How long does it take to form a habit?
They found that healthful behaviors — things like eating more fruits and veggies and exercising regularly — take longer to become established than previously believed. But there was some good news too: Skipping a day or two here and there doesn’t have that much effect on whether or not the behavior eventually becomes a habitual part of an individual’s daily routine.
For the study, the researchers recruited 96 volunteers, aged 21 to 45. The volunteers were asked to choose a healthful eating, drinking or activity behavior that could be done in response to the same daily cue for 12 weeks, such as “eating a piece of fruit with lunch” and “running for 15 minutes before dinner.”
The volunteers were also asked to keep a daily log of whether or not they did the activity and to fill out a daily online questionnaire that tracked how automatic the behavior was becoming — whether, for example, they were engaging in the behavior “without thinking” or whether they’d find it difficult to not do the behavior.
The 82 volunteers who stuck with the study to its end took an average of 66 days for their chosen behavior to reach maximum automaticity. The individual range was wide, however, from 18 to 254 days. (Numbers longer than the 84 days of the study were based on a calculation that assumed the still-rising automaticity rate at the end of the study would continue.)
Most of the gains in automaticity occurred during the early days of repeating the behavior. In other words, at some point no amount of further practice was going to make the behavior feel more automatic.
Not surprisingly, the more complex the behavior, the longer it took to become habitual. Exercise behaviors (for example, a daily run) took about one-and-a-half times longer to form into a habit than eating or drinking behaviors.
But — and this is helpful to remember — missing an occasional day or two, even early in the adoption of the behavior, had little effect on whether the behavior became habit-forming.
This study has its limitations, of course. Most notably, the volunteers self-reported their data. Still, the study’s findings do suggest that we should give our attempts to develop healthful habits a bit more time than than the 21 days suggested by many self-help gurus. And if you miss a day or two here and there, don’t worry too much. Just keep at it. Eventually, perhaps even without even noticing, you may find the new behavior has become an automatic — and essential — part of your daily routine.