You’ve probably heard that it takes 21 days to form a new healthy habit—and then become frustrated when yours didn’t stick. Don’t get discouraged: That timeline is based on old, anecdotal evidence, say researchers at University College London. In reality, it probably takes closer to 66 days, or about 10 weeks, according to their study in the British Journal of General Practice.

So how can you make good-for-you behaviors become as automatic as brushing your teeth before bed? Follow this 6-step plan, developed with help from study co-author Benjamin Gardner, Ph.D.

Pick a tangible, realistic goal. If your goal is big—like losing weight or exercising more—narrow in on a single action that can help you get there, like going to the gym three times a week.
Fitbit tip: Set your goal in the Fitbit app—everything from hydration to activity to sleep to weight is possible—and track your progress.

Put a positive spin on it. Your goal should be a “do,” not a “don’t”: “When you’re trying to stop doing something unhealthy, the easiest way [to do that] is to replace it with something healthy,” says Gardner. “So instead of not eating popcorn every time you watch a movie, aim to eat fruit instead.”
Fitbit tip: Keep the positivity flowing by sharing your achievements in the Fitbit app. The kudos you get from other users can help keep you motivated.

Create cues. A good one is impossible to ignore. Planning to take a walk after lunch every day makes that midday meal your reminder to take action, says Gardner. Other examples include flossing right after you brush your teeth at night or refilling the water bottle you keep on your desk as soon as it’s empty.
Fitbit tip: Still having trouble remembering when to do your healthy habit? You can set up to eight silent alarms on most Fitbit trackers.

Nail the start. Say you want to start running in the morning. Yes, this entails putting one foot in front of the other thousands of times, but the very first step is to put on your running clothes, which in academic speak is called the “instigation.” Gardner says that once you make that habitual, the rest, or the “execution,” will naturally follow.
Fitbit tip: Invite friends to join you on your health journey by making a date to work towards your goals together. Put it in your calendar and set your Fitbit tracker or watch (Fitbit Alta, Alta HR, Charge 2, and Blaze offer calendar notifications) to alert you when the day arrives.

Be consistent. Every time you encounter the cue, do the action you’ve settled on. If you’re worried about getting bored, take heart: Gardner says you don’t have to do the same workout every time you put your sneakers on or follow the same route on every midday walk. “You should definitely vary your behavior,” he says. “Just keep the instigation habitual.”
Fitbit Tip: Check out Fitbit Premium for ideas on how to stay active and workouts.

Be patient. You should start to feel your healthy habit sticking after just two weeks, says Gardner, but like antibiotics—which you have to keep taking long after you feel better—a rock-solid habit takes about 10 weeks to fully develop, so keep at it even after it feels like it’s set in stone. Sixty-six days is the point at which your new healthy habit should be fully formed.
Fitbit tip: If you start to get frustrated, take a moment to recenter yourself. Doing a two- or five-minute guided breathing session on your Fitbit tracker can help reduce stress and anxiety.