A local researcher says one of the mistakes that people who have trouble sleeping often make is trying to “catch up” by sleeping in on their days off.

Dr. Sheila Garland of Memorial University says when someone loses sleep over the course of the week, they often think they can make up the difference on the weekend by sleeping in.

That can exacerbate the problem according to Garland, who says the time we wake up actually determines our bedtime. So sleeping in actually pushed bed time back, creating more problems sleeping heading into another work week.

She says most people require a certain level of sleep-pressure, that is the number of waking hours between periods of sleep.

For example, if a person needs seven hours of sleep and they wake up at 7:00 a.m., then they require 17 hours of sleep pressure, meaning they should fall asleep at midnight. If that same person sleeps in until 9:00, it will be 2:00 a.m. before they build up the required amount of sleep pressure. That means if they go to bed at midnight, they probably won’t be able to get to sleep.