Having a well-rested, straight-thinking mind improves attention and focus, but it also blocks out weird - aka "creative" - thoughts that creep up after a night of little sleep. These thoughts should not be cast aside too easily, according to psychologist Ron Friedman, since they often provide us with the best ideas.
“It’s partly because, in order to be creative, sometimes you need to consider some ideas that don’t necessarily feel like they’re on track with what you're trying to achieve. And so having all these ideas come into your mind because you’re not quite as good at putting them off when you're tired can actually make you more creative.”
Based on this, Friedman suggests we plan our tasks for the day according to when we are most prone to feeling fatigued. For the majority of us this is just after lunch.
“Scheduling a creative task for a time in the day when you'll know you'll be a little bit tired can actually be beneficial,” he said.
“We are much sharper first thing in the morning, but by two or three o'clock we tire. We should take these fluctuations into account.”
It's not the first time the benefits of tiredness in a work setting have been shown – research in 2011 revealed how people's ability to solve riddles and maths problems improved when they were tired.
Being physically exhausted after a bout of exercise also improves work performance, according to Friedman, but in a different way.
“Most of us [exercise] to look good or feel good, but what most research is starting to show is that the strongest benefits are the immediate impacts on the way we think," he said.
“We get more blood flowing to the brain which enables us to focus better, and it activates memory regions of the brain to help us soak up information more quickly.”