Learn which ones may have…. In this edition of Medical Myths, we tackle some persistent myths about supplements, including multivitamins, probiotics, and antioxidants. Vitamin A supplements come in many different forms, but a person should check with their doctor which form and dosage will best suit them.

Read more…. Vitamin B complex supplements may help to prevent vitamin B deficiency. Learn more here. HUM nutrition offers a range of products to support a person's health. Here is our review for My podcast changed me Can 'biological race' explain disparities in health?

Why Parkinson's research is zooming in on the gut Tools General Health Drugs A-Z Health Hubs Health Tools Find a Doctor BMI Calculators and Charts Blood Pressure Chart: Ranges and Guide Breast Cancer: Self-Examination Guide Sleep Calculator Quizzes RA Myths vs Facts Type 2 Diabetes: Managing Blood Sugar Ankylosing Spondylitis Pain: Fact or Fiction Connect About Medical News Today Who We Are Our Editorial Process Content Integrity Conscious Language Newsletters Sign Up Follow Us.

Medical News Today. Health Conditions Health Products Discover Tools Connect. Vitamins and supplements for athletes.

Medically reviewed by Miho Hatanaka, RDN, L. B vitamins Iron Calcium and vitamin D Coenzyme Q10 Creatine Ashwagandha Summary. How we vet brands and products Medical News Today only shows you brands and products that we stand behind. Our team thoroughly researches and evaluates the recommendations we make on our site.

To establish that the product manufacturers addressed safety and efficacy standards, we: Evaluate ingredients and composition: Do they have the potential to cause harm?

Fact-check all health claims: Do they align with the current body of scientific evidence? Assess the brand: Does it operate with integrity and adhere to industry best practices? We do the research so you can find trusted products for your health and wellness.

Read more about our vetting process. Was this helpful? B vitamins. Share on Pinterest A number of of vitamins and supplements may provide athletes with an added energy boost.

Calcium and vitamin D. Coenzyme Q Further resources For more in-depth resources about vitamins, minerals, and supplements, visit our dedicated hub. How we reviewed this article: Sources. Medical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations.

We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. Within the muscle, creatine-kinase mediates the phosphorylation of creatine to phosphocreatine PCr , a key substrate for high-intensity muscle force generation Greenhaff et al.

As a result, creatine loading can acutely enhance the performance of sports involving repeated high-intensity exercise e. There is additional, albeit equivocal, evidence of changes in cellular signaling, metabolism, and water storage associated with creatine supplementation with potential flow-on effects such as enhancements of protein synthesis, glycogen storage, and thermoregulation for review, see Cooper et al.

Therefore, there may be less well-recognized benefits of creatine supplementation for endurance sport athletes. Such protocols have been established primarily from early work investigating muscle creatine loading in males Hultman et al.

No negative health effects have been reported with the long-term use of CM up to 4 years when appropriate loading protocols are followed Schilling et al.

In fact, some reports propose CM supplementation to be anti-inflammatory, and to reduce exercise-induced oxidative stress Deminice et al. Dietary nitrate NO 3 — is a popular supplement initially found to improve oxygen uptake VO 2 kinetics during prolonged submaximal exercise Bailey et al.

The ingestion of dietary NO 3 — leads to an enhanced nitric oxide NO bioavailability via the NO 3 — -nitrite-NO pathway, a reduction catalyzed initially by bacteria in the mouth and the digestive system Duncan et al.

NO plays an important role in the modulation of skeletal muscle function Jones, , with proposed mechanisms for improved exercise performance including a reduced ATP cost of muscle force production, an increased efficiency of mitochondrial respiration, increased blood flow to the muscle, and a decrease in blood flow to VO 2 heterogeneities Bailey et al.

Recently, nitrate supplementation has been proposed to enhance the function of type II muscle fibers Bailey et al. Differences in these findings may possibly relate to the lower dose of nitrate provided in the acute instance; indeed, a dose-response effect of NO 3 — supplement use has been shown previously, with higher NO 3 — doses having a greater impact on 2,m rowing performance Hoon et al.

However, the benefit of nitrate supplementation for very highly-trained elite athletes requires more research, with some Nyakayiru et al. Finally, chronic NO 3 — supplementation may facilitate training adaptations when taken prior to key sessions, with greater improvements 8.

Leafy green and root vegetables i. Performance benefits may manifest acutely i. Finally, performance benefits may be maintained for at least 15 days, if consumption of the supplement is continued for this duration Vanhatalo et al.

Beta-alanine is the rate-limiting precursor to carnosine, an endogenous intracellular muscle buffer, and one of the immediate defenses against the accumulation of protons in the contracting musculature during exercise Lancha Junior et al.

Daily supplementation with 3. Beta-alanine supplementation may not be as effective in well-trained athletes as their lesser-trained counterparts Bellinger, , partly due to a diminishing role of carnosine toward intramuscular pH regulation in individuals with an already enhanced buffering capacity.

However, the small performance changes observed in well-trained athletes to date 0. Beta-alanine dosing strategies typically involve split doses consumed over the day i. However, in accounting for this individual variation, an in-depth analysis and summary of the available literature by Stellingwerff et al.

Regardless, it is likely that an individualized approach to beta-alanine supplementation should be considered where possible. Ingestion of sodium bicarbonate NaHCO 3 is proposed to enhance high-intensity exercise performance as an extracellular blood buffer; however, the mechanisms of action are complex Siegler et al.

Although playing an important role in the maintenance of both intracellular and extracellular pH, NaHCO 3 is unable to permeate the sarcolemma, and therefore aids intracellular pH regulation indirectly by raising both extracellular pH and HCO 3 — concentrations Katz et al.

Successful supplementation protocols typically involve acute NaHCO 3 doses of 0. However, common side effects include GI upset, which may negate any performance enhancements, likely explaining the large variability in individual responses Carr, Slater, et al.

Furthermore, sodium citrate has been proposed as an alternative to NaHCO 3 , as a result of lower reported rates albeit not in all investigations of GI upset Requena et al.

Potentially, the aforementioned supplement doses and performance effects are achievable from slightly-elevated dietary consumption of commonly-consumed foods and beverages i. Regardless, it is no doubt reassuring that each of these established performance supplements can be found in various forms on the shelves and in the fridges of the local supermarket.

The following supplements are also used by athletes; however, the evidence-base for their potential to enhance athletic performance is less clear.

Similar to NaHCO 3 , sodium citrate acts as a blood buffer by increasing pH in the extracellular environment, and increasing the gradient between the blood and the active muscle. Early studies trialed sodium citrate doses ranging from 0. Here, a dose response was seen, with ergogenic benefits requiring a minimum ingestion of 0.

Subsequently, a 0. The more recent discovery that the time to peak blood pH occurs — min after sodium citrate ingestion suggests that the dosing protocol should occur at a minimum of 3 hr preexercise Urwin et al. Despite these few positive investigations, it should be noted that the ergogenic effect of sodium citrate ingestion remains equivocal, with a previous meta-analysis highlighting a negligible benefit 0.

Considering the detrimental side effects from both NaHCO 3 and citrate, and the potential for limited benefits with the latter, athletes and support staff are encouraged to carefully trial the use of these blood buffers in training before implementing an individualized and bespoke protocol in a competition setting.

Numerous hypotheses have been proposed to support the potential benefits of phosphate supplementation on athletic performance see Buck et al.

The proposed mechanisms underpinning these benefits include an enhanced rate of ATP and PCr resynthesis Kreider, ; improved buffering capacity to support high rates of anaerobic glycolysis Kreider, ; improvement of myocardial contractility leading to increased cardiac efficiency Kreider et al.

Overall, there is equivocal evidence of performance enhancement from phosphate supplementation. In some instances, phosphate has been shown to enhance VO 2max Cade et al. However, in the case of repeated sprints, the magnitude of benefit has been shown to be varied and unclear Kopec et al, Finally, there is also a large amount of contrary evidence from the same physiological and performance measures that suggests phosphate supplementation in isolation, or in combination with other buffer agents has no impact on exercise capacity or performance outcomes Brewer et al.

No doubt, the lack of clear consensus defined by this collective work is explained by variations in the supplement protocol used i. as well as individual responses to the supplement itself Peeling, This is often associated with GI distress Cade et al.

Nevertheless, current evidence regarding the efficacy of phosphate supplementation remains unclear, since there exists no evidence to suggest an accumulation of this supplement in the muscle, where a number of the reported mechanism are suggested to take effect.

As such, the use of this supplement for enhanced athletic performance is likely questionable, with further research needed to fully explore its true effect.

If considered for use, individual responses should be thoroughly trialed prior to using this supplement in a competition setting. Increased muscle carnitine stores via supplementation with L-carnitine are postulated to spare glycogen, via increased fat oxidation, at lower exercise intensities, and to promote more efficient carbohydrate oxidation and reduced lactate accumulation at higher intensities, delaying the onset of fatigue during endurance-based activity.

Research on L-carnitine supplementation has shown equivocal outcomes. Marconi et al. Of note, the lack of performance effect seen in these studies may likely result from the fact that muscle carnitine levels do not seem to increase when using these standard supplement protocols i.

More recently, Novakova et al. Importantly, there was no effect on muscle function, energy metabolism, or VO 2 during either submaximal or maximal exercise tests.

It is likely that the lack of efficacy of oral L-carnitine supplementation in many studies is due to its low bioavailability and failure to increase muscle carnitine stores. However, Stephens, Evans, et al. In a follow-up study Wall et al. Therefore, given the limited research in this space, and the considerable effort needed to implement such a protocol, further investigation is needed to clarify the efficacy and safety of following these prolonged supplement regimes.

This section covers supplements which are emerging in both their popularity and the evidence base for athletic performance benefits. However, more work is needed before conclusive recommendations can be made on their use, and there may be some differences in the principles or mechanisms by which they could be of value.

The performance supplements outlined in the prior sections are presented in view of a strong evidence base to reflect a direct impact on athletic performance through the augmentation of various rate-limiting processes.

However, other supplements may have an indirect impact on performance via their ability to support the training process, through their influence on factors such as inflammatory modulation, oxidative stress, and signaling pathways for adaptation, or their ability to support repetitive performance by restoring homeostasis between two exercise bouts.

Such an outcome may impact athlete performance—for instance, if the supplement protocol targets an improvement in fatigue resistance during heavy competition schedules. Similarly, food polyphenols may act in a comparable way, possessing strong anti-oxidant and anti-inflammatory properties see Tsao, that may be beneficial to exercise recovery.

For instance, the high anthocyanin content of tart Montmorency cherries has been shown to reduce the inflammatory and oxidative stress responses to marathon running Howatson et al. Of note, only blood biomarkers were presented in these aforementioned studies to suggest such a benefit and, therefore, these outcomes should be further confirmed by muscle analysis in future research.

Of note, there are several issues that make it more difficult to substantiate the performance benefits of these supplements. One factor is that it may take a lengthy period before better recovery between exercise bouts or better support of training leads to a detectable improvement in competition performance.

For example, previous research on supplementation with anti-oxidant vitamins i. As such, the ultimate benefit of the use of these supplements may depend on how and when they are used; for example, they might be used in scenarios of repeated competition events to reduce exercise perturbations and enhance recovery and subsequent performance, but avoided during training bouts where optimal adaptation is driven by full exposure to oxidative or inflammatory stress.

Alternatively, some supplements may affect a number of body systems, with positive effects on one system counteracting the minor negative effects on another.

For example, although they are considered to have anti-oxidant properties, some polyphenol subclasses e. Furthermore, numerous food polyphenols are also suggested to have a direct effect on performance, potentially a result of mechanisms relevant to flow mediated dilatation, NO production, and adenosine receptor antagonism effects Somerville et al.

However, clearly in its infancy, there exists a need for further research exploring these emerging supplements to fully examine the effects and potential efficacy of their ability to support the training process, and to provide a direct positive impact on athletic performance.

This review summarizes the evidence for a number of commonly-used supplements, ingested with the aim of enhancing athletic performance. This should be further viewed in light of the marginal, but often important, gains that may be achieved through sound use of these products, as well as practical considerations such as a lack of uniform tolerance and response to a given supplement.

As such, any use of performance supplements should be thoroughly trialed in training before implementation into a competition environment, since, in some scenarios, outcomes ranging from a lack of efficacy to deleterious responses may outweigh any expected performance enhancement.

Astorino , T. Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: A systematic review. PubMed doi Baguet , A. Important role of muscle carnosine in rowing performance. Journal of Applied Physiology , 4 , — Bailey , S.

Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans. Journal of Applied Physiology , 1 , — Inorganic nitrate supplementation improves muscle oxygenation, O 2 uptake kinetics, and exercise tolerance at high but not low pedal rates.

Journal of Applied Physiology , 11 , — Dietary nitrate supplementation reduces the O 2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. Barnett , C. Effect of L-carnitine supplementation on muscle and blood carnitine content and lactate accumulation during high-intensity sprint cycling.

International Journal of Sport Nutrition, 4 3 , — Baylis , A. Inadvertent doping through supplement use by athletes: Assessment and management of the risk in Australia. International Journal of Sport Nutrition and Exercise Metabolism, 11 3 , — Bell , P.

Montmorency cherries reduce the oxidative stress and inflammatory responses to repeated days high-intensity stochastic cycling.

Nutrients, 6 12 , — Bellar , D. Effects of low-dose caffeine supplementation on early morning performance in the standing shot put throw. European Journal of Sport Science, 12 1 , 57 — Bellinger , P.

Beta-Alanine supplementation for athletic performance: An update. Benesch , R. Intracellular organic phosphates as regulators of oxygen release by haemoglobin. Nature, , — Boorsma , R. Beetroot juice supplementation does not improve performance of elite m runners.

Braakhuis , A. Impact of dietary antioxidants on sport performance: A review. Sports Medicine, 45 7 , — Branch , J. Effect of creatine supplementation on body composition and performance: A meta-analysis.

International Journal of Sport Nutrition and Exercise Metabolism, 13 2 , — Brewer , C. Effect of repeated sodium phosphate loading on cycling time-trial performance and VO2peak.

International Journal of Sport Nutrition and Exercise Metabolism, 23 2 , — Effect of sodium phosphate supplementation on cycling time trial performance and VO2 1 and 8 days post loading.

Bruce , C. Enhancement of m rowing performance after caffeine ingestion. Buck , C. Sodium phosphate as an ergogenic aid. Sports Medicine, 43 6 , — Buford , T. International Society of Sports Nutrition position stand: Creatine supplementation and exercise. Journal of the International Society of Sports Nutrition, 4 , 6.

Burke , L. Caffeine and sports performance. Applied Physiology Nutrition and Metabolism, 33 6 , — Practical considerations for bicarbonate loading and sports performance. Nestlé Nutrition Institute Workshop Series, 75 , 15 — Cade , R.

Effects of phosphate loading on 2, 3-diphosphoglycerate and maximal oxygen uptake. Carr , A. Effects of acute alkalosis and acidosis on performance: A meta-analysis. Sports Medicine, 41 10 , — International Journal of Sport Nutrition and Exercise Metabolism, 21 3 , — Chung , W.

Effect of 10 week beta-alanine supplementation on competition and training performance in elite swimmers. Nutrients, 4 12 , — Cook , M. New Zealand blackcurrant extract improves cycling performance and fat oxidation in cyclists. European Journal of Applied Physiology, 11 , — Even if mud runs aren't your thing, creatine has been shown to improve performance on the playing field, as well.

Research has demonstrated improvements in power output, muscular endurance, and sprint performance in sports like soccer, hockey, rugby, and football.

Looking to shave seconds off your 5K time or improve the accuracy of your passes on the soccer field? Yes, caffeine has been suggested to help you do those things!

Caffeine is a well-documented ergogenic aid in performance research, and its use in sports dates all the way back to the s. Most of us consume caffeine because of its ability to increase alertness how else are we going to make it through a work day?

Whether you like to spend your weekends on the rugby field or trying to set PRs in the gym, current research supports the benefits of caffeine in sports and high-intensity intermittent exercise. Because many fitness activities are played outdoors in the heat and humidity or in poorly ventilated gyms, maintaining proper hydration status is critical for optimal performance.

If you're limited to water breaks, make sure to consume ounces of fluid hours prior to your activity, and another 8 ounces right before you start play. After competition, begin rehydrating immediately, aiming to get in another ounces of fluids for every pound of bodyweight you lost via sweat.

It's mile five of the Tough Mudder and you still have ditches to hurdle, ladders to climb, and walls to scale. When pride and bragging rights between you and your buddies are at stake, you need all the help you can get!

Enter beta-alanine. During high-intensity activity, your body accumulates hydrogen ions, causing a drop in your pH level, ultimately resulting in fatigue. Beta-alanine supplementation has been shown to increase intramuscular carnosine content, thereby increasing the body's ability to buffer hydrogen ions and delay fatigue.

Beta-alanine supplementation can help improve your exercise performance and training volume, which will ultimately help solidify your right to gloat for another year.

Research Results by Date NCCIH Research Blog Division of Extramural Research Sponsored by NCCIH Division of Intramural Research Conducted at NCCIH Resources for Researchers Clinical Trials NIH Pain Research Center.

Home Health Information Bodybuilding and Performance Enhancement Supplements: What You Need To Know. Bodybuilding and Performance Enhancement Supplements: What You Need To Know. Why do some bodybuilders and athletes take dietary supplements?

What dietary supplements are banned by the NCAA? Are dietary supplements necessary? What is creatine? Is creatine safe?

Do performance-enhancing dietary supplements work? Are bodybuilding supplements safe? Dangerous hidden ingredients are an increasing problem in products promoted for bodybuilding, the U. Food and Drug Administration FDA warns. Consumers may unknowingly take products laced with prescription drug ingredients, controlled substances, and other ingredients.

Bodybuilding supplements often are adulterated with anabolic steroids that are modified variants of male hormones designed to increase muscle mass. Liver injury from taking bodybuilding dietary supplements has increased in recent years. Bodybuilding products are the most common cause of liver injury linked to herbal and dietary supplement use.

Products containing the stimulants BMPEA or DMAA can cause serious health problems. DMAA-containing products marketed as dietary supplements are illegal. In , the FDA began taking action to remove these products from the market. However, DMAA is still found in some products marketed as supplements, including under different names, such as geranium oil.

Some dietary supplements may interact with drugs or other supplements. Some vitamins and minerals are harmful at high doses.

Talk with your health care provider before using a dietary supplement for bodybuilding or endurance. For More Information. NCCIH Clearinghouse The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature.

Toll-free in the U. gov Email: info nccih. Know the Science NCCIH and the National Institutes of Health NIH provide tools to help you understand the basics and terminology of scientific research so you can make well-informed decisions about your health.

Explaining How Research Works NIH Know the Science: How To Make Sense of a Scientific Journal Article Understanding Clinical Studies NIH.

PubMed® A service of the National Library of Medicine, PubMed® contains publication information and in most cases brief summaries of articles from scientific and medical journals. Office of Dietary Supplements ODS , National Institutes of Health NIH ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public.

gov Email: ods nih. Food and Drug Administration FDA The FDA oversees the safety of many products, such as foods, medicines, dietary supplements, medical devices, and cosmetics.

Center for Food Safety and Applied Nutrition CFSAN Part of the FDA, CFSAN oversees the safety and labeling of supplements, foods, and cosmetics. Federal Trade Commission FTC The FTC is the Federal agency charged with protecting the public against unfair and deceptive business practices.

MedlinePlus To provide resources that help answer health questions, MedlinePlus a service of the National Library of Medicine brings together authoritative information from the National Institutes of Health as well as other Government agencies and health-related organizations. Dietary Supplement Label Database The Dietary Supplement Label Database—a project of the National Institutes of Health—has all the information found on labels of many brands of dietary supplements marketed in the United States.

Key References. Alvares TS, Conte-Junior CA, Silva JT, et al. L-arginine does not improve biochemical and hormonal response in trained runners after 4 weeks of supplementation. Nutrition Research. Austin KG, McLellan TM, Farina EK, et al. Soldier use of dietary supplements, including protein and body building supplements, in a combat zone is different than use in garrison.

Applied Physiology, Nutrition, and Metabolism. Bellinger PM. β-Alanine supplementation for athletic performance: an update.

Journal of Strength and Conditioning Research. Candow DG, Chilibeck PD, Forbes SC. Creatine supplementation and aging musculoskeletal health.

Deminice R, Rosa FT, Franco GS, et al. Effects of creatine supplementation on oxidative stress and inflammatory markers after repeated-sprint exercise in humans.

Herriman M, Fletcher L, Tchaconas A, et al. Dietary supplements and young teens: misinformation and access provided by retailers. Knapik JJ, Steelman RA, Hoedebecke SS, et al. Prevalence of dietary supplement use by athletes: systematic review and meta-analysis.

Sports Medicine. Ko R, Low Dog T, Gorecki DK, et al. Evidence-based evaluation of potential benefits and safety of beta-alanine supplementation for military personnel. Potentially, the aforementioned supplement doses and performance effects are achievable from slightly-elevated dietary consumption of commonly-consumed foods and beverages i.

Regardless, it is no doubt reassuring that each of these established performance supplements can be found in various forms on the shelves and in the fridges of the local supermarket. The following supplements are also used by athletes; however, the evidence-base for their potential to enhance athletic performance is less clear.

Similar to NaHCO 3 , sodium citrate acts as a blood buffer by increasing pH in the extracellular environment, and increasing the gradient between the blood and the active muscle.

Early studies trialed sodium citrate doses ranging from 0. Here, a dose response was seen, with ergogenic benefits requiring a minimum ingestion of 0. Subsequently, a 0. The more recent discovery that the time to peak blood pH occurs — min after sodium citrate ingestion suggests that the dosing protocol should occur at a minimum of 3 hr preexercise Urwin et al.

Despite these few positive investigations, it should be noted that the ergogenic effect of sodium citrate ingestion remains equivocal, with a previous meta-analysis highlighting a negligible benefit 0. Considering the detrimental side effects from both NaHCO 3 and citrate, and the potential for limited benefits with the latter, athletes and support staff are encouraged to carefully trial the use of these blood buffers in training before implementing an individualized and bespoke protocol in a competition setting.

Numerous hypotheses have been proposed to support the potential benefits of phosphate supplementation on athletic performance see Buck et al.

The proposed mechanisms underpinning these benefits include an enhanced rate of ATP and PCr resynthesis Kreider, ; improved buffering capacity to support high rates of anaerobic glycolysis Kreider, ; improvement of myocardial contractility leading to increased cardiac efficiency Kreider et al.

Overall, there is equivocal evidence of performance enhancement from phosphate supplementation. In some instances, phosphate has been shown to enhance VO 2max Cade et al.

However, in the case of repeated sprints, the magnitude of benefit has been shown to be varied and unclear Kopec et al, Finally, there is also a large amount of contrary evidence from the same physiological and performance measures that suggests phosphate supplementation in isolation, or in combination with other buffer agents has no impact on exercise capacity or performance outcomes Brewer et al.

No doubt, the lack of clear consensus defined by this collective work is explained by variations in the supplement protocol used i. as well as individual responses to the supplement itself Peeling, This is often associated with GI distress Cade et al.

Nevertheless, current evidence regarding the efficacy of phosphate supplementation remains unclear, since there exists no evidence to suggest an accumulation of this supplement in the muscle, where a number of the reported mechanism are suggested to take effect. As such, the use of this supplement for enhanced athletic performance is likely questionable, with further research needed to fully explore its true effect.

If considered for use, individual responses should be thoroughly trialed prior to using this supplement in a competition setting. Increased muscle carnitine stores via supplementation with L-carnitine are postulated to spare glycogen, via increased fat oxidation, at lower exercise intensities, and to promote more efficient carbohydrate oxidation and reduced lactate accumulation at higher intensities, delaying the onset of fatigue during endurance-based activity.

Research on L-carnitine supplementation has shown equivocal outcomes. Marconi et al. Of note, the lack of performance effect seen in these studies may likely result from the fact that muscle carnitine levels do not seem to increase when using these standard supplement protocols i.

More recently, Novakova et al. Importantly, there was no effect on muscle function, energy metabolism, or VO 2 during either submaximal or maximal exercise tests.

It is likely that the lack of efficacy of oral L-carnitine supplementation in many studies is due to its low bioavailability and failure to increase muscle carnitine stores.

However, Stephens, Evans, et al. In a follow-up study Wall et al. Therefore, given the limited research in this space, and the considerable effort needed to implement such a protocol, further investigation is needed to clarify the efficacy and safety of following these prolonged supplement regimes.

This section covers supplements which are emerging in both their popularity and the evidence base for athletic performance benefits. However, more work is needed before conclusive recommendations can be made on their use, and there may be some differences in the principles or mechanisms by which they could be of value.

The performance supplements outlined in the prior sections are presented in view of a strong evidence base to reflect a direct impact on athletic performance through the augmentation of various rate-limiting processes. However, other supplements may have an indirect impact on performance via their ability to support the training process, through their influence on factors such as inflammatory modulation, oxidative stress, and signaling pathways for adaptation, or their ability to support repetitive performance by restoring homeostasis between two exercise bouts.

Such an outcome may impact athlete performance—for instance, if the supplement protocol targets an improvement in fatigue resistance during heavy competition schedules.

Similarly, food polyphenols may act in a comparable way, possessing strong anti-oxidant and anti-inflammatory properties see Tsao, that may be beneficial to exercise recovery.

For instance, the high anthocyanin content of tart Montmorency cherries has been shown to reduce the inflammatory and oxidative stress responses to marathon running Howatson et al.

Of note, only blood biomarkers were presented in these aforementioned studies to suggest such a benefit and, therefore, these outcomes should be further confirmed by muscle analysis in future research.

Of note, there are several issues that make it more difficult to substantiate the performance benefits of these supplements. One factor is that it may take a lengthy period before better recovery between exercise bouts or better support of training leads to a detectable improvement in competition performance.

For example, previous research on supplementation with anti-oxidant vitamins i. As such, the ultimate benefit of the use of these supplements may depend on how and when they are used; for example, they might be used in scenarios of repeated competition events to reduce exercise perturbations and enhance recovery and subsequent performance, but avoided during training bouts where optimal adaptation is driven by full exposure to oxidative or inflammatory stress.

Alternatively, some supplements may affect a number of body systems, with positive effects on one system counteracting the minor negative effects on another. For example, although they are considered to have anti-oxidant properties, some polyphenol subclasses e.

Furthermore, numerous food polyphenols are also suggested to have a direct effect on performance, potentially a result of mechanisms relevant to flow mediated dilatation, NO production, and adenosine receptor antagonism effects Somerville et al. However, clearly in its infancy, there exists a need for further research exploring these emerging supplements to fully examine the effects and potential efficacy of their ability to support the training process, and to provide a direct positive impact on athletic performance.

This review summarizes the evidence for a number of commonly-used supplements, ingested with the aim of enhancing athletic performance.

This should be further viewed in light of the marginal, but often important, gains that may be achieved through sound use of these products, as well as practical considerations such as a lack of uniform tolerance and response to a given supplement.

As such, any use of performance supplements should be thoroughly trialed in training before implementation into a competition environment, since, in some scenarios, outcomes ranging from a lack of efficacy to deleterious responses may outweigh any expected performance enhancement.

Astorino , T. Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: A systematic review. PubMed doi Baguet , A. Important role of muscle carnosine in rowing performance.

Journal of Applied Physiology , 4 , — Bailey , S. Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans. Journal of Applied Physiology , 1 , — Inorganic nitrate supplementation improves muscle oxygenation, O 2 uptake kinetics, and exercise tolerance at high but not low pedal rates.

Journal of Applied Physiology , 11 , — Dietary nitrate supplementation reduces the O 2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. Barnett , C. Effect of L-carnitine supplementation on muscle and blood carnitine content and lactate accumulation during high-intensity sprint cycling.

International Journal of Sport Nutrition, 4 3 , — Baylis , A. Inadvertent doping through supplement use by athletes: Assessment and management of the risk in Australia. International Journal of Sport Nutrition and Exercise Metabolism, 11 3 , — Bell , P.

Montmorency cherries reduce the oxidative stress and inflammatory responses to repeated days high-intensity stochastic cycling. Nutrients, 6 12 , — Bellar , D. Effects of low-dose caffeine supplementation on early morning performance in the standing shot put throw.

European Journal of Sport Science, 12 1 , 57 — Bellinger , P. Beta-Alanine supplementation for athletic performance: An update. Benesch , R. Intracellular organic phosphates as regulators of oxygen release by haemoglobin. Nature, , — Boorsma , R. Beetroot juice supplementation does not improve performance of elite m runners.

Braakhuis , A. Impact of dietary antioxidants on sport performance: A review. Sports Medicine, 45 7 , — Branch , J. Effect of creatine supplementation on body composition and performance: A meta-analysis. International Journal of Sport Nutrition and Exercise Metabolism, 13 2 , — Brewer , C.

Effect of repeated sodium phosphate loading on cycling time-trial performance and VO2peak. International Journal of Sport Nutrition and Exercise Metabolism, 23 2 , — Effect of sodium phosphate supplementation on cycling time trial performance and VO2 1 and 8 days post loading.

Bruce , C. Enhancement of m rowing performance after caffeine ingestion. Buck , C. Sodium phosphate as an ergogenic aid. Sports Medicine, 43 6 , — Buford , T.

International Society of Sports Nutrition position stand: Creatine supplementation and exercise. Journal of the International Society of Sports Nutrition, 4 , 6. Burke , L. Caffeine and sports performance.

Applied Physiology Nutrition and Metabolism, 33 6 , — Practical considerations for bicarbonate loading and sports performance. Nestlé Nutrition Institute Workshop Series, 75 , 15 — Cade , R. Effects of phosphate loading on 2, 3-diphosphoglycerate and maximal oxygen uptake.

Carr , A. Effects of acute alkalosis and acidosis on performance: A meta-analysis. Sports Medicine, 41 10 , — International Journal of Sport Nutrition and Exercise Metabolism, 21 3 , — Chung , W. Effect of 10 week beta-alanine supplementation on competition and training performance in elite swimmers.

Nutrients, 4 12 , — Cook , M. New Zealand blackcurrant extract improves cycling performance and fat oxidation in cyclists. European Journal of Applied Physiology, 11 , — Cooper , R. Journal of the International Society of Sports Nutrition, 9 1 , Deminice , R.

Effects of creatine supplementation on oxidative stress and inflammatory markers after repeated-sprint exercise in humans. Nutrition, 29 9 , — Duncan , C. Chemical generation of nitric oxide in the mouth from the enterosalivary circulation of dietary nitrate.

Nature Medicine, 1 6 , — Duncan , M. Acute caffeine ingestion enhances strength performance and reduces perceived exertion and muscle pain perception during resistance exercise.

European Journal of Sport Science, 13 4 , — Effect of caffeine ingestion on torque and muscle activity during resistance exercise in men.

Folland , J. Sodium phosphate loading improves laboratory cycling time-trial performance in trained cyclists. French , C. Caffeine ingestion during exercise to exhaustion in elite distance runners.

Journal of Sports Medicine and Physical Fitness, 31 3 , — Ganio , M. Effect of caffeine on sport-specific endurance performance: A systematic review.

Goldstein , E. International society of sports nutrition position stand: Caffeine and performance. Journal of the International Society of Sports Nutrition, 7 1 , 5.

Gomez-Cabrera , M. Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance. American Journal of Clinical Nutrition, 87 1 , — Gonçalves , L.

Dispelling the myth that habitual caffeine consumption influences the performance response to acute caffeine supplementation.

Journal of Applied Physiology, 1 , — Goss , F. Trust us, you don't want to fall short on energy when you're jumping over fire pits or climbing up foot walls! Even if mud runs aren't your thing, creatine has been shown to improve performance on the playing field, as well.

Research has demonstrated improvements in power output, muscular endurance, and sprint performance in sports like soccer, hockey, rugby, and football. Looking to shave seconds off your 5K time or improve the accuracy of your passes on the soccer field?

Yes, caffeine has been suggested to help you do those things! Caffeine is a well-documented ergogenic aid in performance research, and its use in sports dates all the way back to the s.

Most of us consume caffeine because of its ability to increase alertness how else are we going to make it through a work day? Whether you like to spend your weekends on the rugby field or trying to set PRs in the gym, current research supports the benefits of caffeine in sports and high-intensity intermittent exercise.

Because many fitness activities are played outdoors in the heat and humidity or in poorly ventilated gyms, maintaining proper hydration status is critical for optimal performance.

If you're limited to water breaks, make sure to consume ounces of fluid hours prior to your activity, and another 8 ounces right before you start play.

After competition, begin rehydrating immediately, aiming to get in another ounces of fluids for every pound of bodyweight you lost via sweat. It's mile five of the Tough Mudder and you still have ditches to hurdle, ladders to climb, and walls to scale.

When pride and bragging rights between you and your buddies are at stake, you need all the help you can get! Enter beta-alanine. During high-intensity activity, your body accumulates hydrogen ions, causing a drop in your pH level, ultimately resulting in fatigue.

Beta-alanine supplementation has been shown to increase intramuscular carnosine content, thereby increasing the body's ability to buffer hydrogen ions and delay fatigue.