How the 2-day rule changed my health forever

This simple principle will help you form great habits

Sam Duncan
2 min readJul 14, 2022

I’m sitting (slouching?) on a metaphorical pile of failed habits, from counting macros to writing 1000 words a day.

But there is one habit I have stuck to religiously, for years, without fail or exception:

I have exercised 3+ times per week for 14 years.

That might not sound impressive to you — but I’m proud of it.

Because despite what you might think if you saw my rusty road bike out the back, or that mouldy BJJ Gi in my cupboard, I’m not completely inconsistent.

In fact, I’ve learned a valuable lesson from those failed habits, the same lesson I learned from my consistent workout routine

It’s called the 2-day rule, and it’s backed by science.

Day one

You see, we so often make the mistake of thinking habits are all-or-nothing.

As best-selling author James Clear says:

“We assume that if we slip up on our diet, then we have ruined the whole thing; we act like missing one day of writing means we simply weren’t meant to be a writer.”

But the truth is that little mistakes — like missing a day of BJJ practice- don’t matter in the long run.

In fact, a study published in the European Journal of Social Psychology showed that skipping a day of a particular habit has no impact on your long-term ability to stick to the habit…

So long as you find a way to get back on track.

And that’s where the 2-day rule comes in.

Day two

I never miss 2-days of workouts in a row.

This wasn’t intentional initially, but over time, it became a rule to die by.

One day off - because I’m sick, or injured, or because I just don’t want to — that’s fine.

But there are no two days off. No matter what, there’s always a workout on the second day.

James Clear says it so well:

“One mistake is just an outlier. Two mistakes is the beginning of a pattern. Killing this pattern before it snowballs into something bigger is one reason why learning how to get back on track quickly is an essential skill for building good habits.“

Discovering this rule helped me understand why I never got my blue belt or completed that road bike race I started training for.

It’s because I let one mistake become two, and two mistakes become a pattern.

And suddenly a week off turned into another failed habit, another expensive hobby to throw on the discarded pile.

But discovering this rule also gave me confidence.

It made me realise that I can translate the habit of consistent exercise into other areas of my life.

I don’t miss two days of exercising — that works.

And now, I don’t miss two days of writing — and that works too.

Maybe I’ll get back on the bike, or don the Gi again.

And if I do, I’ll be sure to never miss two days in row.

Because it’s not all or nothing; it’s one day and then the next.