Caffeine is a central nervous system (CNS) stimulant that belongs to the Methylxanthine class. We all know that it is present in coffee. That is the reason why most of you stay awake when you drink a cup of coffee at night. Caffeine can also be seen in cocoa beans, chocolate, green tea, energy drinks, coffee-containing food like tiramisu, etc. Athletes have been consuming caffeine to improve their endurance performance. Caffeine is not prohibited by the World Anti-Doping Agency (WADA), but it is on their monitoring list.
Caffeine gets absorbed in the blood within 30-120 mins of oral intake after getting metabolized by the liver. There are three effects of how caffeine will help in performance.
The first and most well-researched effect is the ability of caffeine to block an adenosine molecule. Adenosine is produced in the body and it gives a feeling of tiredness, fatigue, and even pain by binding with its receptors in the brain. As caffeine and adenosine are structurally similar, the former binds to the receptors and stops the latter from getting attached to the same.
The second effect is the increased release of calcium from the muscle cells. Calcium molecules help in the contraction of muscles. Caffeine is said to increase its release and hence increase the force of contraction.
The third effect is that caffeine may help in fat oxidation. The triglycerides (the storage form of fat) are said to be broken down by caffeine and are used for energy. And hence the body uses less glycogen which is the storage form of carbohydrates in our body. It is also said that caffeine increases the production of a hormone called catecholamines which also breaks down triglycerides. Research in this direction is conflicting on whether a considerable amount of this, affects the actual performance.
A research study done to check the effect of caffeine on endurance performance stated that caffeine in moderate doses (3 - 6 mg/kg body weight) has a small but evident effect on endurance performance. One more research study was carried out to see the effect of caffeine on strength. It was reported that caffeine improved the maximal voluntary contraction strength, especially in the knee extensor muscle group.
Thus, in short, caffeine could potentially help athletes in their performance. The main mechanism is that the caffeine blocks the adenosine and decreases pain sensation and reduces fatigue. It also helps in increasing the alertness and reaction time of the athletes.
But having said this, overconsumption of caffeine will harm your body. There might be symptoms like nausea, vomiting, rapid breathing, anxiety, insomnia, etc. which will hamper your performance. So, you need to find the right amount of caffeine that works for you.