In the sport of distance running, we are used to embracing the idea of mental toughness. Whether it’s embraced through your standard Steve Prefontaine quote about guts and glory, or from the recent front running, make everyone suffer tactics of marathoner Shalane Flanagan, runners take pride in their ability to hurt. We spend countless hours trying to sharpen our own mental fortitude, but ask any runner from the elite to the weekend warrior and having mental strength to either push through the last miles of the marathon or even simply to get out the door for another early morning run, is on the top of their list. The question is, what is this mysterious toughness and can we train it.

To tackle this question, we need to delve into the world of cognitive psychology and use the concepts of will power and self-control to give us clues on how the mind works during difficult situations.

According to the most recent models of fatigue, when we race, the pain we feel is an emotional response that is intended to keep us from venturing outside of the safe walls of homeostasis and causing harm to ourselves. Whether we speed up or slow down during a race is simply a decision. Based on our prior experiences, our expectations, the metabolic feedback that our brain is receiving, and a dash of motivation thrown in, our brain essentially tells us whether we should make the decision to slow down and give in to the fatigue or to try just a little harder to keep going.

Willpower, Self-Control, and Fatigue

Will power and self-control refer to how well we can override or resist desires. For example, when the alarm goes off at 6am for your morning run before work, it can be incredibly tempting to hit snooze and get another hour of sleep. If you resist and instead get up and go about your day, you used a small bit of willpower to overcome the desire to sleep. The same could be said for forgoing that piece of chocolate that you really want before dinner.

The interesting thing is that willpower seems to be a finite resource. We seem to have a pool of “willpower energy” to draw upon each day. As that pool of energy is used up, our ability to resist and use self-control diminishes. For example, research has shown that resisting the same temptation, like chocolate or another sweet, early in the day is easier than resisting later in the day. Similarly, there have been numerous studies to show that if we are made to exert self-control on one task, then we are more likely to give in on a
subsequent task.

We can imagine having a bucket filled with willpower. Every time we have to use self-control to resist some temptation, we dip into that bucket. The more we stress over that temptation or the longer we resist it, the more we delve into the pool. As we go throughout the day, because our bucket is draining, our ability to resist temptation decreases. Similar to how as we run low on fuel running, we develop fatigue, the same happens with self-control. Just like we might drink a recovery drink after our fatiguing long run, our willpower bucket needs to be refilled.

Before delving into refilling the bucket, let’s look at other items that may drain our bucket. Going beyond simply resisting temptation, scientists break willpower down into four different domains: controlling thoughts, controlling feelings, impulse control, and task performance.  Each of these domains represents a different way to use willpower to resist temptations.

But it goes beyond simply just resisting temptations. It turns out that decision making uses willpower too.  Scientists refer to it as decision making fatigue. The more decisions we make, or the more trying,  worrisome, or elaborate a decision is, the more it delves into our willpower reserve. Interestingly what happens during decision fatigue is that not only will our self-control be impaired, but also our decision making will suffer. We
will be more likely to avoid making a decision, pick the “default option” and not think it through, or give in to our natural bias. Basically, we become bad decision makers.

A great example and somewhat scary implication is seen in courts where judges make parole or sentencing decisions. Several different studies have now shown that the judges likelihood to sentence is significantly higher before lunch, so at the end of several decisions made in a row, versus when the judge has just returned from lunch. It’s scary to
think about that this happens, but it illustrates the point of decision making fatigue.

Additionally, and not surprisingly, physical fatigue impairs willpower. Some research has shown that if we restrict peoples sleep to 6 hours or less a night then they will have a decrease in self-control.

So what we are left with is a situation where decision making and using willpower both effect self control, which in turns decreases initiative. So if we deplete our resources we not only won’t resist temptations as well or for as long, but we will also show a lack of initiative to start tasks. It’s a brutal cycle impacting both our drive and control.

Now that we’ve established the effects and possible impact of willpower depletion and decision making fatigue, why am I talking about this in a running blog?

Running Strong

As mentioned in the introduction, running and racing is all about making decisions. Whether conscious or subconscious decisions, our brains and bodies make choices based on not only the physiological changed going on when we are running, but also our emotional states surrounding it. We’ve already seen research that shows that if we perform a mentally taxing task before a maximum exercise test, we will perform worst as mental fatigue effects our physical performance. But we can go a step further and look at fatigue from a decision making perspective. Let’s try to connect the dots.

Self-control is all about overriding responses. It’s about shutting down those desires or temptations that crop up as we go through life. Maximizing race performance is little more than overriding the brain’s desire to slow down and maintain homeostasis. Those sensations of fatigue are thought to be your brain trying to force you to slow down voluntarily. As the feeling of pain increases, it’s your brain knocking louder on your conscious brain to listen. If it doesn’t, it’ll eventually shut you down anyways, but hopefully much later into the race. So in a sense, when we race, we are utilizing willpower and self control.

But that’s not all. As willpower is depleted, researchers have found that everything intensifies. Regardless of if they are positive or negative, emotions are enhanced so that we experience them to a much higher degree. Something that would normally only make you mildly upset now sends you into a rage. Along with this, desires are similarly intensified. We lose impulse control and have stronger desires when we are in a depleted state.

If fatigue is simply an emotion, then as willpower is drained, the feeling of fatigue is amplified. So we are not only dealing with an increased sensation of pain as we venture further and further away from homeostasis, but we are hit with an increase feeling of that pain because our willpower is gradually depleted. At the same time, our desires increase so that the typical thoughts of dropping out of a race, slowing down, or cutting a workout short are increased.

With this entire charade going on, it’s a wonder that we resist our bodies as well as we do! But it’s not all bad news, researchers have found that how the decision making process takes place matters.  According to Dorris and Power’s research, when you make a decision more automatic, it shifts from a conscious process to one called “nonconscious self-regulation. And what they’ve found is that when decisions shift to this type of regulation, less depletion occurs.

Some sugar and sleep?

There is one phenomenon that seems to temporarily restore willpower and it’s sugar, or more precise, glucose. Taking a hit of glucose has consistently been shown to increase willpower and subsequent self control. There’s even been research that shows that a drop in blood glucose to the brain might be one of the “causes” of willpower depletion.

The implication of the glucose hypothesis can be seen in the world of running. Perhaps it’s not only your muscles that need the fuel during that marathon, but also your brain for willpower restoration. While this is only speculation maybe this idea partially explains why taking a hit of glucose even near the end of a marathon when the glucose doesn’t have time to get to your muscles, still helps performance. Or why some athletes and some studies show glucose supplementation during a race that lasts an hour, which is far too short to come near glycogen depletion, still helps improve performance. Maybe it’s simply giving your brain a boost in willpower, just for a moment, so that you can resist that temptation to slow down and avoid the pain for just a bit longer. Those studies on judges decision-making following multiple decisions we talked about earlier, also found that if a judge took a snack break, and got some glucose, the likelihood of having a favorable sentence went up dramatically.

Sugar isn’t the only thing that seems to aid in restoration of willpower. Not surprisingly our good friend sleep helps too. Researchers found that in subjects who had 6hours or less of sleep per night, they saw a decrease in willpower, which tied to a decrease in brain activation in areas that are associated with willpower.

The point is that external factors can increase willpower and not surprisingly nutrition and recovery top the list. So we’re left with the fact that recovery and nutrition aren’t solely for repair of those muscles pre-race, but also for your brain and your mind. Before finishing off with what we do about all of this, I think there are some interesting implications of willpower, self-control, and decision making in regards to running.


  • If we are drained of willpower going in, we don’t have a full reserve to battle with and will give in earlier.
  • The earlier we have to use willpower in a race, the faster it will likely be drained. So if you’re in a panic 1 lap into a 5k, you’re in trouble.
  • As we use more willpower and become more depleted, emotions and desires amplify. So that feeling of pain is felt more, that desire to drop out of the race or slow down increases.
  • Racing is essentially impulse resistance. Practice it and we can dampen down the response.
  • Sleep is not only a physical recovery tool, but it’s an emotional and willpower recovery tool too.
  • Glucose may help via willpower and self control mechanisms.
  • Work on making decisions automatic to delay draining of self-control.
  • Research shows that routinely practicing activities that work on persistence in the face of fatigue or obstacles can lead to automatization of the process. This means that if we can frame races and training correctly, we can ingrain this “mental toughness” ability.

So what?

Now that we’ve delved into all of this fascinating research on self-control, willpower, and decision making, what can we do beyond recognize it’s importance and try to keep our willpower reserve filled?

  1.  Prioritize

Don’t waste decisions or stressing over decisions on inconsequential problems. Far too often we stress over small decisions with little or no payoff, and just end up causing decision making fatigue. Don’t stress over what to eat for breakfast or what color shorts to

  1. Make Important Decisions Automatic

I always tell the story of how when I was running 110-120mpw in college, it wasn’t a decision if I was going to run or not. There were no decisions. It became a part of my life where at 7:05am every morning I’d run 9 miles without fail. And every evening I’d run another 7-9mi. It’s cliché to say, but it was so ingrained that it was like brushing my teeth. Just like teeth brushing, make the key decisions in your life and in running, automatic. Research shows that automatic decisions drain less of your willpower, so take advantage of it.

  1. Plan

If you know you have a big race, test, challenge, or event coming up, plan it out so that you aren’t depleting your willpower going into it. Look at it like training and simply taper off things that suck your willpower going into the event.

  1. Train

The mind can be conditioned. How we respond to challenges and tests of self-control become ingrained into us. I always like to point out that, you can change how your brain activates and that can be a good thing or a bad thing. You can actually increase your capacity to deal with depletion of willpower. You can train to have a bigger reserve or take smaller scoops out of that reserve with each challenge.

Some research has shown that doing simple willpower tasks can increase this ability. For example, something as simple as holding ones breathe to resist that feeling of stress brought upon by dwindling oxygen is one example. Another is by exerting self control, and being successful at it, in resisting a bit of chocolate that you have on your desk or carry around.

  1. Framing

Along those lines, how you process success, failure, and challenges shapes how much willpower is depleted and used. For example, researchers found that the harder you are on yourself when you have a willpower failure (i.e. Scolding yourself for eating that piece of cake), the more likely you are to have that same failure again. Similarly, if we frame the race or training correctly, we can make conscious decisions automatic.

  1. Emotional Response

Whether it’s life or running, the emotion is simply the feedback. We experience and feel it, but it doesn’t mean we have to respond in a certain way. If we feel a lot of pain during a race, it doesn’t mean that we must immediately slow down. We can build this capacity to resist it. Similarly, in life we can build that capacity to respond to emotions in a similar
way. It’s up to you.

In a study by Muraven (1998) tested how long a person could squeeze a handgrip after having people control their emotions in response to a sad video clip versus people who let their emotions run free. Not surprisingly, people who didn’t try to regulate their emotions, could last longer on the handgrip exercise. Showing that framing and knowing when and how to respond emotionally matters.

  1. When and Where of Self Control

The key to having high self-control and being mentally strong isn’t some magical strength. Instead, it is knowing when and where to exert self-control and making sure that for truly difficult tasks you tapered and fully stocked with willpower before delving in. If you’re spending your pre-race day fretting over having the exact right food, having the exact amount of sleep, fretting over decisions on what to wear, when to be at the race, and so forth, you’re missing the boat. Being high strung and resisting everything only gets in the way when a critical decision is coming.

The bottom line is that willpower, self-control, and decision making are a part of our everyday lives. We can train to deal with all of them better and use tips and tricks to minimize our depletion of the former. In the world of exercise though, I think there are some very interesting parallels of willpower/ego depletion and the latest theories of fatigue. While much needs to be researched, there are some interesting implications for how we might need to shift our focus to not only being tough, but at looking at how we approach being tough to maximize our performance. It might be about not only resisting fatigue, but making sure we have a full willpower tank going into the race.


Investigating the effects of ego depletion on physical exercise routines of athletes Derek C. Dorris a, *, David A. Power a, Emily Kenefick b

The Role of Glucose in Self-Control: Another Look at the Evidence and an Alternative Conceptualization Christopher J. Beedie and Andrew M. Lane

Ego Depletion and the Strength Model of Self-Control: A Meta-Analysis

Attentional focus in endurance activity: new paradigms and future directions Noel Brick, Tadhg MacIntyre* and Mark Campbell

Get My New Guide on: The Science of Creating Workouts


    1. el sombrero on May 8, 2014 at 6:57 pm

      is there a way to quantitatively measure willpower? Like get a number that says on average Mo Farah's will power is 54 and Rupps is 52 or something? So many factors it would be hard to do. Maybe some task that's just willpower like resisting food in a room for a period of time I dunno.

      cool article

    2. Stan ( on May 8, 2014 at 7:52 pm

      Thanks for this, Steve. My problem has always been running my training runs at the pace I need. For example, during my last HM training cycle, I managed a 42:00 10km during training (feeling every bit of it). Two weeks later, I ran a 38:29 10k (fairly easily) in a time trial race despite the fact that I logged the same amount of miles in those weeks (60 miles) and performed virtually similar workouts. It has always been this way for me. I can push off the pain and fatique in a "real" race even during the middle of a training program but can't achieve the same result in a non-race.

      Any tips on how to stay more motivated during training? Does this happen to a lot of people?

      Thansk and keep up the great blogging!

    3. na yiu on May 15, 2014 at 10:11 am

      this could be a measure of power of human endurance and the will, the will is a very important thing, I adore his perseverance for the purpose set out, thank you for sharing it. friv 10

    4. Andy Renfree on May 15, 2014 at 3:21 pm

      I wonder is this is part of the benefit of having a pacemaker set the early speed in record attempts? They will undoubtedly have some role in reducing wind resistance, but perhaps they also assist the followers by reducing the need to make decisions about the speed at which they are running.

    Leave a Reply