Caffeine has an affect on performance, both physical and mental. The underlying mechanism pertaining to the way caffeine works in the body involves the central nervous system. Caffeine has specific effects that occur shortly after consumption.
Central Nervous System
Caffeine is a substance that is easily absorbed through the gastrointestinal tract. Then, it travels across the membrane of cells in the brain since it can easily pass through the blood-brain barrier. Because of this, the effects of caffeine are initiated within the central nervous system, according to an article in 2010 in the “Journal of the International Society of Sports Nutrition.” Since the central nervous system is involved with behavior, caffeine can affect physical performance-related areas–bearing in mind that the effects are on the neuronal level and not directly the muscle.
In addition to psychomotor, or movement-related abilities, caffeine also affects cognitive abilities such as alertness, memory and vigilance, according to an article on a study published in 2008 in “Medicine & Science in Sports and Exercise.” The study found that men who consumed caffeine performed better on tests that involve complex information processing. One such test was the Stroop test, which assesses how fast participants can ignore distractions and name a color word when it is presented in a color different than which its name denotes. For, example, the word “green” would be printed in blue or red ink, but never green.
During exercise, caffeine has an effect on energy consumption. When given 5 mg of caffeine for every 2.2 pounds of body weight, participants gained muscle strength in the legs when they engaged in a cycling task, according to a 2010 article in the “Journal of the International Society of Sports Nutrition.” Also, fat is burned in this process when the body uses energy from adipose, or fat cells, within muscle tissue instead of using food sources of fat from dietary intake. Therefore, when a person consumes caffeine and does cycling exercises, that fat that is more likely burned is stored fat in the body.
Caffeine also has an affect on running performance. For example, a group of 21 active men were observed to have faster sprinting speeds after consuming 5 mg of caffeine for every 2.2 pounds of body weight in a study published in October 2008 in “Medicine & Science in Sports & Exercise.” Overall, running times were reduced by 0.06 seconds, which marked a 1.4% reduction among the lowest times. Therefore, caffeine increased running speed. The researchers suspect caffeine to have positive effects with both single and multiple sprint sports.
- Journal of the International Society of Sports Nutrition”; International Society of Sports Nutrition Position Stand: Caffeine and Performance; Erica R Goldstein et al.; 2010
- “Medicine & Science in Sports & Exercise”; Caffeine Improves Physical and Cognitive Performance during Exhaustive Exercise; EEF HOGERVORST et al.; 2008
- “Medicine & Science in Sports & Exercise”; Caffeine Supplementation and Multiple Sprint Running Performance; Mark GLAISTER; October 2008