For many people, having a cup of coffee right out of bed is the best way to start a day. But a report from Asap Science says otherwise. It says the worst time for coffee is soon after we get up. When we wake up, our bodies start to make cortisol（皮质醇）. Cortisol helps us to think clearly and be quick to understand and act. The number of cortisol rises after we wake up and climb to the highest in about an hour. So there are two problems when we drink coffee during this time；⑴our bodies will make less cortisol, and ⑵the cortisol will make coffee less useful. And that's why some of us drink more and more coffee. The picture below shows how the cortisol levels rise and fall during the day.
Then, when's the best time to have coffee?Whenthe cortisol levels are going down, the report says. Cortisol levels are usually highest between8 a. m. and 9 a. m. ,between noon and1 p. m, and between 5：30 P. m. and 6：30 p. m. So if you want to have coffee, enjoy it after these times, and this popular drink will help you the most.
