Sleep debt refers to the number of hours of sleep we are lacking at the end of each night. In other words, it is the difference between the ideal number of hours of sleep and the actual number of hours. These lost hours accumulate over the course of the week and represent our body’s sleep debt.
The average person is thought to get about eight hours of sleep in a 24-hour period. Based on this estimate, a person who sleeps seven hours each night would increase their daily sleep debt by one hour. This represents a debt of five hours from Monday to Friday. It is then tempting to try to “repay” this debt by sleeping in on the weekend.