Here are a few of the questions I had about caffeine:Does caffeine enhance athletic performance? Maybe yes, maybe no. It's not that easy of a question to answer. Caffeine has a lot of effects. It does stimulate the central nervous system and metabolism, and it may reduce fatigue. As such, caffeine is considered by many to be ergogenic ("enhancing physical performance"), but if this were true, then you would think that caffeine would be a banned substance. Is caffeine banned at the Olympics? No, not at the present (2009). Caffeine used to be banned, or at least its use restricted, by the International Olympic Committee, but this restriction was lifted in 2004 when the World Anti-Doping Agency (WADA) removed caffeine from its list of banned substances. There were several reasons for this decision, not the least of which is the controversy as to whether in fact caffeine is ergogenic. Some research has in fact indicated that caffeine may be performance-decreasing above the 12 microgram/ml urinary threshold that was previously used for Olympics testing. Another factor in the WADA decision was the difficulty of banning caffeine totally, since caffeine is almost ubiquitous in beverages and foods (think chocolate!). Since the ban in 2004 the WADA has been monitoring the use of caffeine in order to detect any pattern of misuse in sport. Anyway, since caffeine use is allowed at the Olympics, you would think that it is a legal substance in all sports. Is caffeine banned by the NCAA? Not exactly, but the in 2006 the NCAA (National Collegiate Athletics Association) restricted the intake of caffeine by setting a urinary cut-off level of 15 micrograms/mL. It is difficult to estimate how much caffeine would have to be consumed to surpass this threshold. Drinking about 8 cups of coffee (with 100 mg caffeine in each cup) within one hour would approximate this level in most adults. Can too much caffeine kill you? Ignoring drug interactions and heart arrythmias, death caused purely by an overdose of caffeine does happen, but is quite rare. It would take the ingestion of between 70 and 100 cups of coffee in a limited time to reach fatal levels. Drinking this amount of coffee in a short period of time would seem to be quite difficult, but that amount of caffeine has been consumed by ingesting caffeine pills. Finally it is interesting to note that the toxic dose of caffeine for adults (150 milligrams per kilogram of body weight) is the same toxic dose for dogs. Since most dogs weigh less than most people, it takes less caffeine to be toxic. That is one reason not to feed chocolate, which contains caffeine, to dogs. Another reason is that chocolate also contains theobromine, which is similar to caffeine. Humans can break down theobromine into a non-toxic compound much more effectively than can dogs. There are varying amounts of theobromine in different types of chocolates, but it only takes about 1 square of unsweetened chocolate for every 10 pounds that a dog weighs to be toxic.