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Protein and Exercise for the Athlete

Presented By: Jessica Calhoun Heather Mason Thusita Kannangara October 11, 2010. Protein and Exercise for the Athlete. Image fromtalk.gagajoyjoy.com. Introduction. Americans have become obsessed with protein!

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Protein and Exercise for the Athlete

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  1. Presented By: Jessica Calhoun Heather Mason ThusitaKannangara October 11, 2010 Protein and Exercise for the Athlete Image fromtalk.gagajoyjoy.com

  2. Introduction • Americans have become obsessed with protein! • In gyms, restaurants, medical offices and stores we are bombarded with ads and displays of protein supplements. • Many of these beliefs about protein are incredibly exaggerated or just plain wrong.

  3. Protein • Derived from Greek “of first rank” or “primary” • Found in 40% of skeletal muscle, 25% in organs and the remainder in the skin and blood • Play vital roles in almost every biological process • Macromolecules composed of C, H, O and N which are formed when large amounts of subunits or amino acids link together creating long chains

  4. Protein Structure • Composed of amino acids (AA’s) • Contain a central carbon atom, amino group (NH2), carboxylic group (-COOH), and a side chain. • Twenty AA’s, 9 essential • Complete proteins contain all 9 essential AA’s Image brainandbeauty.com

  5. It is Easy to Get Enough Protein ALL Animal sources Vegetable Sources Soy Tempeh Grains Nuts Beans Soy/ Almond milk Starchy vegetables • Meat • Poultry • Fish • Milk • Cheese • Yogurt

  6. Protein Requirements • Requirements reflect the need to offset protein losses to maintain nitrogen homeostasis • Proteins constantly being synthesized and degraded “protein turnover” • Most AA’s are recycled, but a small portion are oxidized and must be replaced

  7. Overview of Protein Turnover

  8. Digestion and Absorption • Protease enzymes in the stomach and small intestine (SI), break down the amino acid chains in proteins into polypeptides • then further separate into individual amino acids. • Absorption occurs along the SI • Absorption of AA’s into the intestinal cells requires carriers; but paracellular absorption can also occur • In general, BCAA absorbed faster than smaller amino acids

  9. Dietary Recommendations • DRI for healthy individuals: 0.8 g/kg/day • Strength and endurance athletes may have increased needs • Endurance athletes: 1.2 to1.4g/kg/day • 9-10% daily energy • Resistance athletes: 1.6 to 1.7g/kg/day • 14-15% daily energy • Extra protein is needed to repair damaged muscle fibers, decrease the rate of muscle protein breakdown, replenishment of depleted energy stores, and synthesis of new protein molecules

  10. History of Protein & Exercise • 18th century: muscles primarily composed of protein • 18th century: Belief that protein was the major fuel source during exercise • Observations of affluent laborers diets lead to the “Voit Standard” or 118 grams of pro/day • 1904: 35–50 g of protein a day was believed adequate for adults • 2010: It is understood that the major energy fuel source is carbohydrates and not protein

  11. Protein Excess • Coronary artery disease • Dehydration • Increased Calcium excretion • Supplements – possible risk for toxicity and metabolic imbalances • Strain on liver and kidneys

  12. Protein Deficiency • Edema • Anemia • Muscle atrophy • Hormone imbalance • Severe cases: Marasamus & Kwashikor http://www.bio.ilstu.edu/armstrong/syllabi/cassava/cassava8.htm

  13. Branched-Chain Amino Acid Supplementation and Indicators of Muscle Damage After Endurance Exercise Greer, B. , Woodard, J. , White, J. , Arguello, E. , & Haymes, E. (2007). Branched-chain amino acid supplementation and indicators of muscle damage after endurance exercise. International Journal of Sport Nutrition & Exercise Metabolism, 17(6), 595-607. Image- the-fitness-motivator.com

  14. Purpose • Determine if branched-chain amino acid (BCAA) supplementation decreases indicators of muscle damage compared with a carbohydrate (CHO) beverage or a noncaloric placebo (PLAC) beverage. Image Justsupplements.com

  15. Background • Goal is to reduce muscle damage during training • BCAA may reduce the extent of muscle damage via the release of anabolic hormones or by inhibiting proteolysis • Ingesting BCAA’s pre and post workout has been shown to decrease post exercise creatine kinase (CK) and lactate dehydrogenase (LDH) activities

  16. Methods • Nine untrained, healthy college men • Kept detailed diet record and were encouraged to maintain the same dietary pattern • Avoid eating for 3 hours before each trial • Subjects assigned to 1 of 3 treatment orders • Exercise at 50% V02 max for 90 min. • Beverages were administered at 5 minute pre exercise and at 60 min. mark.

  17. Methods • Subjects blinded to beverage, same taste and appearance • BCAA beverage – isoleucine, leucine, valine (200 kcal) • Isocaloric CHO beverage (Gatorade) (200 kcal) • PLAC- noncaloric, water, artificial sweetener, lemon flavor, and salts

  18. Branched-Chain Amino Acids Image agron.iastate.edu

  19. Dependent Variables • Creatine kinase (CK) • Lactate dehydrogenase (LDH) • Isokinetic leg extension torque • Led flexion torque • Muscle soreness of quads (self rating) • Measurements taken before exercise and at 4, 24, and 48 hours post exercise

  20. Results • CK activities significantly lower after the BCAA trial than in the PLAC trial at all times, only lower than the CHO at 24 h • CK lower in the CHO trial than PLAC at 24 and 48 h • LDH was lower in the BCAA trial at 4 H, no sig. difference between CHO and BCAA • No sig. effects for leg extension torque • Leg flexion torque in the BCAA trial was significantly greater than both the CHO and PLAC trials at 48 h postexercise

  21. Leg Extension torque increased, but not significantly  Leg Flexion Increased significantly at 48 h 

  22. Perceived Muscle Soreness

  23. Conclusion • Data suggests BCAA supplementation attenuates muscle damage during prolonged endurance exercise in untrained college age men • Smaller changes in markers in this study than previous, isocaloric? • Intensity too low? • AA with coingestion of CHO may be more effective than AA alone • Possible mechanism- when ingested before aerobic exercise BCAA increases concentrations of human growth hormone and helps attenuate a drop in testosterone, resulting in more anabolic environment

  24. Evaluation Strengths • Subjects blinded • Isocaloric beverage • Average athlete, not highly trained • All subjects performed all three trials • Separated by 8 weeks Limitations • Researchers not blinded • No women • Small sample size • Intensity too low? • Only theorized mechanism

  25. Timing Protein Intake Increases Energy Expenditure 24 h after Resistance Training Hackney, K., Bruenger, A., Lemmer, J. (2010). Timing Protein Intake Increases Energy Expenditure 24 h after Resistance Training. Medicine and Science in Sports and Exercise. 42(5), 998-1003. http://tiptoptone.com/resistance_training.html

  26. Purpose To determine the effect of protein (PRO) supplementation before an acute bout of heavy resistance training (HRT) on post exercise resting energy expenditure (REE) and the non protein respiratory exchange ration (RER). Hypothesis: REE would be increased and RER would be decreased up to 48 hours after HRT in those receiving PRO compared with CHO

  27. Methods • Double-blind two trial crossover design • 6 resistance trained men, 3 trained women • Measure one rep max (RM) • 4 day dietary journal • Consumed supplement 20 mins before single bout of HRT • PRO supplement- 18 g whey, 2 g CHO, 1.5 g fat • CHO supplement- 19 g CHO, 1 g PRO, 1 g fat • REE measured 4 consecutive days with Sensor Medics metabolic system

  28. Results • REE elevated significantly in both CHO and PRO groups at 24 and 48 h post HRT • REE in response to PRO was significantly greater compared with CHO at 24 h • RER decreased significantly in both groups at 24 h compared to baseline • No differences observed in total energy intake or HRT volume = sets x reps x kg lifted

  29. Conclusions • Reduced RER indicates there is greater reliance at fat oxidation at rest • Ingesting protein before HRT may be an effective way to increase energy expenditure • Increases in REE may lead to improvements in body composition • Volume was not increased so did not increase strength!

  30. Evaluation Strengths • Men and women • Double-blind • Controlled diet • 40 references, many within the last 10 years Limitations • No control group • Small sample size • Could use more graphs for clearer data presentation

  31. Protein Considerations for the Vegetarian Athlete

  32. Vegetarian Diets Can Easily Meet Protein Needs • Health, ethical, religious reasons • Range of vegetarianism from semi veg. to vegan • Observational studies have not detected differences in performance • Short term intervention studies have had similar results

  33. Decreased Digestibility of Plant Sources • Protein about 85% digestible from plant diet compared to 95% with mixed diet • RDA .9 g protein/ kg BW/ day for regular human • Most people surpass this amount • RDA could be increased to 1.3 to 1.8 g/ kg for athlete • No need for strict combination of foods • Choose a variety of plant sources from all food groups and achieve adequate protein balance

  34. Vegetarian Sources of PRO Vegan • Soy Milk • Tofu • Tempeh • Certain Veggie burgers • Nuts • Peanutbutter • Beans • Corn, potatoes • Whole grains Vegetarian • Vegan foods plus • Milk • Eggs • Cheese • Fish? Image al.godsdirectcontact.org

  35. Effect of dietary protein content during recovery from high-intensity cycling on subsequent performance and markers of stress, inflammation, and muscle damage in well-trained men Rowlands, D. S., Rossler, K., Thorp, R. M., Graham, D.F., Timmons, B. W., Stannard, S.R., Tarnopolsky, M. A. (2008). Effect of dietary protein content during recovery from high-intensity cycling on subsequent performance and markers of stress, inflammation, and muscle damage in well-trained men. Applied physiology, nutrition, and metabolism, 33(1), 39-51. http://www.treehugger.com/files/2008/09/helmet-debate-is-over.php

  36. Background • It may be most beneficial to consume protein during immediate hours of post exercise. • Exercised muscle has increased blood flow, amino acid uptake and protein synthesis • Amino acid uptake from high protein meal appears to be greatest following exercise

  37. Objective • Evaluate the effect of post exercise protein consumption on next day high intensity cycling performance • Investigate presence of recovery and evaluate high intensity performance after 3 days.

  38. Methods • Double-blind, randomized, crossover design • 12 trained male cyclists • Cyclists performed 3, 2.5 hour programmed cycling endurance exercise tests over a 4 day period in the laboratory. Day 3 was a rest day. • Day 1 & 2, each cyclist consumed treatment. • The protein group received 0.8 g of pro/kg/hr in form of bar or beverage. Control group consumed 0.12 g pro/kg/hr and 2.35g cho/kg/hr • Instructed to consume 8 times throughout a 4 hour period.

  39. Methods • Day 1 – Cycling protocol performed. Treatment was given and blood samples taken every 30 min over 3 hour period. • Day 2 – Blood samples -> cycling protocol -> treatment -> blood samples 3x in 90 minutes. • Day 3 – Rest day. Rich CHO diet provided to replenish glycogen stores • Day 4 – Repeat performance of day 2

  40. Measurements • Sensation perception charts for sprints and intervals on days 2 and 4 • Plasma lactate, glucose, creatine kinase (CK) cortisol, interleukin-6, C Reactive Protein (CRP), tumor necrosis factor, • Net nitrogen balance

  41. Results • Overall mean sprint power in protein group was greater on day 4 and less in control group • Minor increases in strength and less nausea reported in protein group on day 4 • Relative to control, protein group had reduced CK before exercise on day 4 • Day 1 post exercise to day 2, control had positive N balance and negative in control. • Relative to control, plasma lactate was higher in control during sprints • No significant differences in glucose, cortisol& Interleukin 6

  42. Conclusion • High protein post exercise diet followed by a high carbohydrate diet may enhance endurance sprinting performance in subsequent performance days. http://gymaddicts.com/the-benefits-of-protein-bars/

  43. Evaluation Strengths Limitations Small sample size (n=12) Low external validity 30 y/o male cyclists Cyclists complained of being full Unrealistic to consume frequent and large amounts of pro bars/beverages post exercise Invasive Possible Day 2 and Day 3 non dietary compliance Limited similar studies Minimal studies with endurance athletes and protein recovery • Ample background information • Cycling protocol was programmed into cycle software • Semi- realistic environment • Thorough explanation of measurements • Invites more research on recovery and performance in endurance athletes

  44. Hoffman, J. R., Ratamess, N. A., Tranchina, C. P., Rashti, S. L., Kang, J., Faigenbaum, A. D. (2009). Effect of a proprietary protein supplement on recovery indices following resistance exercise in strength/power athletes. Amino acids, 38(3), 771-778. Effect of a proprietary protein supplement on recovery indices following resistance exercise in strength/power athletes http://www.eshop-healthcare.com/muscle-milk-high-protein-shake-mix/

  45. Objective • To evaluate the effect of pre and post exercise protein ingestion on recovery in resistance exercise

  46. Methods • Double-blind, randomized design. Participants were matched for strength • 15 male strength/football athletes • Supplement group consumed 42 grams of proprietary protein blend (“New Whey Liquid Protein”) pre and post exercise. • Placebo group consumed protein free beverage • Reported to a performance laboratory four different sessions (T1-T4)

  47. Methods • T1 - Athletes tested for maximum strength • T2 - Treatment consumed 10 minutes prior to exercise and 15 minutes post exercise. Blood samples taken pre and post exercise • Lower body resistance exercise was performed at 80% maximum strength • T3 & T4 - muscle soreness rating, treatment, resistance exercise, treatment, blood samples pre and post exercise

  48. Measurements • Soreness questionnaire • Blood samples to measure serum testosterone, cortisol, hemoglobin and hematocrit • Dietary recall

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