5th ed. Instead, available studies have used the related synthetic compound ephedrine together with caffeine and typically measured the effects 1–2 hours after a single dose [207,208]. Another systematic review and meta-analysis compared the effects of iron supplementation with no supplementation on exercise performance in women of reproductive age [149]. Teenage girls and premenopausal women are at increased risk of obtaining insufficient amounts of iron from their diets. In a position statement, AND, DoC, and ACSM state that caffeine supplementation reduces perceived fatigue and enables users to sustain exercise at the desired intensity longer [12]. Another study randomly assigned 18 young men aged 20 to 34 years to receive 120 mg/day CoQ10 for 22 days or a placebo [22]. One case report involved a morbidly obese Iranian man, age 28, who consumed 2 L/day Tribulus terrestris water for 2 days before being hospitalized with seizures, severe weakness in the legs, malaise, and poor appetite [195]. Safety: The only toxicity studies of Tribulus terrestris were conducted in animals, where unspecified high intakes led to severe heart, liver, and kidney damage [190]. Nestlé Nutrition Institute Workshop Series. The preponderance of research to date suggests that exercise-induced reactive oxygen species and nitric oxide are beneficial. Some research-derived data is available on these ingredients on which to base a judgment about their potential value to aid exercise and athletic performance. The authors of the most recent review of studies on beta-alanine's effects on exercise concluded that supplementation has a statistically significant and positive effect on performance (including in both isolated-limb and whole-body exercises), especially in protocols lasting 30 seconds to 10 minutes [58]. Athletes engaging in endurance activities lasting more than an hour or performed in extreme environments (e.g., hot temperatures or high altitudes) might need to replace lost fluids and electrolytes and consume additional carbohydrates for energy. Burd NA, Phillips SM. Operation Supplement Safety. The labels on tart-cherry juice and concentrate products do not usually indicate that they are dietary supplements, although the labels on products containing encapsulated tart-cherry powder do. Clin J Sport Med 2006;16:68-71. In fact, they can adversely affect some measures of exercise and athletic performance. J Sports Med 2013;4:53-61. Research on the ability of supplemental arginine to raise HGH and IGF-1 serum concentrations also has had conflicting findings. 2017;14:18. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2011. N Z Med J 2012;125:80-6. Nutr Res Rev. Am J Clin Nutr 2006;83:905-11. It is thought that "bicarbonate loading" enhances disposal of hydrogen ions that accumulate and efflux from working muscles as they generate energy in the form of ATP via anaerobic glycolysis from high-intensity exercise, thereby reducing the metabolic acidosis that contributes to fatigue [180,181]. [, Chun OK, Chung SJ, Song WO. Eur J Haematol 2012;90:10-5. The same research group conducted another trial using the same doses of vitamins C and E in 32 young men and women who followed a strength-training program for 10 weeks. This is a fact sheet intended for health professionals. Free Radic Biol Med 2016;98:144-58. The FDA regulates dietary supplements for exercise and athletic performance in accordance with the Dietary Supplement Health and Education Act of 1994 [209]. For example, quercetin might increase the number of mitochondria in muscle, reduce oxidative stress, decrease inflammation, and improve endothelial function (blood flow) [170,171]. B-hydroxy-B-methylbutyrate (HMB) supplementation in humans is safe and may decrease cardiovascular risk factors. Aerobic exercise leads to more modest protein accumulation in working muscle, primarily in the mitochondria, which enhances oxidative capacity (oxygen use) for future workouts [155,156]. [, Malm C, Svensson M, Ekblom B, Sjodin B. Boca Raton FL: CRC Press/Taylor & Francis. Safety: In the studies described above, the glutamine had no reported side effects. Safety: Studies have not identified any safety concerns with the consumption of beetroot juice in moderate amounts (about 2 cups/day) for several weeks. Carnosine is present in animal-based foods, such as beef and pork. Another 20 were randomized to receive either 300 mg/day androstenedione or a placebo for 6 of 8 weeks while undergoing resistance-training and muscle-strengthening exercises [199]. Beetroot juice and exercise: pharmacodynamic and dose-response relationships. Furthermore, in predominantly aerobic exercise lasting more than 150 seconds, the body relies on oxidative phosphorylation as the primary energy source, a metabolic pathway that does not require creatine [114]. Evidence and knowledge gaps for the association between energy drink use and high-risk behaviors among adolescents and young adults. [, Jacobson IG, Horton JL, Smith B, Wells TS, Boyko EJ, Lieberman HR, Ryan MAK, Smith TC. Bellinger PM. [, Sleivert G, Burke V, Palmer C, Walmsley A, Gerrard D, Haines S, Littlejohn R. The effects of deer antler velvet extract or powder supplementation on aerobic power, erythropoiesis, and muscular strength and endurance characteristics. Each section concludes with information and advice from expert sources, when available, on use of the ingredient as an ergogenic aid. The American Academy of Pediatrics warns that caffeine-containing energy drinks in particular "have no place in the diets of children or adolescents" and are not suitable for use during routine physical activity [101]. Protein supplements … J Physiol 2016;594:5135-47. 2014 Aug;24(4):437-49. doi: 10.1123/ijsnem.2014-0017. J Strength Cond Res 2011;25(12):3461-71. Evidence-based evaluation of potential benefits and safety of beta-alanine supplementation for military personnel. In: Tipton KD, van Loon LJC, eds. Because the research results are conflicting, the activities and individuals most likely to benefit from sodium bicarbonate supplementation in real-world conditions is not clear. Safety: The authors of the short-term studies investigating ribose as a potential ergogenic aid have not reported any safety concerns. Recreationally active individuals, in particular, might find the supplements to be ergogenic for one exercise session but not another. The RDA is 8 mg for men and 18 mg for women aged 50 and younger, and 8 mg for older adults of both sexes. In one example, a study randomized 14 healthy, resistance-trained men (aged 19–29 years) to receive 25 g creatine monohydrate or a placebo for 6–7 days [116]. [, Hidaka T, Fujii K, Funahashi I, Fukutomi N, Hosoe K. Safety assessment of coenzyme Q10 (CoQ10). It is therefore difficult to predict what, if any, benefits an exercising individual might experience from consuming HMB. Supplementation with creatine over weeks or months helps training adaptations to structured, increased workloads over time. Panax ginseng in randomised controlled trials: a systematic review. [, Dong J-Y, Qin L-Q, Zhang Z, Zhao Y, Wang J, Arigoni F, Zhang W. Effect of oral L-arginine supplementation on blood pressure: A meta-analysis of randomized, double-blind, placebo-controlled trials. Sports-supplement dangers. Exercise increases intramuscular protein oxidation and breakdown, after which muscle-protein synthesis increases for up to a day or two [155]. The BCAAs, especially leucine, might also stimulate protein synthesis in exercised muscle [72,76]. Clin Nutr 2015;34:976-85. Compared with those taking the placebo, participants taking the creatine improved their performance in both 100- meter sprints and six intermittent 60 m sprints. However, oral consumption of carnosine is an inefficient method of increasing muscle carnosine concentrations because the dipeptide is digested into its constituent amino acids. Am J Sports Med 2010;38:133-40. [, Hoffman JR, Ratamess NA, Kang J, Rashti SL, Faigenbaum AD. Beetroot is available as a juice or juice concentrate and in powdered form; the amount of nitrate can vary considerably among products. Single and combined effects of betroot crystals and sodium bicarbonate on 4-km cycling time trial performance. The effect of creatine supplementation on muscle strength and body composition during off-season training in female soccer players. However, there is little research-based support for this benefit [140,141]. [, Baguet A, Reyngoudt H, Pottier A, Everaert I, Callens S, Achten E, Derave W. Carnosing loading and washout in human skeletal muscles. Chicago, IL: Academy of Nutrition and Dietetics; 2012:36-57. As with DMAA, FDA had never approved this stimulant as a new dietary ingredient. Some athletes use glutamine supplements in the hope that they will attenuate exercise-induced immune impairment and reduce their risk of developing upper respiratory tract infections. In: Rosenbloom CA and Coleman EJ, eds. At the top of the list of popular herbs are echinacea and ginseng, whereas garlic, St. John’s wort, … A typical protocol for creatine supplementation in adults, regardless of sex or body size, consists of a loading phase for 5–7 days, when users consume 20 g/day creatine monohydrate in four portions of 5 g, followed by a maintenance phase of 3–5 g/day [112-114]. Soy protein lacks the EAA methionine and might lose some cysteine and lysine in processing; rice protein lacks the EAA isoleucine [166]. The supplements used by male and female athletes are similar, except that a larger proportion of women use iron and a larger proportion of men take vitamin E, protein, and creatine. Taking more, however, is unlikely to improve performance further and increases the risk of side effects. Protein ingestion before sleep increases muscle mass and strength gains during prolonged resistance-type exercise training in healthy young men. Caffeine. [, Braakhuis AJ, Hopkins WG. Many athletes use dietary supplements as part of their regular training or competition routine, including about 85% of elite track and field athletes. In Coates PM, Betz JM, Blackman MR, Cragg GM, Levine M, Moss J, White JD, eds. [, Zajac A, Poprzecki S, Zebrowska A, Chalimoniuk M, Langfort J. Arginine and ornithine supplementation increases growth hormone and insulin-like growth factor-1 serum levels after heavy-resistance exercise in strength-trained athletes. The effects of beta-alanine supplementation on performance: a systematic review of the literature. BioFactors 2008;32:199-208. [, May DC, Jarboe CH, VanBakel AB, Williams WM. [, Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, Candow DG, Kleiner SM, Almada AL, Lopez HL. Please enable it to take advantage of the complete set of features! Implications for use: In a position statement, the Academy of Nutrition and Dietetics (AND), the Dietitians of Canada (DoC), and the American College of Sports Medicine (ACSM) state that nitrate sources, such as beetroot juice, enhance exercise tolerance and economy and they improve endurance exercise performance in recreational athletes [12]. [, Torpy JM, Livingston EH. Vol 75. Clipboard, Search History, and several other advanced features are temporarily unavailable. The labels on beetroot juice and concentrate usually indicate that these products are foods and not dietary supplements. The National Collegiate Athletic Association and the World Anti-Doping Agency ban the use of DHEA [105,128]. Protein increases urinary calcium excretion, but this appears to have no consequence for long-term bone health [165] and, in any event, is easily compensated for by the consumption of slightly more calcium. Caffeine also appears to reduce perceived pain and exertion [13,85]. In the 18 studies that compared arginine alone with a placebo, the most common doses were 2–10 g/day as a single dose and up to 20 g/day divided into three doses. J Int Soc Sports Nutr 2015;12:38. Studies provide little consistent evidence of a relationship between the dose of beta-alanine and performance effect [51,58]. Int J Sport Nutr Exerc Metab 2017;27:255-63. The quality of many studies is limited by their small samples and short durations, use of performance tests that do not simulate real-world conditions or are unreliable or irrelevant, and poor control of confounding variables [12]. One systematic review and meta-analysis to determine whether iron treatments (provided orally or by injection) improved iron status and aerobic capacity in iron-deficient but non- anemic endurance athletes identified 19 studies involving 80 men and 363 women with a mean age of 22 years. However, FDA notes that products marketed as dietary supplements for bodybuilding are among those most often adulterated with undeclared or deceptively labeled ingredients, such as synthetic anabolic steroids or prescription medications [212]. However, other evidence shows no habituation effect of caffeine consumption on performance [92]. [, Lidder S, Webb AJ. In almost all cases, the studies found that Panax ginseng in various doses and preparations had no ergogenic effect on such measures as peak power output, time to exhaustion, perceived exertion, recovery from intense activity, oxygen consumption, or heart rate [132,134-136]. Many study findings suggest that supplementation with sodium bicarbonate is most likely to improve the performance of trained athletes [181,182]. Muscle protein synthesis leading to increases in strength and muscle mass appears to be optimal with the consumption of high-quality protein (providing about 10 g EAAs) within 0–2 hours after exercise, in the early recovery phase [12]. The body also synthesizes arginine (from citrulline), mainly in the kidneys. However, it advises caution for those obtaining high protein intakes from foods and supplements because of the limited data on their potential adverse effects. Safety: Athletes can safely obtain recommended intakes of iron by consuming a healthy diet containing iron-rich foods and by taking an iron-containing dietary supplement as needed. Sports supplements are pills, powders, or drinks used to build muscle, lose weight, or improve endurance. Cimetidine (Tagamet HB, used to treat duodenal ulcers) can slow the rate of caffeine clearance from the body and thereby increase the risk of adverse effects from caffeine consumption [219]. [. Determination of the tolerable upper intake level of leucine in acute dietary studies in young men. In these studies, performance improvement ranged from a decrease of 0.7% to an increase of 17.3%, suggesting that the caffeine was very helpful to some participants but slightly impaired performance in others. McClung JP, Gaffney-Stomberg E, Lee JJ. The influence of oral L-glutamine supplementation on muscle strength recovery and soreness following unilateral knee extension eccentric exercise. Join the ODS Email List, Dietary Supplements for Exercise and Athletic Performance. Creatine supplementation may reduce the range of motion of various parts of the body (such as the shoulders, ankles, and lower legs) and lead to muscle stiffness and resistance to stretching [114]. [, Peveler WW, Bishop PA, Whitehorn EJ. For an individual weighing 154 pounds (70 kg), this dose is equivalent to 210–420 mg caffeine. There are well-documented roles for creatine, caffeine, and alkalinizing agents in enhancing performance in high-intensity exercise, although much of the evidence does not relate to specific athletic events. Brown GA, Vukovich M, King DS. Implications for use: Caffeine is easily and rapidly absorbed, even from the buccal membranes in the mouth, and is distributed throughout the body and brain. Many exercise and athletic-performance dietary supplements in the marketplace contain multiple ingredients (especially those marketed for muscle growth and strength). Pharmacogenetics 1993;3:302-11. One review of studies of the effects of Siberian ginseng on endurance performance found that the five studies with the most rigorous research protocols (with a total of 55 men and 24 women) showed no effect of supplementation for up to 6 weeks on exercise performed for up to 120 minutes [133]. The ISSN recommends that healthy adults interested in using HMB supplements take 1–2 g HMB-Ca 60 to 120 minutes before exercise or 1–2 g HMB-FA 30 to 60 minutes before exercise [63]. Creatine is one of the most popular sports supplement these days and it is consumed by 25–40% of young athletes [ 7, 10, 12, 19 ]. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice.