In today’s non-stop society, there is an increasing need for people to be awake and at work at all hours of the day. Extended work hours and night and shift work compete with the biological need to sleep and with daily rhythms driven by the biological clock.
According to a recent study by a group of researchers from Washington State University Spokane even small amounts of chronic sleep loss lead to increased sleepiness on the job, during the commute, and at home—jeopardizing productivity, safety, and well-being.
The time of the day at which an employee starts work affects both the duration and quality of sleep. As a result of this the researchers found employees demonstrated varying levels of concentration and alertness depending on the time they start work.
Employees who start their shift between 20:00 and midnight get the least amount of sleep, in contrast to those starting work between 09:00 and 14:00 who enjoyed the longest duration of sleep.
Angela Bowen who headed up the study said ‘ Our most interesting find was that shifts starting between 20:00 and midnight yielded consistently poorer predicted performance and less than adequate predicted total sleep per 24 hour period.”
She added: “Shifts of equal duration differ in how fatiguing they are depending on the time of day when they are scheduled. The same limitation on the number of duty hours may be either overly restrictive if during the day or too liberal if during the night.”