Researchers have found that the body does not really need caffeine in the morning. After waking up, our body produces a special hormone, responsible for vivacity, on its own. When a person wakes up the hormone enters the blood and signals awakening and physical activity, the person doesn't really need a cup of coffee to feel good. If you can't wake up without a cup of coffee, there is likely to be either nervous exhaustion or caffeine addiction. In any case, coffee is most effective to drink in the middle of the working day, when you are a little tired of work, and there is still a fairly long working day ahead of you. In this case, a cup of invigorating coffee will give you more strength and increase endurance and efficiency at work. If you constantly drink coffee only in the morning, by the middle of the day the invigorating coffee effect can end, and you will feel tired or sleepy. Drinking coffee after work late in the evening makes little sense because our body is exhausted and is preparing for sleep. Coffee consumption at night can contribute to insomnia, which will negatively affect the nervous system and your efficiency the next day.