Athletes sometimes turn to energy supplements to increase their ability to exercise more often. Common supplements to increase an athlete’s energy include: Caffeine, Guarana, Vitamin B12, and Asian ginseng. Caffeine, a common energy supplement, can be found in many different forms such as pills, tablets or capsules, and can also be found in common foods, such as coffee and tea. Caffeine is used to improve energy and increases metabolism. Guarana is another supplement that athletes take to enhance their athletic ability, it is frequently used for weight loss and as an energy supplement.A 2009 study from the University of Texas reports that caffeinated energy drinks decrease sporting performance. They found that after drinking an energy drink, 83% of participants improved their physical activity parameters by an average of 4.7%. This was attributed to the effects of caffeine, sucrose and Vitamin B in the drink – however scientific consensus does not support the efficacy of using Vitamin B as a performance enhancer. To explain the performance improvement the writers report an increase in blood levels of epinephrine, norepinephrine and beta-Endorphin. The adenosine receptor antagonism of caffeine accounts for the first two, while the latter is accounted for by the Neurobiological effects of physical exercise.Caffeine has been around since the 1900’s and became popularly used in the 1970’s when its power of masking fatigue became highly recognized. Similarly, the caffeine found in energy drinks and coffee shows an increased reaction performance and feelings of energy, focus and alertness in quickness and reaction anaerobic power tests. In other words, consuming an energy drink or any drink with caffeine increases short time/rapid exercise performance (like short full-speed sprints and heavy power weight lifting). Caffeine is chemically similar to adenosine, a type of sugar that helps in the regulation of important body processes, including the firing of neurotransmitters. Caffeine takes the place of adenosine in your brain, attaching itself to the same neural receptors affected by adenosine, and causing your neurons to fire more rapidly, hence caffeine’s stimulating effects.