Stimulant Effects of Caffeine

Caffeine is found in many of the plants that people commonly consume. According to Johns Hopkins Medicine, caffeine is the most commonly used mood-altering drug in the world.

Caffeine can be found in the following plants: coffee, tea, guarana, cola nut, cocao pod and maté.

According to the Mayo Foundation, caffeine stimulates the central nervous system. In most people, caffeine can be used to aid in the temporary alleviation of fatigue. Many people consume caffeine-containing foods, supplements and beverages because of its stimulant effect.

Alleviation of Fatigue

• Because of its stimulant effect, many people who work in professions or industries which require long hours use caffeine in order to fight fatigue. According to Johns Hopkins Medicine, studies show that caffeine disrupts sleep. When caffeine is ingested continuously throughout the day, fatigue and sleep onset may be delayed.

Concentration and Focus

• It is a widely-known fact that many students use caffeine to fuel their late night study sessions. While caffeine may aid in helping to keep those in academia awake, it also can have the added benefit of increasing concentration and focus. The stimulant caffeine has been shown to enhance the thinking process in many individuals. In an August, 2009 article that appeared on Newsday.com, Junaid Khan, who is a cardiac surgeon with Alta Bates Summit Medical Center in Berkeley, California said this about caffeine and mental performance: "So it's not that you're working faster or have an edge, you actually perform better because of the caffeine."

Athletic Performance

• Caffeine is believed to aid in athletic performance and endurance among athletes. While it does appear to aid in physical performance in some, too much caffeine can have a negative impact. Many energy drinks which are popular in the athletic community are high in sugar and caffeine content. This combination can act as a diuretic, according to Khan. Athletes who urinate excessively can become easily dehydrated. Dehydration leads to poorer athletic performance and could become a serious health issue if not treated promptly.

Use in Medications

• Caffeine consumption is associated with the treatment of asthma and headaches. It is also associated with a reduced risk of Parkinson's disease, according to researchers at Vanderbilt University's Institute for Coffee Studies. Many pain medications that are promoted for headache relief contain caffeine as an active ingredient.

Caffeine Sensitivity

• According to the Mayo Foundation for Medical Education and Research, there are individuals who are especially sensitive to the stimulant effects of caffeine. These people may experience negative side effects associated with caffeine intoxication after consuming small amounts. According to the Mayo Foundation for Medical Education and Research, 200 to 300 mg of caffeine per day can be ingested by most individuals without any ill effects. This dosage is equivalent to about 2 to 4 cups of drip coffee per day.

  Caffeine intoxication is an official clinical syndrome listed in the Diagnostic and Statistical Manual of Mental Disorders. Caffeine intoxication is also recognized by the World Health Organization's International Classification of Diseases.
  According to Johns Hopkins Medicine, the symptoms of caffeine intoxication can include: insomnia, rapid heartbeat, anxiety, nervousness, restlessness, gastrointestinal upset, tremors and in rare cases, death.

  According to the Mayo Foundation for Medical Education and Research, those who infrequently consume caffeine are most likely to experience negative side effects.