• Ergogenic Aids

There are many methods used to help boost athletic performance. Anything that makes your strength, speed, or endurance better is called an ergogenic aid. Some are illegal and can be harmful, such as stimulants, steroids, and human growth hormone. However, some natural therapies may be helpful.

Natural Therapies

Likely Effective

Iron may be helpful for athletes who are iron-deficient but not anemic. The best source of iron is through diet. A1-A3

May Be Effective

These therapies may provide benefit:

  • Betaine (trimethylglycine) is a microorganism found in plants, animals, and foods. It may improve how muscles use oxygen. B1-B3
  • Bovine colostrum is the first breast fluid from a cow. It may improve lean body mass, repeat exercise, and sprinting, but not endurance. C1-C3
  • Caffeine is a natural stimulant found in coffee, tea, and cocao plants. It may boosts performance in short, intense bursts. D1-D6
  • Carnitine is a natural substance that the body uses to process fats and make energy. It may help with muscle metabolism. F1-F4
  • Creatine is a compound the body makes and uses to store energy. It may help with repeated short bursts of high-intensity activity, but not with endurance. E1-E5
  • Hydroxymethyl butyrate is a compound the body makes to help break down amino acids. It may increase muscle mass, but it does not boost performance. G1-G2
  • Kinesiology tape is an adhesive, elastic cotton strip used to treat injuries. It may increase muscle strength, which may help performance. H1-H3
  • N-acetylcysteine is the supplement form of the amino acid cysteine. It may help with endurance, but may only be useful for people with low levels of gluthathione. I1-I3
  • Phosphatidylserine is a fatty substance the body makes that protects all cells and helps with clotting. It may increases time to exhaustion in trained athletes and may help with sport-specific performance. J1-J3
  • Rhodiola rosea is a perennial flowering plant. It may be useful for endurance athletes. K1-K5

Unlikely to Be Effective

These therapies are unlikely to provide benefit:

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Herbs and Supplements to Be Used With Caution

Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse, such as:

  • Iron can be toxic when taken in high doses. Doing so can lead to organ damage and death. Several common medicines may interfere with iron absorption.
  • Carnitine may interfere with antiseizure and thyroid medicines.
  • N-acetylcysteine may cause side effects that may increase with dosage. This may include nausea, vomiting, fever, or sore throat.



REFA1 Friedmann B, Weller E, et al. Effects of iron repletion on blood volume and performance capacity in young athletes. Med Sci Sports Exerc. 2001;33(5):741-746.

REFA2 Brutsaert TD, Hernandez-Cordero S, et al. Iron supplementation improves progressive fatigue resistance during dynamic knee extensor exercise in iron-depleted, nonanemic women. Am J Clin Nutr. 2003;77(2):441-448.

REFA3 Alaunyte I, Stojceska V, et al. Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance. J Int Soc Sports Nutr. 2015;12:38.

Betaine (trimethylglycine)

REFB1 Lee EC, Maresh CM, et al. Ergogenic effects of betaine supplementation on strength and power performance. J Int Soc Sports Nutr. 2010;7:27.

REFB2 Hoffman JR, Ratamess NA, et al. Effect of 15 days of betaine ingestion on concentric and eccentric force outputs during isokinetic exercise. J Strength Cond Res. 2011;25(8):2235-2241.

REFB3 Trepanowski JF, Farney TM, et al. The effects of chronic betaine supplementation on exercise performance, skeletal muscle oxygen saturation and associated biochemical parameters in resistance trained men. J Strength Cond Res. 2011;25(12):3461-3471.

Bovine Colostrum

REFC1 Antonio J, Sanders MS, et al. D. The effects of bovine colostrum supplementation on body composition and exercise performance in active men and women. Nutrition. 2001;17(3):243-247.

REFC2 Buckley JD1, Abbott MJ, et al. Bovine colostrum supplementation during endurance running training improves recovery, but not performance. J Sci Med Sport. 2002;5(2):65-79.

REFC3 Hofman Z, Smeets R, et al. The effect of bovine colostrum supplementation on exercise performance in elite field hockey players. Int J Sport Nutr Exerc Metab. 2002;12(4):461-469.


REFD1 Souza DB, Duncan M, et al. Acute caffeine intake improves lower body resistance exercise performance with blood flow restriction. Int J Sports Physiol Perform. 2018:1-22.

REFD2 Pires FO, Dos Anjos CAS, et al. Caffeine and placebo improved maximal exercise performance despite unchanged motor cortex activation and greater prefrontal cortex deoxygenation. Front Physiol. 2018;9:1144.

REFD3 Glaister M, Towey C, et al. Caffeine and sprint cycling performance: effects of torque factor and sprint duration. Int J Sports Physiol Perform. 2018:1-19.

REFD4 Ellis M, Noon M, et al. Low Doses of Caffeine: Enhancement of Physical Performance in Elite Adolescent Male Soccer Players. Int J Sports Physiol Perform. 2019 May 1;14(5):569-575.

REFD5 Salinero JJ, Lara B1, et al. Effects of acute ingestion of caffeine on team sports performance: a systematic review and meta-analysis. Res Sports Med. 2018:1-19.

REFD6 Ellis M, Noon M, et al. Low Doses of Caffeine: Enhancement of Physical Performance in Elite Adolescent Male Soccer Players. Int J Sports Physiol Perform. 2019 May 1;14(5):569-575.


REFE1 Branch JD. Effect of creatine supplementation on body composition and performance: a meta-analysis. Int J Sport Nutr Exerc Metab. 2003;13(2):198-226.

REFE2 Theodorou AS, Havenetidis K, et al. Effects of acute creatine loading with or without carbohydrate on repeated bouts of maximal swimming in high-performance swimmers. J Strength Cond Res. 2005;19(2):265-269.

REFE3 Cornish SM, Chilibeck PD, et al. The effect of creatine monohydrate supplementation on sprint skating in ice-hockey players. J Sports Med Phys Fitness. 2006;46(1):90-98.

REFE4 Glaister M, Lockey RA, et al. Creatine supplementation and multiple sprint running performance. J Strength Cond Res. 2006;20(2):273-277.

REFE5 Pluim BM, Ferrauti A, et al. The effects of creatine supplementation on selected factors of tennis specific training. J Int Soc Sports Nutr. 2017;14:18.


REFF1 Smith WA, Fry AC, et al. Effect of glycine propionyl-L-carnitine on aerobic and anaerobic exercise performance. Int J Sport Nutr Exerc Metab. 2008;18(1):19-36.

REFF2 Wall BT, Stephens FB, et al. Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. J Physiol. 2011;589(Pt 4):963-973.

REFF3 Orer GE, Guzel NA. The effects of acute L-carnitine supplementation on endurance performance of athletes. J Strength Cond Res. 2014;28(2):514-519.

REFF4 Burrus BM, Moscicki BM, et al. The effect of acute L-carnitine and carbohydrate intake on cycling performance. Int J Exerc Sci. 2018;11(2):404-416.

Hydroxymethlyl Butyrate

REFG1 Portal S, Zadik Z, et al. The effect of HMB supplementation on body composition, fitness, hormonal and inflammatory mediators in elite adolescent volleyball players: a prospective randomized, double-blind, placebo-controlled study. Eur J Appl Physiol. 2011;111(9):2261-2269.

REFG2 Sanchez-Martinez J, Santos-Lozano A, et al. Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trials. J Sci Med Sport. 2018;21(7):727-735.

Kinesiology Tape

REFH1 Huang CY, Hsieh TH, et al. Effect of the Kinesio tape to muscle activity and vertical jump performance in healthy inactive people. Biomed Eng Online. 2011;10:70.

REFH2 Reneker JC, Latham L, et al. Effectiveness of kinesiology tape on sports performance abilities in athletes: A systematic review. Phys Ther Sport. 2018;31:83-98.

REFH3 Choi IR, Lee JH. Effect of kinesiology tape application direction on quadriceps strength. Medicine (Baltimore). 2018 Jun;97(24):e11038.


REFI1 Slattery KM, Dascombe B, et al. Effect of N-acetylcysteine on cycling performance after intensified training. Med Sci Sports Exerc. 2014;46(6):1114-1123.

REFI2 Rhodes K, Braakhuis A. Performance and side effects for supplementation with n-acetylcysteine: a systematic review and meta-analysis. Sports Med. 2017;47(8):1619-1636.

REFI3 Paschalis V, Theodorou AA, et al. N-acetylcysteine supplementation increases exercise performance and reduces oxidative stress only in individuals with low levels of glutathione. Free Radic Biol Med. 2018;115:288-297.


REFJ1 Kingsley MI, Wadsworth D, et al. Effects of phosphatidylserine on oxidative stress following intermittent running. Med Sci Sports Exerc. 2005;37(8):1300-1306.

REFJ2 Kingsley MI, Miller M, et al. Effects of phosphatidylserine on exercise capacity during cycling in active males. Med Sci Sports Exerc. 2006;38(1):64-71.

REFJ3 Jäger R, Purpura M, et al. The effect of phosphatidylserine on golf performance. J Int Soc Sports Nutr. 2007;4:23.

Rhodiola Rosea

REFK1 Earnest CP, Morss GM, et al. Effects of a commercial herbal-based formula on exercise performance in cyclists. Med Sci Sports Exerc. 2004;36(3):504-509.

REFK2 De Bock K, Eijnde BO, et al. Acute Rhodiola rosea intake can improve endurance exercise performance. Int J Sport Nutr Exerc Metab. 2004;14(3):298-307.

REFK3 Colson SN, Wyatt FB, et al. Cordyceps sinensis- and Rhodiola rosea-based supplementation in male cyclists and its effect on muscle tissue oxygen saturation. J Strength Cond Res. 2005;19(2):358-363.

REFK4 Parisi A, Tranchita E, et al. Effects of chronic Rhodiola Rosea supplementation on sport performance and antioxidant capacity in trained male: preliminary results. J Sports Med Phys Fitness. 2010;50(1):57-63.

REFK5 Ballmann CG, Maze SB, et al. Effects of short-term Rhodiola Rosea (Golden Root Extract) supplementation on anaerobic exercise performance. J Sports Sci. 2018:1-6.

Branched-chain Amino Acids

REFL1 Salinas-García ME, Martínez-Sanz JM, et al. [Effects of branched amino acids in endurance sports: a review]. Nutr Hosp. 2014;31(2):577-589.


REFM1 Bach HV, Kim J, et al. Efficacy of ginseng supplements on fatigue and physical performance: a meta-analysis. J Korean Med Sci. 2016;31(12):1879-1886.

Low Glycemic Index Meal

REFN1 Burdon CA, Spronk I, et al. Effect of glycemic index of a pre-exercise meal on endurance exercise performance: a systematic review and meta-analysis. Sports Med. 2017;47(6):1087-1101.


REFO1 Dunne L, Worley S, et al. Ribose versus dextrose supplementation, association with rowing performance: a double-blind study. Clin J Sport Med. 2006;16(1):68-71. O2. Seifert JG, Brumet A, St Cyr JA. The influence of D-ribose ingestion and fitness level on performance and recovery. J Int Soc Sports Nutr. 2017;14:47.

Tibulus Terrestris

REFP1 Qureshi A, Naughton DP, et al. A systematic review on the herbal extract Tribulus terrestris and the roots of its putative aphrodisiac and performance enhancing effect. J Diet Suppl. 2014;11(1):64-79.

Revision Information

  • Reviewer: EBSCO NAT Review Board Eric Hurwitz, DC
  • Review Date: 12/2019
  • Update Date: 06/22/2020