Many of us want our morning coffee to give us our"get up and go." Altogether, the people of the world drink more than two billion cups of coffee each day .
Getting busy, getting tiredAdenosine is part of the system that regulates our sleep and wake cycle and part of why high levels of activity lead to tiredness. As we go about our days and do things, levels of adenosine rise because it is released as a by-product as energy is used in our cells. Laurits Regner Tuxen.Danish Artist, 18531927.Serving morning coffee, 1906. pic.twitter.com/PwftbbSyaQJanuary 22, 2023
So, the debt you owe the caffeine always eventually needs to be repaid, and the only real way to repay it is to sleep. Caffeine can also raise levels of cortisol , a stress hormone that can make you feel more alert. This might mean caffeine feels more effective later in the morning, because you already have a natural rise in cortisol when you wake up. The impact of a coffee right out of bed might not seem as powerful for this reason.