The 90 Day Challenge changed my life.

When I started using it, in July of 2014, I had never heard of 90 days being used for habit change.

I later discovered I’m not the only one who discovered the power of it.

I’d heard of 30 day challenges, of course. They can be fun, short monthly sprints to try out something new. They’re a good frame to help you start doing something that you know you should do every day, but just can’t bare the commitment to doing it every day for the rest of your life. You know you can do almost anything for 30 days in a row, if you really knuckle down. The end date gives your brain a rationalisation for continuing with the pain of changing habits. “Just 20 more days, that’s all, then I’ll inhale all the cupcakes I want.”

Problem was, 30 days had never changed my life before. I’d tried going without alcohol for 30 days, for example, and it was a grind. I didn’t last the full duration, but if I had, I don’t think I would have really changed on a neural level by the end of it. I’d still be “gagging for a pint”, and the taste of it on day 31 would be unforgettable, and throw me right back into my old ways.

30 days isn’t enough.

But if I couldn’t do 30 days of a simple behavioural change, (and 30 days is not enough), then what’s the chance I’d be able to last for as long as necessary?

The chance is pretty high, as it happens.


What Pushes Someone to Take on a 90 Day Challenge?

I was fiercely dissatisfied with myself.

I had spent years trying to improve myself, to build an income through my own grit and determination, while also trying to eat better, get better with the ladies, get more organised, get better at keeping in touch, and on and on.

When I looked back 3 years in my journal, I could have wept at how identical my problems and goals were back then. Nothing had changed in my life but the location.

One day, I went into surgery to get my clavicle re-attached to my scapula after two years of living with a pointy shoulder, and during the recovery period I went back to live with my parents.

The pain of the slowly recovering shoulder encouraged me to be lazy, and I was already pretty lazy. The drive that pushed me to strike out on my own right after university had been gradually fading for months. Now it hit an all-time low, I didn’t know how to drag it back. Whenever I tried to develop my [blank] or optimise my [insert aspect of life], all other blanks and aspects slipped back. It felt like rolling several stones up a hill. I wanted to improve everything in my life at once.

And I had never been so stagnant in all my life.

So I stopped.

And I pondered.

I realised that my current priority was not hacking my sleep or being a dating demon or anything other shiny distraction. It was money. My career was all but dead.

I asked myself a simple question:

“If ALL areas of my life fell to shit, what would be the one habit that, if I kept to it religiously, I would still make progress in my career?”

I heard nothing back, so I added some colour to it:

“If I woke up one day surrounded by cheap hookers and spilt cocaine, with a huge belly under my nipples and no friends to speak of, what habit would STILL force me to roll out of bed, comb my wisps of hair, and get on Skype to talk to a client?”

I heard something back.

“If you wrote down a list of important tasks every day, and every day you crossed off everything on that list, then you would always make progress.”

It was a little simplistic, and since then I’ve refined the thinking (see below), but it was the perfect place to start.

Thus, I had focus. One habit I needed to worry about, and no others.

Now, how was I going to install it into my mind?

I’d tried 30 day challenges before, but as I said, they never seemed long enough to drill it in properly. I wanted to literally change my neural pathways.

“What would ensure the habit is solidly implanted for good?” I wondered to myself.

How about… 90 days in a row?

And so I opened up a notebook, and I wrote down:

Day 01 [ ]

Day 02 [ ]

Day 03 [ ]



By the time I got to Day 43, it was beginning to dawn on me just how long 90 days really is.

It’s fucking long!

And that only fuelled me with more hope.

There was no way I could get to the end of 90 days without being a changed man. No way.

Here’re two screenshot straight from my journal back then, unedited for your voyeuristic pleasure:

I made it to the end of the challenge, with some important lessons learned.

From this, and from my subsequent challenges, as well as the experience of a friend of mine who was inspired to start his own 90 Day Challenges, I developed a list of guidelines that, if followed, essentially ensure that your life will be changed for the better.

Sound good?

The 90 Day Method

One By One

One habit at a time.

A single habit might include a number of parts to it. Some necessarily will. But limit it down as much as possible.

Only choose the most exciting habit to you at the present time. Maybe it’s been burning within you for a while. Those are usually better than just-heard-of things.


MVD: Minimum Viable Day

Set a lower limit for what constitutes a “successful day”, and be as specific as you can be.

Make it LOW.

During my Miracle Morning Challenge, my MVD was 1 minute given to each of the 6 morning routine components. If I did that, I got to colour in the day’s box.

TA: Target Average

You don’t want to wind up just barely scraping by.

The One By One rule should ensure you’re genuinely excited about what you’re doing, and confident in it’s importance, but why not make your target more specific than “more than the minimum”?

If your MVD is to read one page of a respected business book, for example, then your TA could be to read seven pages.

If you don’t reach your TA for whatever excuse (busy, depressed, kidnapped by terrorists), then you’ll fall back on your MVD.

MDE: Maximum Daily Effort

Don’t over-do it.

Even if you feel like it.

Wise old strong-men of the early 20th century used to talk about “putting strength in the bank” or “milking a program”, which meant they always held a little bit back for the next work-out. I learned about this from the excellent book Convict Conditioning.

Fans of Body by Science or The Four Hour Body might take issue with this, as rapid muscle growth is supposedly only triggered when you reach total muscular failure.

In reality, it’s just the quickest way to bulk up.

But your ligaments and tendons don’t develop as fast as your muscles.

Pushing as hard and fast as possible leads to stories like the one Tim Ferriss told on Joe Rogan’s podcast, about a massive brick-house-body guy he knows, Scot Mendelson, who tore his entire quadricep while squatting one day. (See 1:15:20)

“Ouch” doesn’t even begin.

It seems he was so strong, his own tendons couldn’t keep up!

Minor sprains from over-zealous wanna-be strong-men are more common, and in the world of habits, a “sprain” is when you collapse one day and dive much deeper into your old behaviour than you ever would have normally. It’s amazing how many crisps you can eat when you’ve been avoiding them for weeks, isn’t it?

Don’t over do it.

Define your MDE, the maximum amount of effort you’ll allow yourself to exert on good days.

Keep some strength in the bank for tomorrow.


Deliberate Leniency

This is not the same as your definition of a Minimum Viable Day.

Deliberate Leniency is where you choose a very specific way to “let yourself off the hook”, such that you will be free to push yourself to your Maximum Daily Effort as often as possible.

For example:

My first challenge, The Assignment Challenge, didn’t have any deliberate leniency. If I didn’t cross off what I had written down to do, then I failed.

This lead to me setting very easy tasks to ensure success.

So I made a 2.0 upgrade. It was a total restructure, but preserved the original purpose.

The Work First Challenge didn’t require that I completed the tasks. Only that I would work on them first, before starting anything else on my laptop.

The “deliberate leniency” came in at 5pm, where I would let myself off the hook. There are a lot of things in our lives that aren’t proper “tasks”, and I wasn’t prepared to completely ignore a text message from a friend the entire day, just because I underestimated the time a particular task would take.

Build in some specific parameters that will let you off the hook just before you crack and fail the challenge.

Magically, the challenge will be easier to sustain without making the daily behaviours any softer.


The 30 Day Overlap

DON’T add more than ONE new 90 Day Challenge every 30 days!

See below for more on why this is so important, but in summary, this allows you to focus your precious willpower only on what’s important, and make success much more likely.

By the time you reach day 30 of your first challenge, you’ll feel it getting easier, and you can safely add another.

Warning: You WILL feel like adding another challenge sooner!

This shit is exciting, especially if you haven’t made much progress recently.

Whenever I’ve broken this rule, I’ve failed a challenge, even though each time if felt like such a good decision. I was succeeding, so why not pile on even more success??

It’s a trap!

Earlier I mentioned a friend of mine who was inspired to start his own 90 Day Challenges, and that he helped me develop these guidelines.

We were living together at the time, living away from our home country and both equally excited about self-improvement across all main areas of our lives.

He added a new challenge every week. I advised him against it, but it was too exciting to resist.

I don’t think he ever finished a 90 day challenge.

Keep some strength in the bank, people!

Follow the 30 day overlap.


The 90 Day Philosophy

Step-by-steps are more sexy than general principles, but both are essential, so skip this section at your peril.

Prioritisation by Force

You’re not going to do something for 90 days if, in the back of your mind, you doubt it. Particularly if it’s difficult.

The 30 Day Overlap rule is there to stop the VERY common mistake for people like me (and probably you) who tend to get a little over-zealous when doing something like this.

With my first challenge, I wasn’t thinking about doing more than one, so I really focused in and chose the highest leverage habit I could imagine (at the time).

After 30 days of crossing off all my to-dos every day, it started to get easier. It wasn’t yet “burned in”, but it was getting easier. That’s when I started my no-alcohol challenge.

Later, I tried adding a new challenge every week. Three weeks in, I had five overlapping challenges all going at once. It was ridiculous, and I was forced to re-prioritise, dropping all but the most important.

I’m sure 12 simultaneous 90 day challenges could be possible (the number you’d wrack up with one addition per week), so long as they were teeny tiny habits, or if you used all the motivation techniques known to man, but I would suggest that it’s not worth it.

Have some patience.

Placing restrictions on yourself well within your limits will force you to only install habits that you are truly excited about.

Imagine if you just did something that you’ve been trying to get yourself to do for long time. 30 days into The Assignment Challenge, I was buzzing at the thought of The No Alcohol Challenge, because I had wanted to break free of social dependency on alcohol for such a long time, and now I knew I was going to do it!

Narrowing down is powerful.

Over-Achieving on the Macro Scale

90 days is not necessary.

Some people say 21 days is enough time to form a new habit. Some say 30. Some say 45. Some say 66.

A broken clock is still right twice a day, and no matter how much time you think a habit takes, you’ll be right some of the time, because it depends.

Screw them all, you don’t need to know the number.

90 days is about double the minimum necessary time for average habits to be installed.

This gives you the knowledge that success is only a matter of time (as long as the new behaviour is simple, see next section). When you tick off that last box, the habit will be a part of you.

This lack of doubt, coupled with being forced to prioritise and choose only you most exciting self-improvements, will bring up from within a hitherto unknown ability to simply say “No”.

I was shocked at how easy it was to turn down a beer once I started my No Alcohol Challenge.


It was all thanks to my rational faith.

Go less than 90, and you won’t be quite so sure.

If you want to go over 90, knock yourself out. If your habit is very difficult, it might take longer, which is why the next section on under-achieving on the micro scale is important.

Under-Achieving on the Micro Scale

The Minimum Viable Day is critical.

It must be genuinely easy to accomplish. Listen to B.J. Fogg, the creator of the Tiny Habits concept. If you make the “success” of the habit very low, you’re far more likely to do it, of course. And then, you’re much more likely to do a little more, and then a little more, and keep going until the change is really significant.

Combining that wisdom within the framework of a strict 90 day commitment is magical.

Day to day, you won’t feel very much more overwhelmed by 90 days than 30 days. Our emotional brains can be traced back to a very distant ancestor, certainly long before anything on earth started planning ahead by a few seconds, let alone days or weeks!

Even today, while our conscious brains are easily able to time-travel, our emotional centres are dead-focussed on the here and now.

Understand the nature of your emotions, and you can work with them.

Within the day, the threshold of success must be as low as possible, so that you keep the chain going without breaking it.

The over-achievement of the 90 days means the under-achievement of small day-to-day goals won’t matter. As long as you keep doing the MVD at the very least every day, you’ll have your new habit by the end. Your emotional wiring would have changed on a physical level, and you’ll find higher targets far easier.

For some challenges, the bar of success can’t really be lowered. Abstinence challenges, such as no smoking, fall easily into this group. It’s okay, we can get over that too by stacking your advantages.

Stack Your Advantages

(Warning: Humility required)

In the past, I wanted to know I could succeed on my own, even with a bunch of handicaps holding me back.

This isn’t wise, but you see it everywhere.

“I could do it blindfolded!”

“I didn’t study at all for that exam.”

I still see the logic, I suppose. A feat seems more impressive with a handicap. But do you know how much the examination results care how much you studied?

……… cough ………

About that much.

And the same goes for the entire world and everything in it.

Running a marathon with steel-capped boots doesn’t get you an even shinier gold medal… it just makes it far less likely that you’ll get the medal as the guy who’s wearing shoes that give him an advantage over you.

Your new client is your new client, regardless of whether you did no marketing outreach and bumped into her at the supermarket, or if you committed to cold-called 30 businesses a day for a week, and found her that way. The only difference between the two is the first one is unlikely to happen, and the second is almost certain.

Results don’t care how they’re achieved. Results are results.

Your own biology is no different.

The new neural pathways that need to form for your new behaviour to stick are going to myelinate themselves if you keep doing the new behaviour… and that’s it.

They’re not going to give you “man points” for refusing to reach out for help, or not bothering to do your research, or adding some other pointless handicap.

Another friend of mine recently did a 90 Day Challenge of her own. I offered to be her accountability buddy, and check in with her every day to make sure she stuck to it, and she refused. She said she wanted to see if she could do it herself.

I was baffled, until I remembered thinking that way myself.

It’s a tempting trap to fall into.

She missed a few days in her challenge, due to being busy and forgetting. But she kept going until the end anyway, and because 90 days is such an over-achievement, these blank days were more or less absorbed by the rest and would not have taken away from the good that was done in her mind.

However, it’s nice to make your first attempt a flat-out success. Not necessary, perhaps, but it’s a nice start to the track record.

You’re just a human. Results are all that matter. The world doesn’t give you extra points for effort.

Instead of listening to your pride telling you to do it on your own or without other advantages, listen to the part of you that just gets excited about the results.

This is the same part of you tempts you to cheat in a competition.

And it’s also the part of you that pushes you to train hard for a competition, to give yourself every advantage you can get within the limits of the rules.

Luckily, when it comes to the internal competition of developing yourself, there are no rules.

So stack your advantages!

  • Get an accountability buddy. Extra points if he/she is doing the challenge with you.
  • Post your challenge on Facebook.
  • Set up a forfeit (publicly announced), for example, if you fail you have to:
    • Hand over £XXX to your accountability buddy if you fail
    • Hand over £XXX to a charity that you DESPISE
    • Shave your head
    • Eat something you hate (for me, bananas)
  • Set up daily reminders on your phone.
  • Set up even more reminders, using IFTTT, to send you email to nag you.
  • Identify all the “trigger points” that might send you off the wagon, and brainstorm ways to mitigate them.
    • e.g. If you’re trying to quit smoking, and you love a pint and a smoke in the beer garden, be aware that the next time you go out with your mates, you’ll feel a metric ton of temptation. YOU MUST PREPARE FOR THIS, in whatever creative and compelling ways you can think of.
  • Set up REWARDS for each time you succeed. To be most effective, these should be immediately after the good behaviour. Timing is more important than the intensity of the reward. (See from 15:30 in this video)
    • I repeat, they should be immediate. There’s a reason why hangovers don’t stop us drinking – We feel them the next day. Do you think you would drink if you felt a hangover as soon as you took your first sip? Timing matters.
  • Do your own reading on human behaviour and habit change. Learn about the biological system that you’re dealing with, and work the system.


If You Start Your Own 90 Day Challenge, Tell Me About It!

The 90 Day Challenge works for me.

If it works for you, I can’t wait to hear about it!

Let me know in the comments, or shoot me an email.