1. Scott K. Powers Edward T. Howley Theory and Application to Fitness and Performance SEVENTH EDITION Chapter Copyright ©2009 The McGraw-Hill Companies, Inc. Permission required for reproduction or display outside of classroom use. Ergogenic Aids

2. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Outline  Research Design Concerns  Dietary Supplements  Aerobic Performance Oxygen Blood Doping  Anaerobic Performance Blood Buffers  Drugs Amphetamines Caffeine Nicotine  Physical Warm- Up

3. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Ergogenic Aids Substances or phenomena that are work-producing and are believed to increase performance –Nutrients –Drugs –Warm-up exercises –Hypnosis –Stress management –Blood doping –Oxygen breathing –Music –Extrinsic biomechanical aids Ergogenic Aids

4. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Research Design Concerns Amount of substance –Too little or too much may show no effect Subject –May be effective in “untrained” but not “trained” subjects, and vice versa –The “value” as determined by the subject Task –Endurance vs. short-term events –Large-motor vs. fine-motor activities Use –May enhance short-term performance but compromise long-term performance Research Design Concerns

5. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Research Design Concerns Placebo –Look-alike substance containing nothing that will improve performance –Athlete’s belief in a substance may influence performance Double-blind studies –Neither the investigators nor the subjects are aware of who is receiving the treatment Research Design Concerns

6. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Changes in Performance–The Placebo Effect Figure 25.1 Research Design Concerns

7. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  Ergogenic aids are defined as substances or phenomena that are work-producing and are believed to increase performance.  Due to the fact that an athlete’s belief in a substance may influence performance, scientists use a placebo or look-alike substance to control for this effect. In addition, scientists use a double-blind research design in which the investigator and subject are both unaware of the treatment. Research Design Concerns

8. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Dietary Supplements Little evidence that dietary supplements improve performance with the exception of creatine Despite this, 46% of athletes have used supplements Dietary Supplements Health Education Act (1994) –Legislated a lack of regulation of dietary supplements –Supplements may contain contaminants Anabolic steroid which could lead to positive drug test Dietary Supplements

9. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Dietary Supplements for Strength Trainers Dietary Supplements

10. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Dietary Supplements for Strength Trainers (continued) Dietary Supplements

11. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Creatine Monohydrate Increase muscle phosphocreatine (PC) –For short-term, explosive exercise Supplementation increases muscle creatine levels –20–25 g/day loading dose ~20% increase in muscle creatine –2–5 g/day maintenance dose 5 g/day appears to be safe for chronic consumption Improves ability to maintain force and power output Increase in muscle mass –Due more to water retention than protein synthesis Side effects –Some reported, but no long-term adverse effects Dietary Supplements

12. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  For the most part, there is little evidence that dietary supplements provide a performance advantage to athletes, with the possible exception of creatine. Dietary Supplements

13. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Aerobic Performance Oxygen Increases PO 2 of blood Hyperbaric chamber –Breathing air under higher pressure –21% (or higher) O 2 –No evidence of improved performance Endurance run on treadmill and weight lifting Increased %O 2 mixtures –Breathing >21% O 2 mixtures at atmospheric pressure –Improved time to exhaustion Throughout range of inspired %O 2

14. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Effect of PO 2 on Performance: O 2 Enriched Gas vs. Hyperbaric Chamber Aerobic Performance Figure 25.2

15. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Oxygen: Prior to Exercise Rationale is to “store” O 2 in blood –Cannot really increase O 2 bound to hemoglobin 97% saturated at rest (200 ml O 2 /L blood) Increased by only 3% (6 ml/L) breathing 100% O 2 –Can increase O 2 dissolved in plasma Dissolved oxygen increases from 3 to 21 ml O 2 /L blood 100 extra ml O 2 stored in blood –However, blood O 2 returns to normal within a few breaths of air Some evidence that O 2 breathing prior to exercise improves performance in short events –Must take place within 2 min of event –Not practical for athletes Aerobic Performance

16. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Oxygen: During Exercise Rationale is to prevent muscle hypoxia by delivering additional O 2 –Increase in O 2 content of arterial blood is balanced by decrease in blood flow to muscle –No real increase in oxygen delivery to muscle Only 2–5% increase in VO 2 max However, there is an increase in time to exhaustion –Beneficial in athletes who experience desaturation during exercise –High PO 2 slows glycolysis and reduces lactate and H + formation Not practical for use in performance Aerobic Performance

17. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Oxygen: After Exercise Rationale is to speed recovery and be ready for second bout of exercise Early results suggested it works –However, the subjects knew they were breathing oxygen Later research showed no benefit –No improvement in recovery HR, ventilation, or post-exercise VO 2 –No improvement in subsequent performance Aerobic Performance

18. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  Oxygen breathing before or after exercise seems to have little or no effect on performance, while oxygen breathing during exercise improves endurance performance. Aerobic Performance

19. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Blood Doping Infusion of RBCs to increase hemoglobin concentration and oxygen carrying capacity of blood –Autologous transfusion Uses subject’s own blood –Homologous transfusion Uses matched donor Effects of infusion of 900 ml blood –Increase [Hb] 8–9% –Increase VO 2 max 4–5% –Increase performance 3–34% Effects last for 10–12 weeks Aerobic Performance

20. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Changes in Hemoglobin Levels Following Removal and Reinfusion Aerobic Performance Figure 25.3

21. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Blood Doping Erythropoietin (EPO) –Hormone that stimulates RBC production –Part of therapy for chemotherapy or dialysis patients –Can lead to extremely high RBC Has led to death of athletes Testing for EPO use or RBC infusion –Hematological passport Tracks athlete’s blood over years to detect sudden changes Artificial oxygen carriers or Hemopure –Not shown to improve performance Aerobic Performance

22. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  Blood doping refers to the reinfusion of red blood cells in order to increase the hemoglobin concentration and oxygen- carrying capacity of the blood.  Due to improvements in blood storage techniques, blood doping has been shown to be effective in improving VO 2 max and endurance performance. Aerobic Performance

23. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Anaerobic Performance Emphasis on buffering H + released from muscle Blood buffers (sodium bicarbonate) –Enhances ability to buffer H + during exercise –Improves performances of 1–10 minutes duration or repeated bouts of high-intensity exercise No benefit for tasks of less than one minute –Optimal dose 0.3 gkg body weight –1 (with 1 liter of water) –Evidence of placebo effect in some studies –Large doses can lead to side effects Diarrhea and vomiting Anaerobic Performance

24. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  The ingestion of sodium bicarbonate improves performances of one to ten minutes’ duration or repeated bouts of high-intensity exercise. Anaerobic Performance

25. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Amphetamines Catecholamine-like effect –Sympathomimetic Cause increased arousal and perception of increased energy and self-confidence Improve performance in fatigued subjects only –No improvement in alert, non-fatigued subjects Drugs

26. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. A Closer Look 25.1  2 -agonists: Clenbuterol and Salbutamol Clenbuterol –Activates  2 receptors in airways to treat asthma –Anabolic agent 10–20% increase in muscle mass Type I to type II fiber conversion, hypertrophy of type II fibers –Used by athletes in power events (sprinting, football) Salbutamol –Inhaled  2 -agonist to treat asthma –Ingested, improves performance in supramaximal exercise Both are associated with severe side effects Drugs

27. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  Amphetamines have a catecholamine- like effect that leads to an increased arousal and a perception of increased energy and self-confidence.  While amphetamines improve the performance of fatigued subjects, they do not have this effect on alert, motivated, and nonfatigued subjects. Drugs

28. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Caffeine May improve performance at the muscle or nervous system, or the delivery of fuel to muscle Can elevate blood glucose and increase fat utilization Can decrease perception of fatigue and lower RPE during prolonged exercise Effect is variable and dose-related –Effect may be diminished in regular users Potential side effects –Insomnia, diarrhea, anxiety, irritability –Diuretic effect? Caffeine-ephedrine mixtures Drugs

29. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Factors Influenced by Caffeine That Might Improve Performance Drugs Figure 25.4

30. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  Caffeine can potentially improve performance at the muscle or in the central nervous system, or in the delivery of fuel for muscular work. Caffeine can elevate blood glucose and simultaneously increase the utilization of fat.  Caffeine’s ergogenic effect on performance is variable, and appears to be dose-related and less pronounced in subjects who are daily users of caffeine. Drugs

31. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Nicotine Smoking or chewing tobacco –Smoking leads to cancers and heart and lung diseases –Causes diseases of the mouth, including oral cancer and dental caries Can stimulate both sympathetic and parasympathetic nervous systems –Small doses increase autonomic activity –Large doses block autonomic responses Cardiovascular or GI effects –Increases in HR, higher RMR, increased cardiovascular responses to light exercise Drugs

32. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. The Relaxing and Stimulating Effects of Nicotine Drugs Figure 25.6

33. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  Nicotine has varied effects depending on whether the parasympathetic or sympathetic nervous system is stimulated. The use of smokeless tobacco can cause dental caries, gum disease, and oral cancer. Drugs

34. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Physical Warm-Up Causes both physiological and psychological changes that are beneficial to performance –Increased muscle temperature, arousal, focus on event Warm-up activities –Identical to performance –Directly related to performance –General warm-up Physical Warm-Up

35. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Recommendations Short-term performances (≤10 s max effort) –~40–60% VO 2 max for 5–10 min, followed by 5 min recovery –May reduce high-energy phosphates Intermediate-term performances (>10 s, ≤5 min) –~60–70% VO 2 max for 5–10 min, followed by ≤5 min recovery –Goal to begin performance with slightly elevated VO 2 Long-term performances (≥5 min) –~60–70% VO 2 max for 5–10 min –Too much may deplete muscle glycogen or increase thermal strain Physical Warm-Up

36. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. Stretching Increases joint flexibility Increases muscle-tendon compliance Reduces risk of injury –Little support in the literature –Stretching outside periods of exercise may reduce risk of injury –Stretching just prior to exercise does not Physical Warm-Up

37. Chapter 25 Copyright ©2009 The McGraw-Hill Companies, Inc. All Rights Reserved. In Summary  Warm-up activities can be identical to performance, directly related to performance, or indirectly related to performance (general warm-up). Warm- up causes both physiological and psychological changes that are beneficial to performance. Physical Warm-Up