03/20/2026
Does your sleep tracking data become a self-fulfilling prophecy?
Like, if your score is high, you feel more energized during the day and relaxed the next night where if you see a negative result, you feel tired and more grumpy?
Some really interesting studies have come out illuminating the subjective nature of how we feel we’ve slept.
In one study, participants were shown slightly altered sleep data - adjusted by only 5%. Those sleepers who were told their sleep was worse reported lower mood, felt less alert, and performed worse.The next night, these participants even woke up more often than the ones with the good data. In another study, insomniacs who were given more positive feedback than their actual data showed immediate improvements in mood, increased energy, and better subjective alertness. For either group, their sleep quality didn’t change, but due to the numbers they saw, their perception of it changed.
The placebo effect is real and powerful. Sometimes it’s helpful, but more often than not, people get hooked into their negative sleep score, which makes them feel worse. And then they start to worry about their sleep. And worry is the enemy of sleep! And then it becomes this feedback loop.
Sleep trackers can be useful but if you’re already worried about your sleep and putting a lot of thought and effort into how you’re going to sleep each night, my advice is to ditch the tracker. When you wake up, wait about an hour and then use your own judgement to measure how you feel - if you feel terrible, you don’t need a tracker to tell you that!
Where sleep trackers can be useful is when they’re being used as a trend tool to detect patterns over time. Instead of looking at your data each night, wait a week or two and notice if the quality of your sleep was impacted by the number of hours of sleep or exercise you got, caffeine or alcohol consumed, or other indicators.