Chapter 16 Ergogenic Aids for Fitness and Athletics

Ergogenic aids function By improving the capacity of the muscles and/or the oxygen transport and utilization systems to do work By removing or reducing inhibitory mechanisms to allow the use of previously untapped reserves Visit The Physician and Sports Medicine: Ergogenic Aids at

Amphetamines Mimics the activity of the sympathetic nervous system May improve swimming, running, weight throwing performance, reaction time, and balance, but conflicting results

Caffeine Central nervous system stimulant Diuretic Mental stimulant May impair motor performance Increases endurance performance in cycling, running, and swimming

Anabolic steroids Synthetic cholesterol-based drugs that resemble hormones Popular with strength and power athletes as well as body builders Increase strength, muscle mass, and body weight Visit NIDA Research Report—Steroid Abuse and Addiction at

Growth hormones A naturally occurring polypeptide secreted by the anterior pituitary gland Can now be synthesized Used by strength and power athletes to increase muscle size and strength

Sodium bicarbonate Naturally occurring buffer of acids in the blood Used to reduce fatigue-causing effects of lactic acid build-up

Creatine Synthesized primarily in the liver from amino acids Found in meat and fish Stored in skeletal muscle as phosphocreatine, used as a fuel source for high intensity exercise Creatine loading increases phosphocreatine stores in muscles to delay onset of fatigue in high intensity, short-term activities In resistance training it increases body weight, fat- free weight, and muscle mass Visit Creatine Supplementation at andwww.rice.edu/~jenky/sports/creatine.html Sports Science Creatine Review at

Pyruvate 3-carbon metabolite of carbohydrate metabolism Intermediate in glycolytic energy production pathway May provide additional substrate for the Krebs cycle, increase aerobic production of ATP, and improve endurance

Beta-hydroxy-beta-methylbutyrate (HMB) Metabolite produced from the breakdown of the amino acid leucine Used in resistance training to increase muscle mass and strength and decrease fat weight Being studied for effect on muscle damage from long-distance running

Phosphate loading Oral administration of sodium phosphate Potential ways it may affect performance –Elevations in serum and intracellular phosphate –Increased availability of phosphate for oxidative phosphorylation and creatine phosphate synthesis –Increased red cell anaerobic glycolysis and efficiency –Elevation in red cell 2,3-diphosphoglycerate (2,3- DPG) –Enhanced myocardial and cardiovascular efficiency –Possible increase in anaerobic threshold

Blood doping The process –8 to 12 weeks prior to an endurance competition, two pints of blood are removed. –Red blood cells (RBC) are separated and frozen –Athlete continues to train and body restores RBC count to normal levels –During week prior to competition, the RBCs are reinfused Results –An increase in RBC concentration and thus improved oxygen transport capability

Blood doping (cont.) Ethical questions surrounding blood doping –Con: increases performance in artificial and unfair manner –Pro: same advantage enjoyed by athletes who train at high elevations to compete at sea level

Erythropoietin Drug used for anemia and kidney disease Stimulates bone marrow to produce red blood cells (RBC) Improves performance is manner similar to blood doping

Carbohydrate loading Increases amount of glycogen stored within muscles and so delays the onset of fatigue during endurance activities Classic carbohydrate loading –15% carbohydrate for first three days and 70% for last three days Sherman’s moderate carbohydrate regime –50% carbohydrate for the first three days and 70% for the last three.

NNoneEnhances endurance performance Carbohydrate loading YElevated blood pressure, flu- like symptoms, possible heart attack, stroke, pulmonary edema Enhances endurance performance Erythropoietin YNone reportedEnhances endurance performance Blood doping NNone reportedConflicting resultsEnhances endurance performance Phosphate loading NMore research neededIncreases isometric strength, concentric and eccentric isokinetic peak torque, and fat-free weight Increases muscle mass and strength and decreases fat weight HMB NHigh doses: Gastrointestinal distress, diarrhea High doses improve submaximal endurance performance Improves performance in endurance activities, weight loss, lowers cholesterol Pyruvate AidAnecdotal effectResearch-proven effect Major side-effectsBanned