Once upon a time, a 100 Day Experiment saved my life.

I know that sounds dramatic–but it’s absolutely true.

In 2013, I took a ten-day trip to New York City with my daughter. I came home in so much pain that I couldn’t put my own pants on. My husband literally had to pull my pants up for me. For months.

Around that time, I started snoring at night so loud that my poor husband had to wear ear plugs so he could sleep. (We just celebrated our sixteenth anniversary, so our marriage did survive 2013. He is a patient man.)

He was afraid for me, because besides snoring, I also stopped breathing in my sleep.

I was sick. So sick. Everything hurt all the time. My whole body was swollen and miserable. I weighed nearly 400 pounds and I was starting to have trouble moving, to the point that I was truly worried about my mobility. I was so tired that I could barely function.

In desperation, I decided to try exercising for 10 minutes a day for a hundred days. I don’t know where those numbers came from, but I committed myself to ten minutes of exercise every day for 100 days.

It changed my life.

I didn’t lose much weight, but I went from barely being able to walk ten minutes a day on day one to swimming 3000 meters on day 100. My pain level decreased drastically. My mood improved dramatically. I didn’t feel sick anymore.

And I was in a position to start to make decisions about my health moving forward.

I had a sleep study and was diagnosed with Sleep Apnea.

I went on a CPAP, which instantly corrected my exhaustion.

I eventually lost 120 pounds and didn’t need a CPAP anymore. The pain stopped.

It’s been six years and I’m still working on myself. But it started with that 100 Day Experiment.

Since then, I’ve used the 100 Day Experiment in lots of ways.

Including helping me get back on track when I lost my way with writing. Writing for 10 minutes a day for 100 days turned into a blog. Which turned into a series about writing novels. Which turned into Ninja Writers. Which turned into . . . everything.

Anytime I start to feel lost or like I’m struggling with anything, I come up with some small thing — some ten minute goal — and I challenge myself to do it for 100 days.

I think there’s a kind of magic in 100 days.

It’s long enough to internalize a new behavior and make it your new habit.

I know, I know–that’s supposed to happen in 21 days. Every where we turn, someone’s trying to promise us that we can make these super fast, super amazing changes in our lives.

It doesn’t work for me. After 21 days, it’s still too easy to go back to my old habits. After 100 days, I’m not doing it just because I’m supposed to anymore. I’m doing it because it’s just what I do.

It’s a long enough time to let me see real results.

In 100 days, I can write most of a book.

Or dig out of even a deeply disorganized house.

Or, like I showed you, put myself on a path toward feeling better.

It’s also short enough not to trigger the panic of doing something new FOREVER.

There are plenty of things that I don’t worry about doing forever.

I don’t panic at the idea of having to read books until I die or never being able to stop brushing my teeth or going to the grocery store.

But sometimes, when I think about doing something new, it triggers anxiety about having to do it forever. And that anxiety will stop me from ever starting. Even if it’s something that feels good.

Turns out that 100 days is long enough for something to stop being what you have to do, and start being just what you do. And if it’s not–well, it’s a good thing there’s another 100 days coming up right behind the first, right?

I love the idea of a Slow Down Revolution. Let’s just step away from the people screaming at us that we need to do everything instantly.

The 100 Day Experiment could be its lynchpin.

Instead of trying to find the shortest route to a new habit, take it slow. Make small habits that really do stick and build into big things, instead of constantly trying to beat yourself into change three weeks at a time.

Here’s how to set up a 100 Day Experiment of your own.

Choose a habit.

Don’t get overly ambitious or complicated here.Think of something simple, that will have a big impact.

It can be something that feels BIG and difficult to do (trust me when I say that in the beginning, the idea of exercising for even 10 minutes made me want to cry) — but it should also be simple. That way there’s less wiggle room.

Make a commitment to do that thing for 100 days.

Write it down. Tell someone. Tell everyone. Get a calendar and some gold stars and give yourself one for each day that you follow through. I like to use my FRED for this.

When it gets hard, remind yourself that it’s only 100 days. Just focus on doing what you’ve promised yourself you will do today. Put your effort into just making sure that today isn’t the day you quit.

Remember your small habit is the start, not the end.

In other words, ten minutes isn’t a cut off. It’s a minimum. You get full credit if you meet that minimum goal, but the hope is that once you get started you’ll do more.

Be open to that expansion, but don’t beat yourself up on the days when ten minutes is all you have to give. Your small goal is your real goal.

Keep a journal.

This is optional, but I find it really helpful.

Get a notebook and jot down a few lines everyday. You don’t have to dive deep into your feelings, unless you want to. I really think a log of what you did to meet your experiment criteria for the day makes a big difference.

Record your little victories. Pay attention to how doing your thing is affecting your life.

Here’s my secret weapon for sticking with whatever your thing is.

Shaunta Grimes is a writer and teacher. She is an out-of-place Nevadan living in Northwestern PA with her husband, three superstar kids, two dementia patients, a good friend, Alfred the cat, and a yellow rescue dog named Maybelline Scout. She’s on Twitter and Instagram and is the author of Viral Nation and Rebel Nation, and The Astonishing Maybe. She is the original Ninja Writer.