The caffeine in Matcha is high, however, it is released at a very steady and slower rate over time of about up to 6 hours. Therefore, it won't take you on a caffeine roller coaster ride and crash your blood sugar. It will provide a sustained energy boost. L-Theanine when mixed with caffeine, as in matcha, stabilizes your blood sugar so you don't feel shaky fro the caffeine, like you do from coffee. The combination of caffeine and L-theanine, makes you feel energized and focused, and at the same time, relaxed. You can kind of use it anyway you want. To relax, to relax and focus, to focus, or if you are training, your body will respond accordingly.