Did you know that checking email, texts, or news on your smartphone or tablet before bedtime can wreak havoc with your sleep?

A pair of studies found that people who use their smartphones to check email after 9:00 PM have more trouble sleeping and feel “more tired and less engaged” at work the following day. The researchers cite two major reasons that explain this finding. First, the psychological reason: when you mentally engage with work problems before bedtime, your brain can have trouble winding down and relaxing to get to sleep. Second, the physiological reason: the “blue light” emitted by the smartphone’s screen has been found to disrupt melatonin production. In fact, blue light is the most disruptive to melatonin of all colors of light.

So to get a better night’s sleep – ditch the smartphone at least an hour before bedtime, and don’t check it until the morning.

Lanai, K, Johnson, RE, Barnes, CM. (2014.) Beginning the workday yet already depleted? Consequences of late-night smartphone use and sleep. Organizational Behavior and Human Decision Processes, May;124(1): 11-23.