Wearing a fitness tracker or smartwatch might be harming your sleep, according to experts. The devices can cause orthosomnia, a condition defined in the journal Nature and Science of Sleep as “the obsessive pursuit of optimal sleep metrics based on fitness tracker or mobile phone data”.
Dr Andy Galpin, a human performance scientist and co-founder of sleep optimisation company Absolute Rest, says trackers can give a good idea of sleep duration but often provide inaccurate data on sleep quality. “These are non-medical devices that are not accurate and they’re not actually depicting sleep quality,” he warns. Poor feedback from such devices can lead people who sleep well to believe they have a problem, fuelling orthosomnia.
Dr Galpin advises a tech-free method to measure sleep quality: how you feel the next day. “If I wake up feeling fully refreshed, I’m sharp, my energy is awesome… I don’t really care what a fitness tracker says,” he explains. He adds that feeling drowsy in the early afternoon is normal and desirable, as it builds sleep pressure for the night.
For those struggling with sleep, Dr Galpin co-authored a 2025 paper in Lifestyle Medicine listing environmental factors that affect sleep, such as noise and light. The paper recommends earplugs for noise-sensitive individuals, noting that existing research does not support noise machines. Consistent sleep timing and regularity are also crucial, he says.
