If you're a marathoner (or a marathoner in training), you know a unique form of determination.

Setting out to accomplish something that only 0.01% of the global population has done — running 26.2 miles, the equivalent of 105-plus laps on the inner lane of a standard running track — entails a level of persistence that may warrant at least one person in your life calling you crazy.

But is there a difference in the persistence of a first-time marathoner, aiming simply to finish, and a two-time Olympic marathon runner like Liz Yelling, looking to set a new personal best?

We want to understand the science behind your grit and tenacity. What's happening in the brain when we commit to completing an endurance race like a marathon?

We asked Dr. Beth McQuiston, a neurologist and medical director at Abbott, and she began by pointing out that every person’s brain is different. For some, their prefrontal cortex, which connects with other regions of our brains to regulate emotions, is more prominent, influencing dopamine (a chemical released in the brain that makes you feel good) when training. For others, certain areas of their cingulate gyrus, a part of the brain that impacts emotion processing, may be more active, enhancing focus, spurring tenacity and yielding positive feelings. For others, their amygdala, a roughly almond-shaped mass that impacts the experiencing of emotions, may be sparking anxiousness or nervousness to drive them.

But truly, whether you're a world-class prefrontal cortex-dominant runner or a beginner prefrontal cortex-dominant runner, you're likely experiencing the same drive.

Sure — having marathon experience may seem like it makes your upcoming race feel less daunting. But we all can relate on how it feels to set and achieve a goal, regardless of experience.

Professional vs. Beginner Runners: Mentally, Are We so Different?

We know there's a difference in the physical performance of a pro runner and new runner. But what about the mental performance?

To explore the driving force behind a new runner, we spoke with Abbott runner Claudia Guzman, who finished her first marathon in Chicago just last fall. When she decided to pursue running her first marathon, she was a true beginner.

 "I had always been interested in keeping good health and staying in shape," she said. "There are only so many workouts you can do before you really want a challenge. I wanted to prove to myself that I could do it."

For Guzman, it was picturing the finish line that kept her committed to her training, even on her hardest days. "I kept thinking about, and visualizing, myself crossing the finish line," she said. "I had that mental picture of myself accomplishing this goal, and it became about not wanting to let myself down."

In other words, her cingulate gyrus could be constantly firing, keeping Guzman focused on the positive.

Her self-motivation took her all the way to her first finish line in Chicago, and recently all the way down Boylston Street when she ran the 2023 Boston Marathon.

But what about a seasoned runner who has already proven to themselves that they can accomplish this goal — what keeps them motivated?

Olympic marathoner Yelling described a different challenge that pro runners like herself often face and beginner runners likely do not — the world is watching them.

"Especially when you're known, you're accountable for your performance. It's public, and some people are there to watch you. You don't want to let anyone down," Yelling said.

How would McQuiston explain the science behind that fear of letting others (or in Guzman’s case, yourself) down?

The amygdala may be to blame. As we mentioned above, the amygdala impacts the experiencing of emotions, and can "create mental weeds," as McQuiston describes it, causing runners to feel nervous, which can easily be caused by the fear of failure.

"When the amygdala tries to pull your emergency brake out of fear or anxiousness, you have to find a positive mental place," McQuiston said. "Things like music, connecting with others, or the support of a cheer zone can help balance out dopamine, oxytocin and endorphins for some people."

Keep that in mind for your next race. When the mental hurdle feels especially high, listen to McQuiston: Put on your favorite song, find a fellow runner or a supporter to connect with, or tap into the energy from the cheer zone.

Our brains are extremely complex, and training for and running a marathon is a lot to endure mentally, aside from just physically.  

But really, we're all in that together. Whether your next marathon is your 100^th or your first, the phenomenon of putting your mind to this goal and committing to being a marathoner is a major win.