You probably thought too that energy drinks that contain lots of sugar can combat sleepiness, but a study conducted by researchers from the University of Loughborough, England say otherwise. “Whilst there is good evidence that sugar intake can boost physical energy, there is little support for it having any benefits for a sleepy brain,” says Professor Jim Horne, head of the Sleep Research Centre of the university. He explains that “sugar rush” provided by sweet drinks like Coca Cola and Lucozade keeps you alert only for about fifteen minutes. After a while, you start to get sleepy.

Professor Horne however noted that drinks high in sugar may be of help to people with low blood sugar. They are also good for athletes who engage in more physically demanding activities, adds Dr. Neil Stanley of the British Sleep Society. For many of us who have less taxing work, we should not turn to energy drinks with high sugar content and low caffeine just to keep us awake after a long day’s work. This is especially advisable to drivers who need to be alert all the time. Experts recommend drinks with “useful amounts of caffeine” coupled by a catnap.