Humans have a well-defined internal clock that shapes our energy levels throughout the day: our circadian process, which is often referred to as a circadian rhythm because it tends to be very regular. If you’ve ever had jetlag, then you know how persistent circadian rhythms can be. This natural — and hardwired — ebb and flow in our ability to feel alert or sleepy has important implications for you and your employees.
Although managers expect their employees to be at their best at all hours of the workday, it’s an unrealistic expectation. Employees may want to be their best at all hours, but their natural circadian rhythms will not always align with this desire. On average, after the workday begins, employees take a few hours to reach their peak levels of alertness and energy — and that peak does not last long. Not long after lunch, those levels begin to decline, hitting a low at around 3pm. We often blame this on lunch, but in reality this is just a natural part of the circadian process. After the 3pm dip, alertness tends to increase again until hitting a second peak at approximately 6pm.
via The Ideal Work Schedule, as Determined by Circadian Rhythms – HBR.
