Sports Nutrition

Nutrition and Nutritional Supplements in SportsObjectivesIncrease awareness that nutrition can affect an athletes performanceDiscuss current nutritional recommendations for athletesReview the 1994 Dietary Supplement Health and Education ActDefinition of a supplementImpact of this legislationDiscuss specific nutritional supplements commonly used by athletesDo they work?Are they safe?Review the Anabolic Steroid Control Act of 2004Performance Influencing Factors Genetics

Training and Conditioning

NutritionDeterminants of the Athletes Energy RequirementsDuring intense exerciseCarbohydrate stored in muscles and liver (glycogen) is predominant fuel sourceDuring prolonged exerciseFat stores are predominant fuel sourceFitness level of the athleteWell trained endurance athletes burn fat more efficiently, sparing limited glycogen storesFormula for Estimating the Bodys Calorie RequirementsSedentary personWeight (kg) x 25Moderately active personWeight (kg) x 30Active person (endurance athlete)Weight (kg) x 40Underweight personWeight (kg) x 45kg = lbs / 2.2Recommendations for AthletesCarbohydrate intakePre-exercise mealCarbohydrate loadingProtein intakeFat intakeCarbohydratesNon-essential nutrient (human body can make sugar)Simple (sugars) and Complex (starches), FiberMajor fuel source for exercising muscle4 Kcal/gramBread, pasta, beans, potatoes, bran, rice, cerealsAthletes should ingest 6 to10 gm/kg/day60 to 70% of total calories should come from carbohydratesComplex carbohydrates (starches) are preferableDuring exerciseAthletes should consume 25 to 30 gm of carbohydrate for every 30 minutes of exerciseAthletes should drink 6 to 8 ounces of water or sports drink for every 10 to 15 minutes of exerciseCarbohydratesAfter exerciseAthletes should consume 1.0 to 1.5 gm/kg immediately post exercise and again one hour laterTo replace muscle glycogen storesTo prevent gradual depletion of muscle glycogen stores over time caused by repetitive daily bouts of heavy exerciseTo decrease muscle breakdownWhy Complex Carbohydrates?Compared to ingesting simple carbohydrates, ingesting complex carbohydrates:Increases muscle glycogen stores betterImproves performance and delays fatiguePromotes faster stomach emptyingCauses less stomach upset and indigestionLeads to lower blood sugar and insulin levels Provides other beneficial nutrientsFiber, vitamins and mineralsPre-exercise MealImportanceLess hunger before and during exerciseMaintains optimum glycogen storesRecommendationsEmphasize complex carbohydrates (starches)1 to 4 gm/kg about 1 to 4 hours prior to eventConsume less closer to eventAvoid high fat and high protein foodsSlower gastric emptying can cause stomach upsetAvoid high fiber or gas forming foodsCan lead to crampy abdominal painCarbohydrate LoadingIncreases the bodys pre-exercise glycogen stores by 50 to 100%Benefits endurance athletes who compete for longer than 90 minutesCan increase endurance up to 20%Can increase performance by 2 to 3%Carbohydrate Loading:One Example of HowDays prior to eventExercise durationCarbohydrate 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/dayProteinAthletes require more protein than non-athletesProtein promotes growth and repair4 Kcal/gramChicken, fish, egg whites, red meat, nuts12 to 18% of total calories should come from protein1.2 to 1.4 gm/kg/day recommended for endurance athletes1.7 to 1.8 gm/kg/day recommended for strength athletesAverage American diet provides 1.4 gm/kg/dayAdequate calorie intake is just as important as adequate protein intake for building musclesToo much protein intake can be badExcess protein calories are stored as fatExcess protein intake can lead to dehydration and may contribute to kidney problemsFatMajor source of energy, serve as energy stores9 Kcal/gram25 to 30% of total calories should come from fatLess than 10% of total calories should come from saturated fatsSaturated, monounsaturated, polyunsaturated, transCholesterol intake should be less than 300 mg/dayAverage American diet provides 37% of total calories from fatGood choices: Olive oil, nuts, avocados, fish oilBad choices: Vegetable oil, margarine, beef fat, pork fatNutritional Supplements1994 Dietary Supplement Health and Education ActDefinition of a supplementAny product that contains vitamins, minerals, amino acids, herbs, botanicals or a concentrate, metabolite, constituent, extract or combination of any of these ingredientsRemoved dietary supplements from FDA regulation on the front endFDA must prove a supplement is dangerous before its sale can be prohibitedNutritional Supplements1994 Dietary Supplement Health and Education ActManufacturers do not have to provide scientific proof of claimsManufacturers cannot state product is meant to diagnose, treat, prevent or cure a disease but can make indirect suggestionsCreated a multi-billion dollar industry that continues to grow rapidlyVitamins and MineralsEssential nutrientsHuman body needs these to produce energyNo evidence in U.S. studies that taking vitamin and mineral supplements improves athletic performanceBeing deficient in vitamins or minerals is rare in the U.S. compared to the rest of the worldA few studies outside U.S. showed an effectDid 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 calciumAthletes who are strict vegetarians should take a multivitamin to prevent deficiencies and a calcium supplement (1000 mg/day) to help prevent bone lossVitamins and MineralsSpecific vitamins and minerals studiedVitamin A and Vitamin DNo evidence of increased performanceMay have toxic effects at high dosesVitamin ENo evidence of increased performanceToxic effects are rareVitamin CAnti-oxidant effect may help decrease exercise related muscle sorenessNo effect on strengthPossible toxic effects at high dosesVitamins and MineralsSpecific vitamins and minerals studiedVitamin B6No evidence of increased performanceToxic 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 damageStudy results are conflictingShould not exceed 100% U.S. RDA of anti-oxidantsBuyer beware!Some supplements have been found to contain up to 3000% of U.S. RDA for vitamins and mineralsCreatineChemical name: Creatine-MonohydrateNaturally available in meat and fishNCAA study found creatine supplements used by 12% of college athletesA subsequent survey of high school athletes showed similar usage ratesDoes it work toIncrease muscle mass?Increase strength?Increase performance?Is it safe? CreatineStudies showing (+) effects in healthy subjects published Increased high intensity, intermittent exercise performance in squash playersIncreased cell hydration status and performance variables in Division I college football players more than training aloneAugments repeated sprint cycle performance in hot environment without altering thermoregulatory responsesIncreases indices of high intensity exercise performance for both males and femalesIncreased capacity of human muscle to perform work during alternating intensity contractionCreatineRecent studies with (+) effects (continued)Ergogenic effect in elite ice hockey playersLoading improves intermittent sprint capacity at end of endurance exercise to fatigueAdding 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 trainingHelped to prolong time maximal rate of power output could be maintainedCreatineStudies with no effect in healthy subjectsDid not positively influence isometric strength in untrained (sedentary) malesDid not increase performance or training volume over placebo in rowers that performed a high intensity rowing and strength programNo statistically significant difference in strength or fat free mass gains after a resistance exercise training program compared with post exercise protein supplementation

CreatineStudies looking at safety of supplementation in healthy subjectsRetrospective study of 26 athletes who reported taking creatine between 0.8 and 4 years - blood chemistries including liver and kidney function were all within normalNeither 12 weeks of supplementation with training nor training alone had any effect on serum cholesterol, HDL, LDL, TG or creatinine levelsSupplementation for 5 days had no effect on BP, serum creatinine, estimated creatinine clearance or plasma CKOral supplementation for 5 days had no effect on GFR, total protein or albumin excretion rates and all remained normalCreatineOpinionSupplementation in combination with high intensity strength training increases strength during high intensity intermittent exercise 7 to 8% more than training aloneSupplementation probably increases performance in sports involving or requiring high intensity intermittent bursts of strengthLong term effects (chronic use > 4 years) are not known and I share concern of some experts about potential for liver and kidney problemsDosingLoading: 20 to 30 gm/day for one weekMaintenance: 10 to 15 gm/day while trainingHMBChemical name: Hydroxy-MethylbutyrateMetabolite of leucine (amino acid)Available naturally in catfish, citrus fruits and breastmilkSome preliminary studies suggest that supplementation with HMB can suppress muscle protein breakdownOne placebo-controlled study in weightlifters reported slightly better strength increases and greater lean mass increases in the group taking HMBNo known adverse effectsDosing: 1 gm three times a dayEphedra or MaHuangHerbal forms of the stimulant ephedrine80+ confirmed deaths related to ephedra useExperts suspect many more unconfirmed deathsAdverse effectsHigh blood pressure (most common)Palpitations and increased heart rateSeizureThermoregulatory dysfunctionStrokeHeart attackSudden deathVasculitisAllergic myocarditis (one case reported)Acute hepatitis (one case report)Ephedra or MaHuangFollowing the death of two professional athletes, FDA banned sale of Ephedra as a nutritional supplementSince this time, manufacturers have started substituting other stimulantsCitrus AurantiumOrange extractChemical structure very similar to ephedrineOther Nutritional SupplementsChromium PicolinateNo benefit demonstrated in studiesAdverse effects: stomach upset, anemia, cognitive impairment, chromosome damage, interstitial nephritisL-CarnitineNo benefit demonstrated in studiesAdverse effect: significant muscle weaknessL-TryptophanNo benefit demonstrated in studiesAdverse effect: eosinophilia myalgia syndromeAnabolic Steroid PrecursorsDehydroepiandrosterone (DHEA) and Androstenedione (Andro)Chemicals that can be converted into testosterone in human biochemical pathwaysNaturally available in wild yamsAn early study done by a manufacturer of these products showed no significant increase in blood levels of testosteroneStudy 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 PrecursorsSubsequent independent scientific studiesDHEADoes not seem to have much if any effect on fat-free body mass and strengthAndrostenedioneCauses a temporary increase in testosterone levelsHas no effect on bodys ability to make proteinDoes not seem to have any effect on strengthNo long term effect on blood testosterone levelsChronic use causes increase in estrogen levelsAnabolic Steroid PrecursorsPotential adverse effectsMay cause liver damageIn femalesCan cause male features in womenMay increase risk of uterus cancerIn malesCan cause female features in menMay increase risk of prostate cancerAnabolic Steroids and Anabolic Steroid PrecursorsAre banned and tested for by the USOC, IOC, NCAA, NFL, NBA and MLB (finally!)NHL has no official policy and does not perform testingYou can be disqualified from participating in college sports if you test positive for a substance banned by the NCAAWhether or not you knew it was bannedWhether or not the product was mislabeledBuyer Beware!IOC funded study by Shanzer (Germany) from 10/00 to 11/01Analyzed 634 products labeled as non-hormonal nutritional supplements from 13 countries and 215 different suppliers94 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 micrograms per gram of supplement23 products contained steroid precursors of nandrolone and testosterone64 products contained steroid precursors of testosterone only7 products contained steroid precursors of nandrolone onlyPercentage of positive supplements per country25.8% of products bought in Netherlands22.7% of products bought in Austria18.8% of products bought in UK18.8% of products bought in US (45 positive out of 240 tested)Anabolic Steroid Control Act of 2004Signed into federal law on October 22, 2004Amends the Anabolic Steroid Control Act of 1990Modifies the definition of anabolic steroids to include tetrahydrogestrinone (THG), androstenedione, and specified related chemicalsDirects the U.S. Sentencing Commission (USSC) to review federal sentencing guidelines with respect to anabolic steroid-related offensesAmends guidelines to provide for increased penaltiesAuthorizes the Attorney General to exempt from regulation any compound, mixture, or preparation containing an anabolic steroid that does not present a significant abuse potentialDirects 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 NSDUH includes questions concerning the use of these drugs.Source: Library of CongressConclusionsNutrition plays an important role in an endurance athletes ability to performProper nutrition in combination with sound and proven training techniques can help endurance athletes to maximize their genetic abilitiesCreatineHas been shown to increase strength during intermittent high intensity exerciseHas not been shown to improve performance in endurance athletesSafety of long-term use is not knownCertain nutritional supplements have not demonstrated any performance benefit in studiesConclusionsCertain nutritional supplements can have potentially dangerous side effectsFurther legislation is needed to address the dangers of some nutritional supplementsProfessionals in the community need to be resources of good information for athletes, parents and coaches PhysiciansPhysician assistantsNurse practitionersAthletic trainersSchool nursesDieticiansReferencesBemben 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.ReferencesJones 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: [http://ncaa.org/sports_sciences/drugtesting/banned_list.html].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.ReferencesRomer 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, OBryant 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.ReferencesTarnopolosky 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.ReferencesWallace 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.http://www.usdoj.gov/ndic/pubs11/12620/steroids.htm