Hey guys,

Today I’m going to break form somewhat and deliver what is essentially a book report.   

I don’t usually go into detail when discussing books here, but Endure by Alex Hutchinson had so many valuable insights for endurance athletes I felt compelled to write about it – and capture some of my notes for my own future reference.

This book is essential reading for any runner who:

– wants to know the role of willpower in running, and why running feels harder on some days when all the physical evidence suggests otherwise

– wants to better understand RPE (Rate of Perceived Exertion), and how the brain may be limiting your performance to protect you

– want to know why distance runners have higher pain tolerance (and how to potentially develop yours)

– want a great explainer to the physical limits of our body, such as VO2 max, lactic threshold, energy consumption, nutrition – the whole gamut

– are interested in the latest sports science related to endurance and performance.

Endure is also an engaging read, peppered with examples and tales from the world of endurance sports which makes it read more like a Malcolm Gladwell book than a dry science tome.

Who Is Alex Hutchinson?

Alex Hutchinson (@sweatscience on twitter) is an author, journalist, PhD physicist, and runner. If you haven’t already, check out his regular contributions to Outside magazine.

He’s a long-distance runner for the Canadian national team, mostly as a miler but also dabbling in cross-country and even a bit of mountain running.

Alex also covered the Nike Breaking2 event for Runner’s World.

In other words, he’s got the credentials in the worlds of running, science, and writing.

When Alex writes about exercise, it’s usually worth paying attention to.

What’s Endure All About?

Endure explores the latest science around the limits – both physical and psychological – of the human body in athletic pursuits, particularly running and other endurance sports.

It first explores the different limiting systems in our muscles and minds – including ideas like the Central Governor model – then breaks down the individual factors which can limit an athlete (pain, oxygen consumption, heat, etc.). 

Then it gets really interesting, as Alex details possible ways for breaking or extending some of these limits.

Rather than give a cliffnotes version of the book, I’m going to share a few of of my own key takeaways – and encourage you to pick up a copy of Endure!

Endure – Some Key Takeaways

By the way, Endure goes deep into several areas I don’t cover here, such as discussing muscular fatigue, VO2 max, dehydration, fuel – and much more. It’s also packed with great stories. My key takeaways focus mainly on the sections of the book discussing the relationship between the mind and the limits of performance.

1. The Central Governor Does Exist – But Still Baffles 

First proposed by legendary – and somewhat inflammatory – sports scientist and runner Tim Noakes, the idea that our brain sets and enforces limits on performance has been an intriguing one.

Why is it that track runners speed up on their last lap if they’ve been ‘giving it their all’ for every lap?

How is it that I can muster a sprint finish in an ultramarathon, after hours of being able to do no more than a tired shuffle?

The Central Governor theory suggests our brains have an automatic limiter in there, designed to prevent us from going too hard.

A major part of the evidence for this is that once we know the end of the performance is near, the brain relaxes that limit – allowing us to push harder.

The proposal of the existence of the Central Governor back in 1997 was controversial, as previously the accepted wisdom was that VO2 Max was the true limit of physical effort. 

But as time has gone on, wider studies have shown the ‘final spurt’ appearing again and again, though the psychological causes are still debated.

Noake’s lab in South Africa currently views the Central Governor as a ‘dimmer switch’ limiting the maximum effort possible.  What’s interesting is that new research suggests that faster athletes have less of a pronounced ‘final spurt’, suggesting they may have gradually adjusted the setting on their Central Governor so they can push harder.

2. Perceived Exertion May Be Our Most Important Metric

The traditional method of measuring your own performance is to look at physical metrics such as speed, VO2 Max, weight moved, force generated, etc.  Athletes have to stop when they reach their physical limits.

However there’s an increasing amount of interest in a “psychobiological model” – one in which non-physical factors influence our performance.

These non-physical factors can be summed up by our will to continue, which may vary depending on a host of conditions – how invested we are in the result, if we’re emotionally or mentally drained from other parts of our lives, and – importantly – our pain threshold.

In order to estimate the effects of these non-physical factors, researchers use RPE (Rate of Perceived Exertion) – which is a scale of an athlete’s sense of effort. 

It was found that doing a prescribed exercise after a mentally draining task increased the RPE, while other traditional metrics remained unchanged.

Likewise, positive self-talk and relaxed facial muscles during intense exercise have actually been shown to lower RPE.

Becoming mentally fatigued increases your sense of effort, so makes you more likely to limit your performance or throw in the towel earlier.

So – can we somehow hack our RPE?

3. Endurance Athletes Have a Higher Pain Tolerance (which may effect RPE)

Studies have shown that endurance athletes have a higher pain tolerance than non-athletes – demonstrated in experiments involving the amount of time you can hold your hand in ice water, for example.

Did they become endurance athletes because they had a high pain threshold, or did their training gradually adjust their relationship with discomfort and pain?

A further study has shown that non-athletes who have been put through a spell of high intensity training increased their pain tolerance by 41% – indicating that intense exercise adjusts your relationship with pain.

So endurance athletes develop a resistance to pain – does this affect their perception of RPE, in that they can push harder for longer and register a lower RPE?   

My Thoughts on Endure

One of the things I loved about Endure is that it brought science and balanced discussion to many aspects of distance running which are often discussed, but highly subjective.

I know from my own experiences in attempting to pace myself during ultramarathons that when I ignore the GPS and listen to my body, it tends to pick a conservative, sustainable pace. Making the leap to saying this is my Central Governor kicking in isn’t something I can provide any evidence for, but feels right. And in my travels and conversations with other ultra-runners, we all discuss the same thing – finding a pace that is sustainable, and changes depending on the conditions and distance you’re running in.  We keep coming back to RPE, that magical, subjective metric which can only be measured in your head.

Likewise on the discussion of Perceived Exertion, and non-physical forces affecting your performance. Over the past few years, I’ve had periods where my workload has left my mentally drained each day – and when I go for a run, it’s tough to muster a pace I would normally find respectable.   Attempting to rationalise this can be demoralising, until you understand that your mental state affects your RPE.

Accepting that your performance may be compromised by non-physical factors can be a relief, and potentially prevent an already bad mood from getting worse when you fail to meet your expected performance.

As for me, as I’m gearing up for a few ultras this year I’m going to intentionally train with hard workouts – both in the gym and on the trails – with the purpose being to get comfortable operating at a relatively high RPE. No concerns about pace, weight, or other metrics – just RPE.

Have your read Endure?  Share your thoughts below!

Thomas Watson

Thomas Watson

Thomas Watson is an ultra-runner, UESCA-certified running coach, and the founder of MarathonHandbook.com. His work has been featured in Runner's World, Livestrong.com, MapMyRun, and many other running publications. He likes running interesting races and good beer. More at his bio.