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Information about SportsNutrition2007

Published on January 24, 2008

Author: Saverio


Sports Nutrition, Nutritional Supplements & Anabolic Steroids:  Sports Nutrition, Nutritional Supplements & Anabolic Steroids Sean T. Bryan, MD, FAAFP Assistant Clinical Professor of Family Medicine, Medical College of Georgia and Mercer University School of Medicine Program Director, SW GA Family Medicine Residency Fellowship Director, SW GA Sports Medicine Program Phoebe Putney Memorial Hospital Albany, GA 2007 Sports Medicine Seminar for Coaches Overview:  Overview Increase awareness that nutrition can affect athletic performance Discuss current nutritional recommendations for athletes Review the 1994 Dietary Supplement Health & Education Act Definition of a supplement Impact of this legislation Overview:  Overview Discuss specific nutritional supplements commonly used by athletes Do they work? Are they safe? Review the 2004 Anabolic Steroid Control Act Definition of an anabolic steroid Impact of this legislation Help coaches answer questions and address concerns of athletes and parents Performance Influencing Factors :  Performance Influencing Factors Genetics Training & conditioning Nutrition Determinants of the Athlete’s Energy Requirements:  Determinants of the Athlete’s Energy Requirements During intense exercise Glycogen stored in muscles and liver is predominant fuel source During prolonged exercise Fat stores are predominant fuel source Fitness level of the athlete Well trained endurance athletes burn fat more efficiently thus sparing limited glycogen stores Formula for Estimating the Body’s Calorie Requirements:  Formula for Estimating the Body’s Calorie Requirements Sedentary person Weight (kg) x 25 Moderately active person Weight (kg) x 30 Active person (endurance athlete) Weight (kg) x 40 Underweight person Weight (kg) x 45 Recommendations:  Recommendations Carbohydrate intake Carbohydrate loading Protein intake Fat intake Pre-exercise meal NOT “pre-game meal” Carbohydrates:  Carbohydrates Non-essential nutrient (human body can make sugar) Simple (sugars) and Complex (starches) Major fuel source for exercising muscle Athletes should ingest 6 to10 gm/kg/day 60 to 70% of total calories should come from carbohydrates Complex carbohydrates (starches) are preferable During exercise Athletes should consume 25 to 30 gm of carbohydrate for every 30 minutes of exercise Athletes should drink 6 to 8 ounces of water or sports drink for every 10 to 15 minutes of exercise Carbohydrates:  Carbohydrates After exercise Athletes should consume 1.0 to 1.5 gm/kg immediately post exercise and again one hour later To replace muscle glycogen stores To prevent gradual depletion of muscle glycogen stores over time caused by repetitive daily bouts of heavy exercise To decrease muscle breakdown Why Complex Carbohydrates?:  Why Complex Carbohydrates? Compared to sugars, starches are better as a pre-exercise meal because they: Increase muscle glycogen stores better Improve performance and delay fatigue Lead to lower blood sugar and insulin levels Cause less stomach upset and indigestion Promote faster stomach emptying Provide other beneficial nutrients Fiber, vitamins and minerals Pre-exercise Meal:  Pre-exercise Meal Importance Less hunger before and during exercise Maintains optimum glycogen stores Recommendations Emphasize complex carbohydrates (starches) 1 to 4 gm/kg about 1 to 4 hours prior to event Consume less closer to event Avoid high fat and high protein foods Slower gastric emptying can cause stomach upset Avoid high fiber or gas forming foods Can lead to crampy abdominal pain Carbohydrate Loading:  Carbohydrate Loading Increases the body’s pre-exercise glycogen stores by 50 to 100% Benefits endurance athletes who compete for longer than 90 minutes Can increase endurance up to 20% Can increase performance by 2 to 3% Carbohydrate Loading: One Example:  Carbohydrate Loading: One Example Days prior to event Exercise duration Carbohydrate intake 6 90 minutes 5 gm/kg/day 5 40 minutes 5 gm/kg/day 4 40 minutes 5 gm/kg/day 3 20 minutes 10 gm/kg/day 2 20 minutes 10 gm/kg/day 1 rest 10 gm/kg/day Protein:  Protein Athletes require more protein than non-athletes 12 to 18% of total calories should come from protein Protein intake should be tailored to type of training 1.2 to 1.4 gm/kg/day recommended for endurance athletes 1.7 to 1.8 gm/kg/day recommended for strength athletes Protein:  Protein Average American diet provides 1.4 gm/kg/day Adequate calorie intake is just as important as adequate protein intake for building muscles Too much protein intake can be bad Excess protein calories are stored as fat Excess protein intake can contribute to dehydration and possibly renal problems Fat:  Fat Major source of energy 25 to 30% of total calories should come from fat Less than 10% of total calories should come from saturated fats Cholesterol intake should be < 300 mg/day Average American diet provides 37% of total calories from fat Nutritional Supplements:  Nutritional Supplements 1994 Dietary Supplement Health and Education Act Definition of a supplement Any product that contains vitamins, minerals, amino acids, herbs, botanicals or a concentrate, metabolite, constituent, extract or combination of any of these ingredients Removed dietary supplements from FDA regulation on the front end FDA must prove a supplement is dangerous before its sale can be prohibited Nutritional Supplements:  Nutritional Supplements 1994 Dietary Supplement Health and Education Act Manufacturers do not have to provide scientific proof of claims Manufacturers cannot state product is meant to diagnose, treat, prevent or cure a disease but can make indirect suggestions Created a multi-billion dollar industry that continues to grow rapidly Vitamins and Minerals:  Vitamins and Minerals Essential nutrients Human body needs these to produce energy No evidence in U.S. studies that taking vitamin and mineral supplements improves athletic performance Being deficient in vitamins or minerals is rare in the U.S. compared to the rest of the world A few studies outside U.S. showed an effect Did population studied have some baseline deficiency treated with these supplements? Vegetarian athletes are at risk for being deficient in vitamins B12, D, riboflavin, iron, zinc and calcium Athletes who are strict vegetarians should take a multivitamin to prevent deficiencies and a calcium supplement (1000 mg/day) to help prevent bone loss Vitamins and Minerals:  Vitamins and Minerals Specific vitamins and minerals studied Vitamin A and Vitamin D No evidence of increased performance May have toxic effects at high doses Vitamin E No evidence of increased performance Toxic effects are rare Vitamin C Anti-oxidant effect may help decrease exercise related muscle soreness No effect on strength Possible toxic effects at high doses Vitamins and Minerals:  Vitamins and Minerals Specific vitamins and minerals studied Vitamin B6 No evidence of increased performance Toxic over 200 mg/day (nervous system side effects) Other anti-oxidants (Betacarotene, Bioflavinoids, Copper, Cysteine and Glutathione) May help to protect against exercise induced muscle damage Study results are conflicting Should not exceed 100% U.S. RDA of anti-oxidants Buyer beware! Some supplements have been found to contain up to 3000% of U.S. RDA for vitamins and minerals Creatine:  Creatine Chemical name: Creatine-Monohydrate Naturally available in meat and fish NCAA study found creatine supplements used by 12% of college athletes A subsequent survey of high school athletes showed similar usage rates Mechanism of action Unknown Energy source for exercising muscle? Creatine:  Creatine Does supplementation: Increase muscle mass? Increase strength? Increase athletic performance? Is supplementation safe? Concerns about: Increased muscle cramping Increased risk of muscle injury Increased risk of heat intolerance Increased risk of dehydration Increased risk of hepatic and/or renal disease Creatine:  Creatine 9 studies showing (+) effects in healthy subjects Increased high intensity, intermittent exercise performance in squash players Increased cell hydration status and performance variables in Division I college football players more than training alone Augments repeated sprint cycle performance in hot environment without altering thermoregulatory responses Increases indices of high intensity exercise performance for both males and females Increased capacity of human muscle to perform work during alternating intensity contraction Creatine:  Creatine 9 Studies showing (+) effects (continued) Ergogenic effect in elite ice hockey players Loading improves intermittent sprint capacity at end of endurance exercise to fatigue Adding creatine to glucose, taurine and electrolyte supplement promoted greater gains in fat and bone free mass, isotonic lifting volume and sprint performance during intense resistance and agility training Helped to prolong time maximal rate of power output could be maintained Creatine:  Creatine 4 Studies with no effect in healthy subjects Did not positively influence isometric strength in untrained (sedentary) males Did not increase performance or training volume over placebo in rowers that performed a high intensity rowing and strength program No statistically significant difference in strength or fat free mass gains after a resistance exercise training program compared with post exercise protein supplementation Small placebo controlled trial in elite swimmers over 23 to 28 weeks - no statistically significant difference in maximal sprint test performance between groups Creatine:  Creatine 5 Studies looking at safety in healthy subjects Retrospective study of 26 athletes who reported taking creatine between 0.8 and 4 years - blood chemistries including liver and kidney function were all normal Neither 12 weeks of supplementation with training nor training alone had any effect on serum cholesterol, HDL, LDL, TG or creatinine levels Supplementation for 5 days had no effect on BP, serum creatinine, estimated creatinine clearance or plasma CK Oral supplementation for 5 days had no effect on GFR, total protein or albumin excretion rates and all remained normal Oral supplementation for 7 days did not increase incidence of symptoms, compromise hydration or compromise thermoregulation in dehydrated trained men exercising in the heat Creatine:  Creatine My opinion about creatine In combination with high intensity strength training, creatine increases strength during high intensity intermittent exercise 7 to 8% more than training alone Creatine increases performance in sports involving or requiring high intensity intermittent bursts of strength Jumping, sprinting, cycling, hitting a ball Creatine does not help endurance athletes Long term effects (use > 4 years) are not known! Dosing Loading: 20 to 30 gm/day for 5 to 7 days Maintenance: 3 to 5 gm/day 10 to 15 gm/day Ephedra or MaHuang:  Ephedra or MaHuang Herbal forms of the stimulant ephedrine 80 confirmed deaths related to ephedra use Experts suspect many more unconfirmed deaths Adverse effects High blood pressure (most common) Palpitations and increased heart rate Seizure Thermoregulatory dysfunction Stroke Heart attack Sudden death Vasculitis Allergic myocarditis (one case report) Acute hepatitis (one case report) Ephedra or MaHuang:  Ephedra or MaHuang Following the deaths of two pro athletes (Korey Stringer & Steve Bechler), FDA banned sale of Ephedra as a nutritional supplement Since this time, manufacturers have started substituting other stimulants “Ephedra Free” does NOT equal “safe”! Citrus Aurantium Orange extract Chemical structure very similar to ephedrine Anabolic Steroid Precursors:  Anabolic Steroid Precursors Dehydroepiandrosterone (DHEA) and Androstenedione (“Andro”) Chemicals that can be converted into testosterone in human biochemical pathways Naturally available in wild yams An early study done by a manufacturer of these products showed no significant increase in blood levels of testosterone Study looked at lower doses of these supplements than are usually taken and did not measure ratio of testosterone to epitestosterone (T:E ratio) Anabolic Steroid Precursors:  Anabolic Steroid Precursors Subsequent independent scientific studies DHEA Does not seem to have much if any effect on fat-free body mass and strength Androstenedione Causes a temporary increase in testosterone levels Has no effect on body’s ability to make protein Does not seem to have any effect on strength No long term effect on blood testosterone levels Chronic use causes increase in estrogen levels Anabolic Steroid Precursors:  Anabolic Steroid Precursors Potential adverse effects May cause liver damage In females Can cause hirsutism May increase risk of uterus cancer In males Can cause gynecomastia May increase risk of prostate cancer May have legal implications May keep you out of MLB Hall of Fame Anabolic Steroids AND Anabolic Steroid Precursors:  Anabolic Steroids AND Anabolic Steroid Precursors Are banned and tested for by the USOC, IOC, NCAA, NFL, NBA and MLB NHL has no official policy and does not perform testing You can be disqualified from participating in college sports if you test positive for a substance banned by the NCAA Whether or not you knew it was banned Whether or not the product was mislabeled Buyer Beware!:  Buyer Beware! IOC funded study by Shanzer (Germany) from 10/00 to 11/01 Analyzed 634 products labeled as non-hormonal nutritional supplements from 13 countries and 215 different suppliers 94 products (14.8%) were found to be “positive supplements” (contained anabolic steroid precursors not declared on the label) Anabolic androgenic steroid concentrations ranged from 0.01 to 190 mcg/gm of supplement 23 products contained steroid precursors of nandrolone and testosterone 64 products contained steroid precursors of testosterone only 7 products contained steroid precursors of nandrolone only Percentage of positive supplements per country 25.8% of products bought in Netherlands 22.7% of products bought in Austria 18.8% of products bought in UK 18.8% of products bought in US (45 positive out of 240 tested) Anabolic Steroid Control Act of 2004:  Anabolic Steroid Control Act of 2004 Signed into federal law on October 22, 2004 Amends the Anabolic Steroid Control Act of 1990 Modifies the definition of anabolic steroids to include tetrahydrogestrinone (THG), androstenedione, and specified related chemicals Directs the U.S. Sentencing Commission (USSC) to review federal sentencing guidelines with respect to anabolic steroid-related offenses Amends guidelines to provide for increased penalties Support for passing this law fueled by BALCO scandal Anabolic Steroid Control Act of 2004:  Anabolic Steroid Control Act of 2004 Authorizes the Attorney General to exempt from regulation any compound, mixture, or preparation containing an anabolic steroid that does not present a significant abuse potential Directs the Secretary of Health and Human Services to award grants for science-based education programs in elementary and secondary schools to highlight the harmful effects of anabolic steroids and to ensure that the National Survey on Drug Use and Health (NSDUH) includes questions concerning the use of these drugs. Source: Library of Congress 749*:  749* Conclusions:  Conclusions Nutrition plays an important role in an athlete’s ability to perform Proper nutrition in combination with sound and proven training techniques can help athletes to maximize their genetic abilities Creatine Has been shown to increase strength during intermittent high intensity exercise Has not been shown to improve performance in endurance athletes Safety of long-term use remains unknown Certain nutritional supplements have not demonstrated any performance benefit Conclusions:  Conclusions Certain nutritional supplements can have potentially dangerous side effects Further legislation is needed to address the dangers of some nutritional supplements Health professionals in the community need to be resources of accurate information for athletes, parents and coaches Physicians Nurse practitioners and physician assistants Physical therapists Athletic trainers School nurses Dieticians Questions?:  Questions? Thank You! References:  References Bemben MG, Bemben DA, Loftiss DD, Knehans AW. Creatine supplementation during resistance training in college football athletes. Med Sci Sports Exerc 2001;33(10):1667-73. Bemben MG, Tuttle TD, Bemben DA, Knehans AW. Effects of creatine supplementation on isometric force-time curve characteristics. Med Sci Sports Exerc 2001;33(11):1876-81. Bosco C, Tihanyi J, Pucspk J, Kovacs I, Gabossy A, Colli R, Pulvirenti G, Tranquilli C, Foti C, Viru M, Vira A. Effect of oral creatinine supplementation on jumping and running performance. Int J Sports Med 1997;18(5):369-72. Fuentes RJ and Rosenberg JM. Athletic Drug Reference ’99. Durham (NC): Clean Data, Inc.; 1999. Green G. Innovations in Drug Testing. Presented at the American Medical Society for Sports Medicine Annual Meeting, Orlando (FL), April 2002. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkalloids. N Engl J Med 2000;343(25):1833-8. Jackson C. Vitamin and Mineral Use and Controversies for Strength Training. Presented at American College of Sports Medicine Annual Meeting, St. Louis (MO), May 2002. References:  References Jones AM, Atter T, Georg KP. Oral creatine supplementation improves multiple sprint performance in elite ice-hockey players. J Sports Med Phys Fitness 1999;39(3):189-96. Kreider RB, Ferreira M, Wilson M, Grindstaff P, Plisk S, Reinardy J, Cantler E, Almada AL. Effects of creatine supplementation on body composition, strength and sprint performance. Med Sci Sports Exerc 1998;30(1);73-82. Mihic S, MacDonald JR, McKenzie S, Tarnopolsky MA. Acute creatine loading increases fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men or women. Med Sci Sports Exerc 2000;32(2):291-96. Nadir A, Agrawal S, King PD, Marshall JB. Acute hepatitis associated with the use of a Chinese herbal product, ma-huang. Am J Gastroenterol 1996;91(12):1436-8. NCAA. 2001-02 NCAA Banned-Drug Classes. Available at URL: []. Poortmans JR, Auquier H, Renaut V, Durussel A, Saugy M, Brisson GR. Effect of short-term creatine supplementation on renal responses in men. Eur J Appl Physiol Occup Physiol 1997;76(6):566-67. Rico-Sanz J, Mendez Marco MT. Creatine enhances oxygen uptake and performance during alternating intensity exercise. Med Sci Sports Exerc 2000;32(2):379-85. References:  References Romer LM, Barrington JP, Jeukendrup AE. Effects of oral creatine supplementation on high intensity, intermittent exercise performance in competitive squash players. Int J Sports Med 2001;22(8):546-52. Samenuk D, Link MS, Homoud MK, Contreras R, Theohardes TC, Wang PJ, Estes NA 3rd. Adverse cardiovascular events temporally associated with mahuang, an herbal source of ephedrine. Mayo Clin Proc 2002;77(1):7-9. Schanzer W. Analysis of Non-Hormonal Nutritional Supplements for Anabolic-Androgenic Steroids – An International Study. Available through the official website of the International Olympic Committee 2002. Schilling BK, Stone MH, Utter A, Kearney JT, Johnson M, Coglianese R, Smith L, O’Bryant HS, Fry AC, Starks M, Keith R, Stone ME. Creatine supplementation and health variables: a retrospective study. Med Sci Sports Exerc 2001;33(2):183-88. Syrotuik DG, Game AB, Gillies EM, Bell GJ. Effects of creatine monohydrate supplementation during combined strength and high intensity training on performance. Can J Appl Physiol 2001;26(6):527-42. Tarnopolosky MA, Parise G, Yardley NJ, Ballantyne CS, Olatinji S, Phillips SM. Creatine-dextrose and protein-dextrose induce similar strength gains during training. Med Sci Sport Exerc 2001;33(12):2044-52. References:  References Tarnopolosky MA, MacLennan DP. Creatine monohydrate supplementation enhances high-intensity exercise performance in males and females. Int J Sport Nutr Exerc Metab 2000;10(4):452-63. Vahedi K, Domigo V, Amarenco P, Bousser MG. Ischaemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for body building. J Neurol Neurosurg Psychiatry 2000;68(1):112-3. Vandebuerie F, Vanden Eynde B, Vandenberghe K, Hespel P. Effect of creatine loading on endurance capacity and sprint power in cyclists. Int J Sports Med 1998;19(7):490-95. Volek J. Nutritional Practices for Resistance Training. Presented at American College of Sports Medicine Annual Meeting, St. Louis (MO), May 2002. Volek JS, Mazzetti SA, Farquhar WB, Barnes BR, Gomez AL, Kraemer WJ. Physiological responses to short-term exercise in the heat after creatine loading. Med Sci Sports Exerc 2001;33(7):1101-8. Volek JS, Duncan ND, Mazzettti SA, Putukian M, Gomez AL, Kraemer WJ. No effect of heavy resistance training and creatine supplementation on blood lipids. Int J Sports Nutr Exerc Metab 2000;10(2):144-56. References:  References Wallace B. Hormone “Supplements” and the Strength Athlete. Presented at American College of Sports Medicine Annual Meeting, St. Louis (MO), May 2002. Zaacks SM, Klein L, Tan CD, Rodriguez ER, Leikin JB. Hypersensitivity myocarditis associated with ephedra use. J Toxicol Clin Toxicol 1999;37(4):485-9. Peyrebrune MC, Stokes K, Hall GM, Nevill ME. Effect of creatine supplementation on training for competition in elite swimmers. Med Sci Sports Exerc 2005;37(12):2140-7. Watson G, Casa DJ, Fiala KA, Hile A, Roti MW, Healey JC, Armstrong LE, Maresh CM. Creatine use and exercise heat intolerance in dehydrated men. J Athl Train 2006;41(1):18-29. Bemben MG, Lamont HS. Creatine supplementation and exercise performance: recent findings. Sports Med 2005;35(2):107-25.

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