5 Lessons Learned from a 5-Day Fast


[Legal Disclaimer: Please be sure to consult your doctor before attempting to do a fast like this. Every person is unique, and this may not be safe for you depending on your health or other factors.]

On March 1st of 2019, I decided to attempt a 5-day water-only fast.  

This wasn’t completely new territory for me. I had tried to do it once back in 2015 after listening to a Tim Ferriss podcast episode extolling the merits of longer-form fasts of this kind. But by the end of day 2 (which is generally known to be the toughest day to get through), I’d succumbed to my hunger and headaches and broken the fast.  

So why was I attempting this again? 

Myriad health benefits have been linked to fasting, some of which include: weight loss, fat loss, increased focus and energy (after your body has kicked over into ketosis on day 3 or so), the resetting of your biome, anti-aging/longevity, and the destruction of any precancerous cells that might be in your body.

But, being perfectly honest, this wasn’t something I chose to embark on for health reasons. For me it was much simpler than that: I chose to try a 5-day water-only fast because I wanted to see if I could do it. I was curious to find out if I had the mental toughness, will power, and grit to see it through. 

The punch line? On the morning of Wednesday, March 6th, I successfully completed my fast (and documented the whole thing in a series of daily Instagram stories that you can check out in my IG story highlights if you’re curious to witness it). 

I have no idea how much weight I lost (I don’t have a scale on-hand, and that wasn’t my goal in doing the fast), but I felt utterly triumphant from a mental perspective to have successfully finished it. I was proud of myself for being able to overcome my body’s yearnings and stick with the goal I’d committed to.  

But beyond that, I also learned some valuable life lessons from completing this challenge. And I’ve distilled them down to the following 5 that I felt were worth sharing:

1.      Preparation is (largely) overrated.

My decision to attempt a 5-day fast was pretty spur-of-the-moment…so much so that I even had breakfast on the morning of Day 1 before deciding to give it a shot. 

I had a couple of friends who had recently attempted similar fasts, and so the concept had been primed for me. But beyond that, I found myself drawn to the idea of starting a fast on the first of the month, and – if this was something I wanted to do quarterly going forward (to perpetuate the health benefits referenced above) – doing it at the beginning of March would set me up well to repeat it in June, September, and December.

So I opened up the Zero app (which I highly recommend using to track your fasts – even if you just do intermittent fasting), and officially started the timer.

I’ve had a slew of people ask me how I prepared for this fast or if I was supplementing it with broth, ketones, a lemon/cayenne concoction, etc. And the answer is no. 

I didn’t prepare. At all. And I didn’t supplement my fast at all either. I only drank water for that 120-hour period. 

The lesson? 

You don’t need to “prep” for as many things as you think.

Now, I’m not saying this applies to everything. Some objectives, like running a marathon, necessitate training of some kind before taking them on. But I personally believe that we can sometimes fall into the trap of over-preparing for things that don’t necessarily warrant all that much preparation. And that tendency of ours to focus on the upfront preparation can become an excuse that holds us back.

2.     Don’t underestimate the importance of your mindset. 

Our mindset, vision, focus, and will power are incredible devices that we can leverage to accomplish nearly anything that we set out to do. 

So much of completing a challenge is mental - which means you need to feed your focus

What did that look like for me in the context of my fast? Well, I didn’t fixate on food or what I wanted. Instead, I focused on being productive, staying busy, and drinking water. Whenever my thoughts shifted to how hungry I was, I just gently redirected them and turned my attention to other things. (A part of me wonders if my daily meditation practice helped me to hone this skill, but that’s a bit off-topic). 

My experience demonstrated to me that having the right mindset is key to accomplishing the goals that we set out for ourselves. 

I had the requisite mindset – the determination – that I was going to complete this challenge. I knew and envisioned how day 2 would be the toughest point in my fast (based on what I had read and heard but also personally experienced on my previous fast attempt). More than anything else, I envisioned my success.  

Amazing human feats have been attributed to will power. Our mind is often stronger than we give it credit for. And our will power can act like a muscle that grows stronger the more that we flex it. 

3.     Social accountability is a hugely powerful tool.

Although I knew in theory that having some social accountability in place could be helpful when looking to stay committed to something, I didn’t realize exactly how helpful it could be. I’d even go so far as to say that I don’t believe I would’ve completed my fast if I hadn’t proactively built-in social accountability for myself.

I chose to post ~2 minute video updates to my Instagram and Facebook stories each day (and announced upfront that I’d be doing so) in order to share my experience and let people know what I was doing so they could follow along on my journey if they wanted to. This approach, apart from appeasing my concerned family that I was still alive, engaged my social network as participants in my fast – giving them the opportunity to watch, listen, learn, and ask me questions throughout the process.

And, as I already said, I truthfully don’t know that I would’ve made it through the full 120 hours if I hadn’t had literally hundreds of people watching my updates each day, sending me messages of encouragement, and holding me accountable. 

When it’s just you, it’s much harder to hold firm to the goals that you’ve set out to accomplish. It’s easier to allow excuses to arise and cave to your cravings. But if you can leverage social support and enlist others to root for you, your commitment grows more steadfast.

A support network is a powerful thing. 

4.     Dream big & don’t underestimate what’s possible.

What sometimes (or even often) seems impossible can, in fact, be possible.

In 1954, Roger Bannister did something that people had previously thought to be completely inconceivable: he ran a mile in under 4 minutes. Runners had been trying to break through that barrier for decades and never been able to accomplish it.  

Yet, what happened afterwards was perhaps even more incredible.  

Within the following year, multiple runners ran a mile in less than 4 minutes. And in the ensuing decades, over a thousand runners have achieved the same feat.  

What had changed? We hadn’t biologically evolved to become faster in such a short amount of time. No, the shift was psychological as opposed to physical in nature: Bannister’s achievement shifted our mental model of what was within the realm of possibility. It became possible once others saw that it was possible. 

This was the case for me as well. I had seen at least one of my friends successfully complete a 5-day water-only fast in the weeks prior to me attempting my own. And if he could do it, I knew that I was probably capable of doing it too.  

So if you want to set out to accomplish something that seems particularly daunting, I’d recommend that you first try to find examples of others like you who have done it before.  

Stay open to possibility. Dream big, but – more importantly – play big. Go for things that others might perceive to be impossible. Then show them what actually is possible. Be like Bannister – and think of the impact you could make or who you could inspire by doing so.

5.     It’s often worth it to trade-off short-term pain for long-term gain.

Many of the greatest human accomplishments have arisen from long-term commitments and pursuits. (And I’m certainly not suggesting that my fast falls remotely in that bucket). But my point is this:

In this age of instant gratification and ever-shortening attention spans (are you still even reading this right now?), it’s become less and less the norm for us to be willing to sustain pain, discomfort, etc. in the name of achieving longer-term gains. But doing so can still be beneficial or even necessary.

 (I’d recommend that you check out Angela Duckworth’s book, Grit, if you’d like to learn more about how the ability of some to go after bigger goals that require more time, effort, and investment can ultimately set them apart).

When we make short-term sacrifices or are willing to withstand discomfort in the name of a longer term gain, it often makes the ultimate accomplishment all the more satisfying. And investing the time and energy to go after longer-term goals like this can even have the power to shift your identity. Because, as you gradually work toward your goal, you come to view yourself as stronger, more mentally tough, and more capable.


Once my fast had ended, I walked away with one overarching realization, and it’s perfectly captured by a quote from the film American Beauty:  

“It’s a great thing when you realize you still have the ability to surprise yourself.”

The act of doing something that you weren’t sure you could do carries incredible power. It sparks your spirit. It lights you up and makes you feel more alive than you did before.

With that in mind, I’d like to offer up the following challenge to you: 

Explore how you might be able do something in your own life to surprise yourself – maybe not by taking on a 5-day fast like me, but perhaps by trying out a sport you never thought you could do, or teaching yourself a new skill, or testing your limits or resolve in some novel way. 

And if you accept this challenge, I’d love to hear how it goes. So please drop it in a comment to this post or shoot me a note at kim@whenitsknotforever.com.

Let’s see how it can impact our lives when we have the courage to get out there and surprise ourselves a little more regularly.