The hormone also restores balance after a stressful event, which means that you will be better able to settle down again after a high-pressure morning. If it occurred in the evening, it might play on your mind.
Repeated stressful events late in the day might also result in long-term health issues like obesity and type 2 diabetes, as well as depression, warns Yamanaka. “If you could avoid stressful events in the evening, you had better do stressful tasks during the morning.”
Find your afternoon peak
Cortisol levels might be higher in the morning to help us to better cope with early starts. “Not all people are more effective in the morning,” says Cristina Escribano Barreno, a psychologist from the Complutense University of Madrid. “Sayings such as 'the early bird catches the worm' bring to light that our working lives are oriented to the morning, so people who prefer the morning have an advantage.”
Being a morning or evening person is influenced by a lot of things: age, sex, social and environmental factors. Our bodies prepare us for the stresses of the day shortly after waking up – so while you have this chemical advantage, it is best to make the most of it.
However, for some tasks it takes our bodies a while to get up to speed. Performance in simple tasks like mental arithmetic correlate with the body’s core temperature – the higher the temperature, the better the performance.
Generally, our bodies are warmest in the early evening – so it might be best to put off simple mental tasks until then. This daily rhythm is controlled by our circadian clock, which means that our preference for rising early or late has a small effect on this pattern.
“In morning people this peak appears a bit earlier and in the evening people it appears a bit later,” says Konrad Jankowski, a psychologist from the University of Warsaw, Poland. “But generally this time difference is not striking – a maximum [of] a few hours.”