Early in my career as a sport psychologist, I used to tell my clients something that sounded both motivating and scientific: “It needs to become a habit. Like brushing your teeth — you wake up in the morning and just do it, without thinking.”
I probably said it in some television interview too. If you watched it — I apologize.
People nodded. The phrase made sense. If we can brush our teeth every morning without internal debates, why can’t we run the same way?
The problem is that this analogy is completely wrong. Not because people are lazy or lack discipline. But because sport and tooth brushing belong to different categories of behavior. Comparing them is like asking why you can’t learn German “like your mother tongue — you just know it, without thinking.”
Years later, after diving deep into the research on habit formation, I realized how misleading my advice had been. And how many people probably felt like failures because sport never “became like brushing their teeth.”
I. What Is a Habit — Really?
In psychology, a habit has a specific definition: a learned action performed with minimal cognitive effort. Not just “you do it regularly.” Not just “it’s no longer hard.” Your brain has automated the behavior to such a degree that it happens almost without conscious participation.
Think about tying your shoes. You do it every day, probably for 30 years. Can you describe the exact sequence of movements? Most people can’t — because the process has become so automatic that consciousness no longer participates.
Or brushing your teeth. You get up in the morning, grab the brush, apply paste, brush for about two minutes — and the whole time you’re thinking about the day ahead, breakfast, the 10 o’clock meeting. The act of “brushing teeth” itself doesn’t require focus. The body does it on autopilot.
Sounds simple, right? Anyone who has children knows it isn’t. Tooth brushing takes years to become automatic behavior — and this is one of the shortest and simplest things we learn. A two-minute action, the same place, the same sequence, a clear reward (clean taste in the mouth). And still — years.
These habits share common traits. They’re simple — consisting of a limited number of repeating movements. They’re short — taking minutes. The context is constant — same place, same time. And they don’t require decision-making during execution.
II. A Workout Is Not Just “Long Tooth Brushing”
Think about a regular run.
Even at first glance, “simple” running involves a continuous stream of micro-decisions. What’s my pace? Should I slow down on this hill? How do my knees feel? One more lap or enough? And if we’re talking about the gym — which exercises today, how many sets, how many reps, is this weight too light?
A workout is not a single action. It’s a complex sequence of multiple actions, each requiring some degree of attention and judgment. Even when following a program, you’re still adapting in real time: your body today is not the same as yesterday.
The more complex a behavior, the harder it is to make automatic. Research confirms this — simple, repetitive behaviors with clear cues and quick rewards (like flossing or drinking a glass of water) form strong habits. Complex behaviors like physical activity — not so much.
There’s also the question of duration. Brushing your teeth takes two minutes. A workout — at least 30-60 minutes. Psychologically, it’s impossible to maintain “autopilot” that long for an activity requiring physical effort and constant adaptation.
A study in PNAS used machine learning to analyze habit formation in two types of behavior: going to the gym and hand washing in a hospital setting. Developing a hand-washing habit took weeks. Going to the gym — months.
And the “21-day rule”? A complete myth, originating from a plastic surgeon in the 1960s. Dr. Maxwell Maltz noticed that his patients needed about three weeks to get used to their new appearance after surgery. Somehow this became “21 days for any habit.” Actual research shows between 2 and 5 months for relatively simple health behaviors. For something like regular exercise — even longer.
James Clear puts it directly in “Atomic Habits”: “There is nothing magical about time passing. It doesn’t matter if it’s been twenty-one days or thirty or three hundred. What matters is the rate at which you perform the behavior.” Habits are built through frequency, not time. You can do something twice in thirty days or two hundred times. Frequency makes the difference.
III. Two Kinds of “Habit” in Sport
Researchers haven’t given up on the idea of habits in physical activity. They’ve simply redefined it.
Psychologist Benjamin Gardner and his colleagues distinguish two types:
Instigation habit — the automatic decision to begin. A cue from the environment (end of the workday, waking up in the morning) triggers an impulse: “time to work out.” You don’t think about whether to go. You don’t weigh pros and cons. You just head out.
Execution habit — the automation of the workout itself. Doing the same exercises in the same sequence, without thinking about what comes next.
Research shows that the instigation habit predicts how often you exercise. The execution habit does not.
In other words: it doesn’t matter whether you follow the same routine at the gym. What matters is whether heading to the gym has become automatic.
Many beginner programs focus on an exact routine to follow — with the logic that repetition will build a habit. But the data say otherwise: you can have an instigation habit and try different types of exercises without losing the habit. Consistency is in the departure, not the content.
Allison Phillips, one of the leading researchers in this field: “Regardless of what type of exercise you’ll do on a given day, if you have an instigation habit, you’ll start exercising without having to think much or weigh the pros and cons.”
IV. What You Can Actually Automate
You don’t need to turn the entire workout into an automatic habit — something we’ve already established as nearly impossible. It’s enough to automate only the beginning.
And “the beginning” can be broken down into even smaller steps. Researchers speak of a “preparatory phase” — all the actions that bring you to a state of “ready to work out.” Putting on workout clothes. Packing the bag. Walking out the door. Getting in the car. Arriving at the gym.
Each of these actions is relatively simple. Each can be linked to an environmental cue. When the entire preparatory chain becomes automatic, the hardest part — the decision to train today — no longer exists as a decision.
Identify the cue. Which moment of your day can become a trigger? For many people, it’s the end of the workday — the moment they leave the office or close the laptop. For others, it’s waking up. The cue must be specific and consistent.
Link the cue to a specific plan. Not “after work I’ll train.” But “when I close my laptop, I put on my running shoes.” The first physical action, however small, breaks inertia.
A study from 2001 shows the power of this approach. Scientists divided participants into three groups. The first only tracked whether they exercised. The second received a motivational presentation about the benefits of sport. The third filled in one sentence: “Next week I will exercise on [DAY] at [TIME] at [PLACE].”
Result: 35-38% of the first two groups exercised at least once a week. From the third — 91%.
Motivation did nothing. The specific plan — everything.
Remove friction. Every additional step between the cue and the action is an opportunity for the brain to start negotiating. The bag is packed the night before. Clothes are laid out. The route to the gym is clear.
Leave the content flexible. Paradoxically, rigid adherence to the same workout can work against you. If you skip “leg day” and feel like you’ve ruined everything — that’s a sign you’ve automated the wrong thing.
Give yourself time — real time. Not 21 days. Research on new gym members shows a minimum of 4 workouts per week for 6 weeks for a basic habit. And that’s just the beginning.
V. Why This Is Good News
There’s something liberating about understanding that sport will never become like brushing your teeth.
It means you haven’t failed. You’re not missing some magical ability for discipline that others possess. Every time you go to a workout, you’re doing something that requires effort — and that’s normal.
An elite coach who worked with Olympians was asked what the difference is between the best athletes and everyone else. His answer: “At some point, it all comes down to who can tolerate the boredom of training every day, doing the same movements over and over again.”
Not magical motivation. Not turning the workout into something so automatic that you don’t feel it. But the ability to show up despite boredom, despite fatigue, despite not wanting to in this particular moment.
But it also means you can direct your energy more wisely. Instead of trying to automate something that by nature requires attention, you automate only the gateway — the moment of departure.
And then, once you’ve reached the track or the gym, you can be fully present. Make decisions. Adapt. Experience the effort consciously.
Brushing your teeth is a habit. Sport is a practice.
Both lead to lasting results. But through different mechanisms — and when you stop confusing the two, both become easier.
References
- Lally, P., van Jaarsveld, C.H.M., Potts, H.W.W., & Wardle, J. (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology, 40(6), 998-1009. https://doi.org/10.1002/ejsp.674
- Lally, P. & Gardner, B. (2013). Promoting habit formation. Health Psychology Review, 7(sup1), S137-S158. https://doi.org/10.1080/17437199.2011.603640
- Gardner, B., Lally, P., & Wardle, J. (2012). Making health habitual: The psychology of ‘habit-formation’ and general practice. British Journal of General Practice, 62(605), 664-666. https://doi.org/10.3399/bjgp12X659466
- Buyalskaya, A., Ho, H., Milkman, K.L., et al. (2023). What can machine learning teach us about habit formation? Evidence from exercise and hygiene. Proceedings of the National Academy of Sciences, 120(17), e2216115120. https://doi.org/10.1073/pnas.2216115120
- Phillips, L.A. & Gardner, B. (2016). Habitual exercise instigation (vs. execution) predicts healthy adults’ exercise frequency. Health Psychology, 35(1), 69-77. https://doi.org/10.1037/hea0000249
- Kaushal, N. & Rhodes, R.E. (2015). Exercise habit formation in new gym members: A longitudinal study. Journal of Behavioral Medicine, 38(4), 652-663. https://doi.org/10.1007/s10865-015-9640-7
- Gardner, B., Phillips, L.A., & Judah, G. (2016). Habitual instigation and habitual execution: Definition, measurement, and effects on behaviour frequency. British Journal of Health Psychology, 21(3), 613-630. https://doi.org/10.1111/bjhp.12189
- Milne, S., Orbell, S., & Sheeran, P. (2002). Combining motivational and volitional interventions to promote exercise participation: Protection motivation theory and implementation intentions. British Journal of Health Psychology, 7(2), 163-184. https://doi.org/10.1348/135910702169420
- Clear, J. (2018). Atomic Habits: Tiny Changes, Remarkable Results. Penguin Publishing Group.
- Arlinghaus, K.R. & Johnston, C.A. (2019). The importance of creating habits and routine. American Journal of Lifestyle Medicine, 13(2), 142-144. https://doi.org/10.1177/1559827618818044