Applying the 40 Percent Rule to Running

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I recently read the new book ‘Can’t Hurt Me’ by David Goggins. Goggins is often branded ‘the hardest man alive’ having been a Navy SEAL, completing over 50 ultra races (runs, triathlons, cycling) and beating the world record for the most pull-ups done in 24 hours.

What makes his story even more remarkable is he used to be an overweight 297-pound pest exterminator with no motivation, no passion and no future. One day he said enough is enough and vowed to change everything.

In the book, Goggins explains something he invented when he began competing in ultra-distance events called ‘the 40 percent rule’.

Goggins completing an ultra-marathon.

What is the 40 percent rule?

The rule refers to how our mind tells us we’re done, mentally or physically, when in reality we’re only 40% done.

Goggins explains that the mind is built to trick us and protect us from danger. When we experience something difficult or too challenging, it goes into fight or flight and we feel like quitting and throwing in the towel.

Sound familiar? This is not an uncommon experience in life. Think of a time when you feel like you’ve given all you can give and have, sadly, given up. It could have been studying for a test, preparing for a job interview, practising a new musical piece, or even something physical like renovating a house. We feel mentally and physically drained like we have nothing more to give, so we give up and quit.

The 40 percent rule argues that when we’re in this beat downstate, we still have a remaining 60% left in the tank. This might sound crazy to some people.

A first-hand account of the 40% rule in action

After seeing David Goggins complete a 24-hour team relay run as a one-man team, Jesse Itzler invited the SEAL to live with him for 31 days to teach him the techniques needed for mental toughness. After the experience, Itzler wrote a book ‘Living with a Seal: 31 days Training with the Toughest Man on the Planet’.

In the book, Itzler describes the rule as follows: “He would say that when your mind is telling you you’re done, you’re really only 40 percent done. And he had a motto: If it doesn’t suck we don’t do it. And that was his way of forcing us to get uncomfortable to figure out what our baseline was and what our comfort level was and just turning it upside-down.”

My personal experience with the 40 percent rule and running

I was sceptical with the 40 percent rule, to begin with. How could something that sounds so simple work so well to drive you onwards in a difficult situation? During a long run I embarked on, in my early weeks of training, I had a chance to try the rule out.

I got to mile 8 and was running at a decent 7:30 minute a mile pace, and suddenly hit a wall. Each step was agony, I was grasping the air for oxygen, sweating a waterfall and had lost the will to continue. I was close to walking home and throwing in the towel, but I remembered the 40 percent rule.

Despite my mind and my body telling me no, I pushed through the pain in an effort to reach my other 60%. It was extremely difficult, and I was in pain for 5 minutes. After 5 minutes had passed, something strange happened. The pain had disappeared entirely, and I suddenly felt rejuvenated and driven to run. I even upped the pace a little and started to enjoy myself. When the next 12 miles were complete I had a huge smile on my face.

I was so close to quitting and walking home. Little did I know I had another 60% of effort left inside me, waiting to be unlocked with a little grit and determination.

This experience made me realise the 40 percent rule is true. We often quit as soon as we experience an obstacle or pain, denying ourselves the chance to push through the discomfort and suffering for the glorious achievement on the other side.

When we think we’re done, we actually have more to give…

How can you apply the 40 percent rule to your running?

Failure will never overtake me if my determination to succeed is strong enough.‘ Og Mandino

We all have our own running goals. Some want to run a 5K without stopping. Some desire to finish a half-marathon in under 1 hour 40 minute. Others aspire to compete in ultra-distance events.

Whatever the goal, there will be some effort and discipline required to achieve it. Any worthwhile, meaningful goal will mean you have to sacrifice something. It won’t be comfortable, and you may feel like quitting.

In those moments of running where your brain is telling you that it’s time to bail, remember the 40 percent rule. You’re only 40 percent done and have another 60 percent of effort left to give. It.

Start by giving an extra 5 percent. Maybe you run a quarter of a mile further or faster, even though you have zero motivation to do so. Once you have done this, you’ll have more confidence in yourself and will feel driven to give another 5 percent. And another, and another, and another.

Before you know it, you have run further and faster than you thought possible and you will beam with pride.


Note: The rule is designed to push you beyond your supposed limits, not to seriously injure yourself…

Please understand Goggins did not invent this rule for you to kill yourself and take it to extreme lengths. If you really are in huge amounts of physical pain (a really tight chest, ridiculously high heart rate, broken bones etc) then it’s a good idea to stop and recover.

The 40 percent rule is amazing for driving you to put out more than you thought physically and mentally possible. It’s not there to put you in any real danger. If you are in true pain or know you have done damage to yourself, consult a medical professional immediately.


Thank you for reading this article. If it has been useful please share it will fellow runners and see what they think.

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