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Running On Empty: Fad Diets and Athletic Performance

Running On Empty: Fad Diets and Athletic Performance

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Running On Empty: Fad Diets and Athletic Performance

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  1. Running On Empty:Fad Diets and Athletic Performance National Athletic Trainers Association June 13, 2005 Gale Welter, MS, RD, CSCS University of Arizona Campus Health Service

  2. You Are the First Line of Information • Athletic Trainers (plusStrength Coaches and Personal Trainers) • Often have the closest relationship with athletes • Are trusted with personal information • Are trusted sources of information • Athletes will ask your opinion when they want to lose weight for enhanced performance

  3. When Is Weight Loss Desirable? • This could be a whole session in itself

  4. When Is Weight Loss Desirable?Things to Consider… • Optimal weight for performance? Many factors involved • Body weight vs body fat • Sensitivity to amount of body fat and disordered eating • Advisability of weight loss for performance needs careful evaluation

  5. Weight Loss Is Confusing to Athletes • Non-athlete friends’ and family members’ weight loss experiences don’t apply to athletes • Media hype everywhere; quick fix promises are very appealing • Healthy weight yardsticks for general public are not relevant to athletes (like BMI)

  6. For the Purposes of This Discussion: • Assume weight/body fat loss is appropriate and advisable • The athlete asks your advice about “diets”

  7. Objectives of This Presentation • Review energy systems • Review fuels used by energy systems • Learn the amounts of fuels provided by the “Fad Diets” and compare them to weight loss needs • Review basic performance-oriented weight loss strategies • Learn suggested talking points to use with an athlete who desires to lose weight • For effective weight/fat loss with a minimal impact on ability to train

  8. Energy Systems of Athletic Performance • Phosphagen system(a.k.a. creatine phosphate system) – very limited ATP* supply • Anaerobic system – Some ATP* • Aerobic system – Lots of ATP* *basic energy currency in cells.

  9. Phosphagen System • Short burst, all-out effort • 5-6 seconds duration • Quick, but limited energy source • Creatine-phosphate stored in muscles • small amounts • Oxygen not necessary • By-products of ATP breakdown in this system initiates the anaerobic glycolysis system

  10. Anaerobic System • Bursts of activity lasting 60-180 seconds • Relatively quick energy transfer • Lactic acid build-up decreases pH of cell, limiting continuation • Fuel is Carbohydrate (glucose) • Oxygen is not needed

  11. Aerobic System • Moderate or low intensity activity over extended periods of time • Slower energy transfer • Greatest capacity because of fuel availability • Carbohydrate, limited storage (~ 1900 calories) • Fat, unlimited storage capacity • Protein only as a reserve fuel, conversion to glucose takes energy to do • Oxygen required

  12. AMINO ACIDS FATTY ACIDS GLUCOSE Cell Membrane Inside Cell Anaerobic (without oxygen) SomeATP Aerobic (with oxygen) Lots of ATP University of Arizona, Winning Sports Nutrition, 2004

  13. Low Intensity Activity High Intensity Activity Glucose Fatty Acids Amino Acids University of Arizona, Winning Sports Nutrition, 2004

  14. Diet and Training • Can influence the capacity of the energy transfer system • Can optimize the storage and utilization of carbohydrate and fat

  15. Primary Fuel Source - Carbohydrate • Direct fuel, as glucose • Glucose is also necessary • Forfat oxidation to produce energy • To fuelprotein’s functions of repair, maintenance, and growth • To convert protein to glucose for energy, when needed • Stored form of glucose is called glycogen

  16. Carbs Currently Have a Bad Rep

  17. Athletes are Bombarded byLow-Carb Messages

  18. Tough Sell #1 • Convincing athletes that these messages do not apply to them, because their primary fuel source for performance energy is carbohydrate foods.

  19. Athletes Need a Regular Supply of Carbohydrate • Starches • Grains • Fruits • Vegetables

  20. Inadequate Carbohydrate Intake

  21. Inadequate Carbohydrate Intake

  22. Athletes Need More Protein Than the General Public, to meet their higher needs for: • All structural tissue growth and tissue repair • Oxygen-carrying hemoglobin • Enzymes, hormones, immune function, etc. General PublicAthlete 0.8g / kg body wt 1.2 – 2.0g / kg body wt (0.4g / lb. body wt)(.5 - .9g / lb. body wt) Rosenbloom, CA. Sports Nutrition, A Guide for the Professional Working with Active People. 3rd Ed., American Dietetic Association, 2000

  23. Tough Sell #2 Athletes Do Not Need an Extraordinary Amount of Protein • 130 lb female athlete needs 65 – 117 g/d (Non-athlete needs = 52 g/d) • 200 lb male athlete needs 100 – 180 g/d (Non-athlete needs = 80 g/d)

  24. What does 100g Protein look like ? Source: exchange system estimates

  25. What does 180g Protein look like ? Source: exchange system estimates

  26. Dietary Fat Is Essential: • As a structural component of all cells • For brain and nervous system growth and maintenance • For sex hormone production • For immune response • To keep skin and other soft tissue pliable • For blood clotting, blood pressure regulation, heart rate

  27. Fat Deficiency Is Marked By: • Low sperm counts • Loss of menstral function • Increased susceptibility to infections • Food cravings • Irritability • Anxiousness • Mild depression

  28. Tough Sell #3Quality Fats/Oils Contribute to Optimal Performance • Especially to female athletes, smaller athletes and some coaches who believe that dietary fat = body fat • It is difficult for many to understand that additionalbody fat is a result of eating more calories from the total of all food ( and beverage) sources than are being used up… and doing so consistently over time

  29. Different Sports, Different PositionsSlightly Different Needs • Power/Strength sports • Weight lifting, wrestling, gymnastics, ice skating, track/swim/bike sprints, throwing, diving, football • Intermittent (stop and go) sports • Team sports: baseball, softball, basketball, volleyball, soccer, lacrosse, hockey, football etc. • Individual sports: tennis, golf, etc • Endurance sports • All long distance run/swim/bike, or combination; some positions in soccer, lacrosse, etc.

  30. Current Best ScienceEnergy Needs of Athletes Rosenbloom, CA. Sports Nutrition, A Guide for the Professional Working with Active People. 3rd Ed., American Dietetic Association, 2000

  31. Many Factors Effect Weight/Fat Loss • Timing of meals and snacks • Sleep • Stress levels • Psychology: drive to win • Personal / Emotional • Relationships • Finances • Expectations of others, need for acceptance

  32. Every Athlete Is Different • Different genetics • Body type, enzyme and hormone makeup • Athletic potential • Different body size • Different food preferences and cooking skills • Different emotional relationships with food • Different ages and stages in sport • Different athletic ambitions • Different emphasis on social life • Different money available

  33. Different Sports, Different PositionsSlightly Different Needs • Power/Strength sports • Weight lifting, wrestling, gymnastics, ice skating, track/swim/bike sprints, throwing, diving, football • Intermittent (stop and go) sports • Team sports: baseball, softball, basketball, volleyball, soccer, lacrosse, hockey, football etc. • Individual sports: tennis, golf, etc • Endurance sports • All long distance run/swim/bike, or combination; some positions in soccer, lacrosse, etc.

  34. Power / Strength Endurance For Comparison to Fad Diets Use Nutrition Needs of an Endurance and a Power Athlete

  35. Weight Maintenance - Female Using low end of estimated needs with some rounding.

  36. Weight Maintenance - Male Using low end of estimated needs with some rounding.

  37. Endurance Female – “Fine Tuning” Weight/Fat Loss Advisable

  38. Power Male – “Basic Performance”Weight/Fat Loss Advisable

  39. The Appeal of Fad Diets • Promise quick weight loss • Provide a “plan” • Have a certain sociability to them

  40. Categories of Fad Diets 1. High Protein, High Fat, Low Carb 2. Lower Carb, Higher Protein, Moderate Fat 3. Low Fat and Very Low Fat 4. Moderate Fat, Nutrient Balanced

  41. High Protein, High-Fat, Low Carb Fad Diets • Atkins • Protein Power • Carbohydrate Addict’s Diet

  42. Endurance Female5’3” 135 lb ≤ 10 lb Wt/Fat Loss Goal Footnotes a, b and c – see separate slides following

  43. Power Male6’3” 280lb ≥ 30 lb Wt/Fat Loss Goal Footnotes a, b and c – see separate slides following

  44. PRO Can adjust quantity by nutrient (fat or protein) to meet greater calorie needs CON Carbs provided are too low to fuel athletic performance, even in off season Fatigue, irritability, constipation reported Atkin’s and Carb Addict’s have unisex diet levels where no calculations are based on current wt or activity level High Protein, High-Fat, Low Carb Fad Diets

  45. Lower Carb, Higher Protein, Moderate Fat Fad Diets • The Zone • South Beach • Sugar Busters

  46. Endurance Female5’3” 135 lb ≤ 10 lb Wt/Fat Loss Goal Footnotes a, d, e, and f – see separate slides following

  47. Power Male6’3” 280lb ≥ 30 lb Wt/Fat Loss Goal Footnotes a, d, e, and f – see separate slides following

  48. PRO Zone could meet needs of power athlete S. Beach close to meeting calorie needs of endurance athlete, if adj’d to swap calories from fat to carbs CON Zone compliance low due to Learning about and eating in“blocks” of carb/protein/fat takes effort Repetitious S. Beach and Sugar Busters don’t use calculations based on nutrient needs and wt, rather, they rely on athlete to make adjs without specific directions have too few carbs fat too high for endurance/smaller athlete protein too low for power athlete Lower Carb, Higher Protein, Moderate Fat Fad Diets

  49. Low-Fat and Very-Low-Fat Fad Diets • Ornish Diet

  50. Endurance Female5’3” 135 lb ≤ 10 lb Wt/Fat Loss Goal Footnote a – see separate slide following