East Project Effects of Caffeine on Endurance Athletes Estella Nelson & Amanda Taylor April 25, 2007

1. East Project Effects of Caffeine on Endurance Athletes Estella Nelson & Amanda Taylor April 25, 2007

2. Linking Consumers Together with Caffeine Facts This study was done to recognize the knowledge, beliefs, and behaviors of physically active consumers in regards to effects of caffeine during performance.

3. A table of Contents • An Overview of Caffeine • Pharmacokinetics of Caffeine • Pharmacodynamics of Caffeine • Caffeine and Exercise Performance • Survey Results • Conclusion

4. An Overview of Caffeine • Caffeine is a CNS and metabolic stimulant • Ingested in many foods, beverages, supplements, and medications • Considered the most widely consumed psychoactive ‘drug’ • Most commonly used stimulant in sports • Major sources: • Adults= coffee (60-75%) and tea (15-30%) • Children= caffeinated soft drinks and chocolate • May cause insomnia and nervousness • High doses may cause medullary stimulation and convulsions • Caffeine=methylxanthine

5. Common Caffeinated Products

6. Absorbed after oral, rectal, parental administration, and through the skin Absorbed from G.I. Tract Peak plasma levels occur in 45 minutes to 2 hours resulting in high levels of energy Caffeine is then distributed in to body water The liver metabolizes caffeine to 3,7-theobromine, 1,3-theophyllline, and 1,7-paraxanthine Caffeine is then excreted in urine, saliva, semen, and breast milk The half-life of caffeine in healthy adults is 3.0 to 7.5 hours Pharmacokinetics of Caffeine

7. Pharmacodynamics of Caffeine • Caffeine effects the CNS, kidney, and cardiac and skeletal muscle as well as smooth muscle • Acts as stimulant towards the central nervous system • Inhibits an enzyme, has an antagonistic effect at central adenosine receptors • Binds to surface cells of adenosine receptors without activating them • Reduces adenosine activity and increases the activity of the neurotransmitter dopamine

8. Pharmacodynamics ofCaffeine • Effects- • G.I. tract (stimulates secretion of both gastric acid and digestive enzymes) kidneys (weak diuretic) cardiac muscle (bronchodialation) skeletal muscle (strengthens contractions) smooth muscle (reverses fatigue of diaphragm in patients with chronic obstructive lung diseases) • High doses results in: cardiovascular effects, arrhythmias, sinus tachycardia and increased cardiac output

9. Caffeine and Exercise Performance • Used as ergogenic aid-and is regulated by officials • Studies show an increase in performance in prolonged, endurance exercise but not during short term, high intensity activities • When evaluating the effects, take in to consideration caffeine naïve or caffeine tolerant • Naïve subjects- caffeine increases epinephrine output in proportion to dose

10. Graham, Hibbert, and Sathasivam (1998) recently found that caffeine ingested as capsules improved treadmill running by 31% compared to placebo Berglund and Hemmingsson (1982) studied cross-country skiing and found that performance increased as altitude increased with consumption of caffeine Another study (Spriet et al. 1992) of cyclists, single doses of caffeine consumed 1 hour prior to testing produced an increase in cycling time in recreational cyclists Nancy Clark states, “ Caffeine’s energy-enhancing effect is more likely related to its ability to make exercise seem easier. Through its stimulant effect upon the brain, caffeine may reduce the fatigue associated with long bouts of exercise…” Caffeine and Exercise Performance

11. Survey Results

12. Additional Results • Table 1 shows percent of male vs. female • Table 2 shows how active the clients are • Table 3 shows how the client’s perceive caffeine compared to exercise, and how many females vs. males • Table 4 shows what the client’s view on caffeine is

13. Conclusion • Caffeine is a commonly used stimulant in sports • Can be derived from many sources: • Food, energy drinks, supplements, and medications • Methylxanthines effect the central nervous system, cardiac and skeletal muscle as well as smooth muscle • Caffeine is metabolized by the liver in to 3 primary metabolites • Studies show caffeine has a positive effect on exercise endurance and performance. • Surveys conclude that the physical active consumer

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