Welcome to FCSN/PE 446 Sports Nutrition and Weight ControlCan Nutrition Make a Difference?Energy Systems for ExerciseHuman Energy SystemsSlide 5ATP-PC SystemSlide 7Slide 8Creatine as an Ergogenic AidSlide 10Slide 11Is Creatine an Erogenic Aid?Levels of evidence for ergogenic effectsSlide 14Slide 15Slide 16Slide 17Creatine supplementation enhances muscular performance during high-intensity resistant exercise. JADA 97:765-770 (1997)Slide 19Slide 20Slide 21Creatine supplementation does not improve sprint performance in competitive swimmers. MSSE 28:1435-1441(1996)Slide 23Slide 24Nutrition Science Club General MeetingACSN Consensus Statement Creatine SupplementationSlide 27Creatine as an Ergogenic Aid MiscellaneousSlide 29Dietary Supplements as Ergogenic Aids: Let the Buyer Beware!Dietary Supplements: The NFL Player’s Association Recommendation http://www.nflpa.org/members/main.asp?subPage=Steroid+PolicyNCAA: Permissible Nutritional Supplements NCAA Bylaw 16.5.2.2 (2000) (web page link)Lactic Acid SystemSlide 34Slide 35Slide 36Lactic Acid SystemSlide 38Slide 39Oxygen Energy SystemsSlide 41Slide 42Slide 43Slide 44Slide 45Slide 46% Contribution of Aerobic and Anaerobic Energy SourcesSlide 48Human Energy Stores Sources of energy for energy systemsSlide 50Human Energy StoresSlide 52Slide 53Slide 54Upcoming schedule Spring 2006Exercise Energy Metabolism: Examples of experimental/real dataExample 1: Metabolic Fuels During Intense Exhaustive ExerciseSlide 58Slide 59Key Points In repeated one minute sprints:Example 2: Glycogen Utilization During Endurance ExerciseSlide 62Key PointsExample 3: Glycogen Degradation Rate During ExerciseSlide 65Slide 66Example 4: Effect of Glycogen Level on Rating of Perceived ExertionSlide 68Slide 69Example 5: Effect of Initial Muscle Glycogen Levels and EnduranceSlide 71Key Points Initial Glycogen Levels and EnduranceOk, all this treadmill running is interesting (kind of…), but what about performance in sport games??Example 6a: Muscle Glycogen and Soccer Performance (Agnevik, 1970)Example 6b: Muscle Glycogen and Soccer Performance Saltin, 1973Key Points Diet and Soccer PerformanceExample 7: Effect of Successive Days of Intense Training on Glycogen Content Costill & Miller (1980)Slide 78Key Points: Effect of Successive Days of Intense Training on Glycogen ContentQuiz - Monday, April 17Metabolic Causes of Fatigue During Exercise. Table 3.9 (Williams)Slide 82Metabolic Causes of Fatigue During Exercise.Slide 84Slide 85Slide 86Slide 87Welcome to FCSN/PE 446Sports Nutrition and Weight ControlDavid L. Gee, PhDwww.cwu.edu/~geedCan Nutrition Make a Difference?If a change in diet or use of a dietary supplement could improve performance by 1%, does it really matter?2005 Tour de France1st Place – Lance Armstrong•Total time = 86 hours and 15 minutes10th Place – Oscar Pereiro Sio (Spain)•Total time = 86 hours and 31 minutes–Lance was faster by 0.3%If Lance was slower by 1%, he would have finished in 27th place.Energy Systems for ExerciseFCSN/PE 446Dr. David L. GeeProfessor of Food Science and NutritionHuman Energy Systems ATP-PC System•adenosine triphosphate•phosphocreatine Lactic Acid System•anaerobic glycolytic pathwayOxygen System•aerobic metabolic pathwaysATP-PC Energy SystemATP – Energy for muscle contractionATP-PC SystemATPhighest rate of energy productionlowest total energy capacityall energy for muscle contraction must flow through ATPATP-PC SystemPhosphocreatineRapid equilibrium with ATP/ADPHighest rate of energy productionLowest total energy productionCreatine as an Ergogenic AidClaims for creatine (monohydrate)•EAS web page (2002)“...may boost muscle size and strength, increase lean body mass, delay fatigue, and speed muscle recovery after exercise.”Creatine as an Ergogenic AidCreatine Loading Protocol25-30 grams/day for 3-5 days3-5 grams/day for maintenanceor 3-5 grams/day for gradual loadingtypical dietary creatine = 1g/dcost (EAS Phosphagen, 3/02)•$16 for loading•$36 per month for maintenance ($432/yr)Is Creatine an Erogenic Aid?Levels of evidence for ergogenic effects1. Is there a sound hypothetical mechanism explaining potential ergogenic effects?Levels of evidence for ergogenic effects2. Are there biochemical indicators that suggest ergogenic effects?3. Are there studies that demonstrate improvement of physical performance?Creatine as an Ergogenic AidTheoretical Basiscreatine phosphate levels limit ATP production during maximal exerciseTherefore, supplementation will increase cellular CP levels and increase high intensity performanceCreatine as an Ergogenic AidBiochemical evidencesupplementation of creatine does result in increased muscle creatine concentration•16% increase in muscle creatine after 6 day @ 20g/d–Hultman et al, JAP 81:232-237 (1996)Creatine as an Ergogenic AidScientific Performance EvidenceIdeal investigation:•Randomized double blind placebo trialtypically increases muscle Crtypically results in increased LBM •0.7-1.6kg•water or protein ?•may impair performanceCreatine supplementation enhances muscular performance during high-intensity resistant exercise.JADA 97:765-770 (1997)14 active men•randomized, double blind w/ placebo•25g Cr/day for 6 days•Tested on three occasions–Before supplementation–After 6 days of placebo capsule supplementation–After 6 days of either placebo or creatine capsule supplementation•bench press (5 sets of 10 reps to failure)•squat exercise (5 sets of 10 reps to failure)Creatine supplementation enhances muscular performance during high-intensity resistant exercise.JADA 97:765-770 (1997)Conclusion:•One week of creatine supplementation (25g/d) enhances muscular performance during repeated sets of bench press and jump squat exercise.Creatine supplementation does not improve sprint performance in competitive swimmers.MSSE 28:1435-1441(1996)28 trained competitive swimmers•randomized, double-blind placebo trials•5 days 20g creatine/day or placebo•25, 50, 100 meter trials, best strokeResults•no significant differences in performance times between trials or groups•no effect of Cr on post-exercise blood lactateCreatine as an Ergogenic AidMany, but not all studies show increases in power outputgenerally seen in high power, repetitive exercise testsCreatine as an Ergogenic AidNo (?) long term safety tests•No consistent