Caffeine performance effects

Rusted, J., Caffeine and cognitive performance Effects on mood or mental processing Special Issue Caffeine research. Pharmacopsychoecologia 7(2), 49-54, 1994. 

Sawyer, D. A., Julia, H. L., Turin, A. C., Caffeine and human behavior Arousal, anxiety, and performance effects. Journal of Behavioral Medicine 5(4), 415-439, 1982. 

James, J. E., Gregg, M. E., Kane, M. Harte, F. (2005). Dietary caffeine, performance and mood enhancing and restorative effects after controlling for withdrawal reversal. Neuropsychobiology 52 (1), 1-10. 

Caffeine improves performance on tests of semantic memory, free recall, and recognition memory (Smith et al. 1994 Warburton 1995). However, the effects are both dose and task dependent. In some studies, higher doses produced greater improvement, while in others subjects receiving caffeine performed slightly worse than placebo (Loke 1988 ... 

A recent report by the Committee on Military Nutrition Research (81) recommended using caffeine doses of 100-600 mg to sustain the cognitive performance and physical endurance of military personnel, especially during periods of sleep deprivation. The Committee noted the fact that caffeine s effects appear particularly consistent in fatigued individuals. 

Caffeine s efficacy relative to pemoline and methylphenidate is unknown since side-by-side comparisons have not been performed. However, caffeine s effects are purported to be modest compared to those of amphetamine (100,126,131), and there is evidence that caffeine may be most useful for shorter... 

Source Adapted with permission from a table in Sawyer, 0. A., Julia, H. L, and Turin. A. C. (1982). Caffeine and human behavior Arousal, anxiety, and performance effects. Journal of Behavioral Medicine, 5, pp. 41 439 (Plenum Press) and in Kenny, M.. and Darragh, A. (1985), Central effeas of caffeine in man. in S. D. Iverson (ed.). Fsychopharmacology Recent Advances and Future Prospects, pp, 278-288 (Oxford University Press). Also adapted from information in Barone and Roberts (1996), Clementz and Dailey (1988). and Greden and Walters (1992). Up ted 2006. 

Caffeine is considered by pharmacologists to be a mild stimulant of the central nervous system. It has been shown to promote feelings of well being and increased abiUty to perform certain mental tasks efficiently. There are people who are oversensitive to the effects of caffeine overindulgence by these individuals, eg, intake of more than 600 mg caffeine/d, can bring unwanted effects such as anxiety, restlessness, sleeping difficulties, headache, or palpitations of the heart (54). 

Caffeine Effects on Psychological Functioning and Performance Barry D. Smith and Kenneth Tola... 

Somewhat of a dichotomy exists in the research literature pertaining to caffeine s ergogenic potential to enhance short-term, intense exercise. In general, laboratory research (in vitro/in situ) has consistently demonstrated positive results related to caffeine s ability to generate increased muscular force. Human studies have consistently been suggestive of no significant effects on short-term, high intensity performance. There have been a... 

A series of studies conducted in the late 1970s at Ball State University s Human Performance Laboratory by Costill and associates6163 has established caffeine as an effective ergogenic aid for the enhancement of endur-... 

Dodd et al.48 tested 17 moderately trained males for V02 max and time to exhaustion on a bicycle ergometer. Experimental trials involved the administration of 3- or 5-mg/kg caffeine 1 h prior to testing. Caffeine had no effect on exercise performance. Since nearly half of the subjects were caffeine naive (<25 mg/d), while the other half were caffeine tolerant (>310 mg/d), the researchers were able to conclude that even though caffeine had no significant effects on performance, it did produce a variety of physiologically significant effects (heart rate and expired ventilation volume) in the caffeine naive group. 

Perhaps the most intriguing perspective is that caffeine s major effects have little to do with muscles and fat metabolism but result from its psychostimulant effects, enhancing mood, improving attitude towards exercise, and thus motivating athletes to work harder and longer. This would account for its purported inability to alter strength, which may be a less psychologically malleable variable, while endurance performance is sometimes believed to be more amenable to force of will. 

Graham et al.79 noted that more than a quarter of Canadian youth surveyed reported use of caffeine during the last year to improve their athletic performance. The current allowable levels of caffeine permitted by the IOC are well above the minimum dose needed to elicit an ergogenic effect. If the IOC and other regulatory bodies are serious about controlling the use of performance enhancing drugs, then it may be necessary to ban caffeine entirely from competition. 

Powers, S., Byrd, R., Tulley, R., and Callendar, T., Effects of caffeine ingestion on metabolism and performance during graded exercise, European Journal of Applied Physiology, 50, 301, 1983. 

Dodd, S. L., Brooks, E., Powers, S. K., and Tulley, R., The effects of caffeine on graded exercise performance in caffeine naive versus caffeine habituated subjects, European Journal of Applied Physiology, 62, 424, 1991. 

Collomp, K., Ahmaidi, S., Audran, M., Chanal, J. L., and Prefaut, C., Effects of caffeine ingestion on performance and anaerobic metabolism during the Wingate Test, International Journal of Sports Medicine, 12, 439, 1991. 

Falk, B., Burstein, R., Ashkenazi, I., Spillberg, O., Alter, J., Zylber-Katz, E., Rubinstein, A., Bashan, N., and Shapiro, Y., The effect of caffeine on physical performance after prolonged exercise, European Journal of Applied Physiology, 59, 168, 1989. 

Sasaki, H., Maeda, J., Usui, S, and Ishiko, T., Effect of sucrose and caffeine ingestion on performance of prolonged strenuous running, International Journal of Sports Medicine, 8, 261, 1987. 

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