According to studies conducted by scientists in Australia and Japan, our brains aren’t built to work a normal workweek. Instead, the limit is about 25 hours per week – especially if you’re over the age of 40.
After 25 hours, brain function starts to decline, making employees less effective and efficient. So instead of a five-day workweek, we’re talking about a three-day workweek. That sounds just about right. (Mel Magazine)