What you need to know to build healthy habits that stick

It’s nearly October. New Year’s resolutions are long-forgotten. But unlike ambitious goals or brave resolutions made on January 1, healthy habits that stick last all year long. Little habits like regular exercise, eating more fruit and veggies, keeping your inbox closed while you work, and leaving work on time each night add up to create a more healthy, productive life overall.

But it’s easier said than done. Building healthy habits that truly stick and don’t wane over time is tough. Knowing what works, what doesn’t, and how long the process will take can set us up for success, whether we’re building habits to help us get more work done, spend more time with our families, or just get out of the office more.

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21 days is a myth: There’s no set time span for building a habit

Many of us have heard that it takes 21 days to build a habit. But the truth is, not only is 21 days a made-up figure, there’s no specific time span required to build a habit. Making a behavior truly automatic takes a different amount of time depending on the person and the behavior. It might even differ based on other variables like timing, how busy you are, or other habits you’ve already built.

A study of 96 people from University College London in 2009 followed habit formation in each participant. Each day, participants were asked how automatic the behavior had become, and whether it could be done without thinking.

On average, behaviors became automatic after 66 days. But there was plenty of variation among participants, ranging from 18 days right up to 254. The study found some people took a long time to form their habits, and that different habits required longer to become automatic.

But not all habits are created equal. Some habits can have a cascading effect on the rest of your life, your choices, and even help you to build more habits on top of them. These are known as keystone habits, and are a great place to start if you’re trying to make a change that will stick.

Keystone habits create a cascading effect

When you learn about keystone habits, it’s hard to believe they’re not magic. Although they still take time and effort to build, keystone habits have a strange effect on us, where they encourage us to build other healthy habits without trying.

Here’s how Charles Duhigg, author of The Power of Habit, explains keystone habits:

When researchers look at how people change their habitual behaviors, they find when some changes occur, it seems to set off a chain reaction that causes other patterns to change as well. For some people, exercise is a good example of this. When you start exercising habitually, according to studies, you start eating more healthfully.

There are more benefits, too. For many people, building an exercise habit makes them procrastinate less at work, do their dishes earlier, and even use their credit cards less often.

It seems to be evidence that for many people, exercise is a keystone habit. Once you start to change your exercise habits, it sets off a chain reaction that changes other habits as well.

But exercise isn’t the only keystone habit. Keystone habits are different for everyone—exercise is just a common one. The trick to finding your own keystone habit, according to Duhigg, is to find one that changes how you think of yourself:

The power of a keystone habit draws from its ability to change your self image. Basically, anything can become a keystone habit if it has this power to make you see yourself in a different way.

Another example of a keystone habit is making the bed every day. Though it seems like a small habit, this has been shown to correlate with higher productivity, more success at sticking to a budget, and even a greater sense of well-being.

If making your bed makes you think of yourself as a more conscientious person, it may be enough to cascade into other healthy behaviors.

Whatever it is you want to improve about your life, look for a habit you can form that will change how you think about yourself, in a way you’d be happy with. That’s the place to start when building habits, because other related behaviors may just fall into place once that first keystone habit has been built.

3 ways to make a new habit stick

Once you’ve chosen the habit you want to build, there are a few key strategies to keep in mind. Building a habit is a long, tough road, but you can make it easier and give yourself a better chance of success if you approach it the right way.

Schedule it

How many times have you made a plan to start going to the gym or eating healthy or spending more time with your family, only to not even get started? Most of us fail to capitalize on our initial motivation and enthusiasm for building a new habit because we don’t make a plan.

Without a plan, following through on a vague idea of exercising more or spending more time with the people we love is almost impossible. But having a plan can make a huge difference to our ability to get things done.

One study of college students proved this when the researchers tried to convince students to get a tetanus shot. Some students were given information about tetanus and shown gruesome photos of what could happen if they didn’t get vaccinated.

These students were motivated to get a tetanus shot, but few of them actually did so.

For another group of students, the researchers took a different approach: they helped the students form a plan to get their shots. Here’s what happened:

A portion of students received a detailed plan on how to get to the medical clinic; they were told the times when shots were available; they were given a map with the clinic clearly circled; and they were asked to review their schedule to find a time. Of the students who received this detailed plan, 28 percent went to get a shot, compared with 3 percent of students without the plan.

So before your motivation to build a new habit dissipates, make a plan. Schedule your workouts on your calendar. Set an alarm to remind you to leave work on time to get home for dinner. Pack a piece of fruit with your lunch the night before, so you don’t have to think about taking it to work with you.

Make a plan for how you’ll complete your habit, and you’ll be much more likely to do so.

Make it easy

While making a plan goes a long way toward building a new habit, it won’t help much if you’ve chosen a habit that’s incredibly difficult.

A good example of how important it is for your habit to be easy to complete is a report on over 7 million people in the U.S. from the marketing consulting firm Dstillery that found people who go to the gym regularly tend to travel four miles or less to get there. For those who traveled around four miles to the gym, they tended to go roughly five times per month, whereas those who had a longer gym commute only went once per month on average.

Making your habit easier to complete reduces the effort needed in the early stages, before it becomes automatic. The University College London researchers who studied how long it takes for a habit to form also found that earlier habit practice is rewarded with greater increases in how automatic the behavior becomes.

So finding ways to make your habit easy to do when you’re getting started could have the biggest gains in getting you closer to doing it automatically.

According to BJ Fogg, who runs the Stanford University Persuasive Tech Lab, we should design our habits with “Minimum Viable Effort” in mind:

Make it tiny. To create a new habit, you must first simplify the behavior. Make it tiny, even ridiculous. A good tiny behavior is easy to do — and fast.

Rather than going all out with an ambitious habit like running five miles per day, Fogg suggests starting with the tiniest behavior you can do that still counts as completing your habit. Maybe that just means putting on your running shoes and going out your front door. Don’t even make yourself run at first—just start by making it a habit to get out the door with your running shoes on.

Chances are, most days you’ll end up doing more than that tiny amount. But for the days when you can barely dredge up any motivation, keeping your habit so tiny it’s ridiculous means you’re more likely to complete it. And those early successes are critical to eventually building a habit that’s automatic.

Of course, you’ll want to slowly ramp up the behavior—so eventually you’ll make running around your block the minimum required, and then running half a mile, until eventually it’s automatic and easy to run five miles, three times per week. But the key is to start tiny, and build up slowly.

Then again, since we have more motivation to build a habit when we’re starting out, perhaps starting tiny isn’t always the best approach.

Try an attack dose

Mark Bao, former research assistant at the Center for Decision Sciences at Columbia Unversity, suggests an alternative to starting small and ramping up slowly. He calls it “attack doses.”

The idea is to capitalize on the high levels of motivation and willpower we tend to have when starting out with a new habit. Many of us have been through this experience: we set a New Year’s resolution or plan to start a new healthy habit, go all-out for the first few days, but then start to drop off in intensity, start finding it harder to be motivated, and struggle to maintain the habit over time.

Bao suggests we capitalize on our initial motivation by going all-out initially, while also having a plan for dropping off in intensity. The reason Bao suggests this can work is because it addresses a gap that exists when we’re trying to build habits: on the one hand, we know we should exercise. But on the other hand, we don’t feel like it, or it seems hard and painful. There’s a gap between what we should do (or want to do, in the long-term), and what we want to do in the short-term.

According to Bao, building a habit comes down to closing that gap:

The goal of sustainable habit development is to build instinctual evidence —such as seeing results, weight loss, better health, etc.—so that “how much you know you should exercise” matches “how much you want to exercise”.

And attack doses is a way to build that instinctual evidence quickly. By doing the most intense form of our new healthy habit while we have the motivation to do so, we can quickly develop instinctual evidence. From working out regularly for a couple of weeks, we might start to see gains in strength, weight loss, mental clarity, and enjoyment of using our bodies. If you start out with a tiny habit like just putting on your running shoes and stepping outside, it’s going to take a long time before you build any instinctual evidence that exercise is beneficial. I know for me, it’s important to see verifiable gains of some kind quickly, if I’m going to stay motivated for long enough to make a new behavior completely automatic.

The key to making an attack dose work, however, is to plan for the inevitable drop-off of motivation. Life gets in the way, we sleep poorly and don’t have the energy, or we just can’t be bothered sometimes. These things will happen, and we need to be prepared:

Make no mistake: during the attack dose period, the prospective habit is highly volatile and not at all stable nor sustainable. As a result, we need to predict that these things will happen, and plan to relax the habit intensity over time to more sustainable levels.

But knowing that we’ll run into these issues can help us prepare for them. Bao suggests planning to drop off after an attack dose to a very small version of your new habit, and slowly ramp up again to the level of your initial attack dose. If you start by going to the gym for an hour, for instance, after a week or two you might drop down to just 15 minutes, and add ten minutes at a time until you’re working out for an hour again.

This process is very similar to BJ Fogg’s “start tiny” approach, only it begins with an attack dose to increase the instinctual evidence that will hopefully motivate us through the slow ramp up period.

Habits, especially the early days, are highly vulnerable to disruption, and we need to build resilience to disruption, which is one of the goals of using small steps for sustainable habit development. Habit resilience is what can allow us to continue developing a habit even when we’re facing challenges, like missing a day, but if we don’t have the resilience, failing to make good on a habit one day may unravel the entire habit.

Bao believes an attack dose that gives us a big hit of instinctual evidence up front can help us build the resilience we need to get through the tough times as we slowly build a new habit.


Whether an attack dose or a tiny habit is the best way to start will depend on you, and the particular habit you’re trying to build. But either way, it’s key to make a plan, and to ramp up slowly over time—adding a little more effort each time, and building instinctual evidence of the benefits as you go.

And if you’re building a keystone habit, you may just find lots of other healthy behaviors start falling into place once that first habit becomes automatic.

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Belle B. Cooper

Belle is an iOS developer, writer, and co-founder of Melbourne-based software company Hello Code. She writes about productivity, lifehacks, and finding ways to do more meaningful work.

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