intermittent maximal exercise, J. Appl. Physiol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    NO3− supplementation has been reported to enhance the adaptations to sprint interval training.

    “Notably, although NO3− supplementation has been reported to enhance the adaptations to sprint interval training [62,147], the molecular bases for skeletal muscle oxidative metabolism and hypertrophy training adaptations are different and can be potentially antagonistic [148,149].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [62] Thompson, 2016, Influence of dietary nitrate supplementation on physiological and muscle metabolic adaptations to sprint interval training, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [147] Thompson, 2018, Discrete physiological effects of beetroot juice and potassium nitrate supplementation following 4-wk sprint interval training, J. Appl. Physiol. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The molecular bases for skeletal muscle oxidative metabolism and hypertrophy training adaptations are different and can be potentially antagonistic.

    “Notably, although NO3− supplementation has been reported to enhance the adaptations to sprint interval training [62,147], the molecular bases for skeletal muscle oxidative metabolism and hypertrophy training adaptations are different and can be potentially antagonistic [148,149].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [148] Coffey, 2016, Concurrent exercise training: Do opposites distract?, J. Physiol. source

      Not checked in the free run.

    • cites [149] Fyfe, 2014, Interference between Concurrent Resistance and Endurance Exercise: Molecular Bases and the Role of Individual Training Variables, Sports Med. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The potential candidate mechanisms for improved weightlifting exercise performance after NO3− supplementation include enhanced excitation-contraction coupling via modulation of Ca2+-handling and contractile proteins; improved skeletal muscle metabolic control via lowering the high-energy phosphate cost of contraction and fatigue-related metabolite accumulation; and improved skeletal muscle PerfUSI

    “The potential candidate mechanisms for improved weightlifting exercise performance after NO3− supplementation include enhanced excitation–contraction coupling, via modulation of Ca2+-handling and contractile proteins [98,134,135,139]; improved skeletal muscle metabolic control, via lowering the high-energy phosphate cost of contraction and fatigue-related metabolite accumulation [51,94]; and”
    Quote in the paperSubstantial claim0 of 7 sources checked
    • cites [98] Schiffer, 2012, Dietary nitrate increases tetanic [Ca2+]i and contractile force in mouse fast-twitch muscle, J. Physiol. source

      Not checked in the free run.

    • cites [134] Andrade, 1998, Effect of hydrogen peroxide and dithiothreitol on contractile function of single skeletal muscle fibres from the mouse, J. Physiol. source

      Not checked in the free run.

    • cites [135] Bailey, 2019, Incubation with sodium nitrite attenuates fatigue development in intact single mouse fibres at physiological, J. Physiol. source

      Not checked in the free run.

    • cites [139] Evangelista, A.M., Rao, V.S., Filo, A.R., Marozkina, N.V., Doctor, A., Jones, D.R., Gaston, B., and Guilford, W. (2010). Direct Regulation of Striated Muscle Myosins by Nitric Oxide and Endogenous Nitrosothiols. PLoS ONE, 5. source

      Not checked in the free run.

    • cites [51] Bailey, 2010, Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans, J. Appl. Physiol. source

      Not checked in the free run.

    • cites [94] Fulford, 2013, Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions, Pflüg. Arch. source

      Not checked in the free run.

    • cites [109] Ferguson, 2012, Impact of dietary nitrate supplementation via beetroot juice on exercising muscle vascular control in rats, J. Physiol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    The mechanistic bases responsible for the potential ergogenic effect of NO3− supplementation on weightlifting exercise performance may be linked to improvements in skeletal muscle excitation-contraction coupling, high-energy phosphate metabolism and perfusion.

    “The mechanistic bases responsible for the potential ergogenic effect of NO3− supplementation on weightlifting exercise performance may be linked to improvements in skeletal muscle excitation–contraction coupling, high-energy phosphate metabalism and perfusion.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Taken together, the existing evidence suggests that NO3− supplementation can improve skeletal muscle contractile function and might enhance weightlifting exercise performance in humans.

    “Taken together, the existing evidence suggests that NO3− supplementation can improve skeletal muscle contractile function and might enhance weightlifting exercise performance in humans.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    NO3− supplementation can improve muscular power production, velocity of contraction, and the number of repetitions to failure during weightlifting exercise.

    “Indeed, NO3− supplementation can improve muscular power production, velocity of contraction, and the number of repetitions to failure during weightlifting exercise.”
    Quote in the paperSubstantial claim
48 of 48

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Reference [150] names a different kinase from the one attributed to it

    Minor

    The text attributes AMPK activation to reference [150], but the cited reference's title says that nitrite activates protein kinase A. AMPK and protein kinase A are different kinases.

1 of 1

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Related

Authors
San Juan, A. F., Dominguez, R., Lago-Rodríguez, Á., Montoya, J. J., Tan, R., & Bailey, S. J.
Affiliations
  • Department of Health and Human Performance, Sport Biomechanics Laboratory, Facultad de Ciencias de la Actividad Física y del Deporte—INEF, Universidad Politécnica de Madrid, 28040 Madrid, Spain
  • Faculty of Health Science, Universidad Isabel I, 09003 Burgos, Spain
  • Universidad Isabel I (ES)
  • Universidad Complutense de Madrid (ES)
  • Pepperdine University (US)
  • Loughborough University (GB)
ORCID
Venue
Nutrients
Publisher
MDPI AG
Published
2020-07-26
Volume
12
Issue
8
Pages
2227
ISSN
2072-6643 (ISSN-L)
DOI
10.3390/nu12082227
PMC
PMC7469052
OpenAlex
W3045438527
Semantic Scholar
db696aa396a43aea0755cf32c6e4aa274f1579af
Cited by
36
References
154
Citations by year
2026: 4 · 2025: 7 · 2024: 4 · 2023: 5 · 2022: 10 · 2021: 4 · 2020: 2
FWCI
0.61
Type
journal article
Language
en
Open access
Licence
Locations
  • Nutrients (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Figshare (submittedVersion, cc-by)
  • Pepperdine Digital Commons (Pepperdine University) (submittedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
  • Health Sciences › Medicine › Rehabilitation › Exercise and Physiological Responses
Keywords
dietary nitrate, nitrate supplementation, beetroot, weightlifting, resistance exercise performance, ergogenic aids, muscle power, muscular endurance, repetitions to failure, fast-twitch muscle, bench press, back squat
MeSH terms
Adult, Humans, Male, Nitrates, Physical Endurance, Weight Lifting, Muscle, Skeletal, Dietary Supplements, Athletic Performance, Resistance Training, Performance-Enhancing Substances, Healthy Volunteers

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review