However, researchers from New Zealand found that caffeine consumption at a 3-6 mg / kg body weight level improved performance for most athletes. Of course, it is not that the standard intake of 6 mg is necessarily more effective than that of 3 mg. Some people who consume caffeine according to the lowest standard may have more significant effect than those who consume caffeine according to the highest standard.
So whats the effect of caffeine during exercise? In one study, participants were given 6% glucose, caffeine, or plain water for a two-hour indoor bicycle test. The results showed that athletes who consumed caffeine consumed 26 percent more carbohydrates than others. In other words, caffeine intake during exercise can increase the absorption rate of glucose and provide faster energy supply for working muscles.