THE RIGHT QUESTION - Smartphones and quality sleep don't mix. Professor Pierre Philip, a sleep specialist, offers guidance on how to use your device properly before bed.

81% of French people check their mobile phones before going to sleep , according to an Ifop poll conducted in January 2024. As early as 2019, the National Institute for Sleep and Vigilance recommended implementing a " digital curfew " before bedtime. And for good reason: screens, their content, and the blue light they emit disrupt sleep. To get back to peaceful nights, how long before going to bed should you stop looking at your phone?

At least 30 minutes before

To provide your body and brain with the ideal conditions for falling asleep , you should put your phone away between 30 minutes and 2 hours before bedtime, depending on your individual needs, explains Professor Pierre Philip, head of the sleep medicine department at the Bordeaux University Hospital. The goal? To avoid exposure to the blue light emitted by the screen, which disrupts the production of melatonin , also known as the sleep hormone. Melatonin levels rise in the evening—signaling to our brain that it's time to sleep—peak during the night, and drop around wake-up time. "Exposure to blue light can therefore delay the peak of melatonin secretion, causing sleep onset to be delayed," the doctor explains.

That being said, many options and software programs now offer the possibility of blocking blue light after a certain time, notes Pierre Philip, which reduces the risk of sleep disruption . “Ultimately, the question to ask isn’t so much ‘when to stop watching,’ but rather ‘what to watch?’,” he continues. “Studies reveal, in particular, that the nature of the interactions or the visuals we are exposed to can prevent us from reaching a state conducive to falling asleep.” If we read a novel or a somewhat dull article, we run little risk of staying awake. On the other hand, if we scroll through social media posts or watch a news report covering anxiety-inducing current events, we are more likely to experience repeated episodes of wakefulness, adds the doctor.

The question to ask is not so much “when to stop watching”, but rather “what to watch?”

Professor Pierre Philip, Sleep Specialist

Not forgetting that "smartphone notifications trigger an immediate cognitive reaction, creating an alert signal that disrupts sleep quality. I therefore recommend cutting off communication during the night by activating airplane mode, for example," comments Pierre Philip.

Once these precautions are taken, we ensure that all the conditions are right to help us fall asleep. Before bedtime, we opt for an early dinner and stop any intense physical activity 2 to 3 hours before going to bed. The closer we get to bedtime, the more we dim the lights in our environment. To relax, we can do some stretches or breathing exercises.