Technically speaking, racing 12 hours at the Pettit Center was a result of years of training. In fact, every race is the culmination of years, if not decades, of training.


09-24-2019          By: Zach Bitter





It’s always interesting to me when I see someone run an incredible race. It seems like the first thing others in the sport want to know is what they did in their buildup towards that singular event. The training cycle leading up to that race is certainly important, but so is the whole process—starting from the first day they went for a run.

When reflecting on my personal experience of chasing the 100-mile World Record, I could go all the way back to middle school when I ran my first mile. However, I’ll spare you the ignorant years and fast-forward to 2019 when I began planning my race schedule.


Zach Bitter setting the 100 mile world record



Since moving to Phoenix, AZ, I have taken a slightly different approach to racing. Because I have access to so many different running environments, I like to divide my year into two halves: One half for trails and one half for more “runnable” courses. It helps reset my mind when I can move on from one environment and come back to it later. This year I had identified the San Diego 100 Mile as my trail target and the Spartathlon for my more runnable course. A wrench was thrown into the mix when Steve Durbin reached out to me to explain he was putting on an event at the Pettit Center in Milwaukee, WI, called, “Six Days in the Dome (SDD)” where runners would have options ranging from 24 hours all the way up to 6 days. With Spartathlon taking place a meager five weeks later, I was conflicted. For one, I normally prefer a sixteen-week window of time when switching my training over to a new target race, especially when it is a different environment. I remember doing the math. If I were to do SDD it would give me eight weeks including the taper. I decided to tentatively commit to doing 12 hours but was fairly certain it would end up being a tune-up for Spartathlon as opposed to an all-out effort.

Once I got into my training block, I noticed my fitness on the flat terrain was coming back much quicker than I expected. When I completed my last block of training before SDD, I was convinced I was in as good of shape as I have ever been for a record attempt at the 100-mile distance. Given the climate/weather control the Pettit Center’s 443-meter track would provide, I decided that if I felt good on the day I wouldn’t hold back.

The block of training that had me convinced was a four-week cycle of three build weeks with one de-load week. The mileage came out to 129.4, 150.1, 72.2, 150.2. The three build-up weeks included four long sessions on a dirt track four miles from my house. They ranged between 27.2 and 32.5 miles with the final two efforts back-to-back. These build-up weeks were at or slightly below goal 100-mile pace, with a few threshold runs sprinkled in when my legs felt particularly fresh. The long runs specifically were right around 6:30 per mile average pace with all of them structured to negative split.


Zach Bitter prepares for 100 mile world record



Consistency of training is a huge piece of the puzzle, but there are other tertiary activities and decisions that help keep the running manageable. One personal example of this that I identified early in my ultra-marathon running career was that I wanted to avoid lower leg injuries, overuse injuries, and muscle imbalances as much as possible. Over the course of my post-collegiate running career, I have addressed these in a variety of ways including working on strengthening my posterior chain with kettlebell swings and deadlifts, stiff ankles and hips with mobility work, and lower leg strength with proper footwear. I had lost an entire indoor and outdoor track season in college due to Achilles tendonitis. Lower leg muscles, although often easy to forget, operate the same as all others. A small increase in stimulus followed by adequate recovery will gradually make them stronger over time. My weapon of choice in this journey was low profile natural footwear. Putting anything on our feet provides protection. The more protection you use, the more you potentially allow certain areas of your feet to atrophy. Think of it like wearing a cast on your foot. If you did that to your hand, imagine how weak your grip strength would be when you took it off? Over the years, I have exposed my feet to thousands of miles in low(er) profile shoes in hopes of creating bulletproof lower legs. It is my best example of taking a previous weakness and turning it into a strength. I am confident this is a big reason why I can wear a low profile shoe like the Altra Vanish or Solstice for 100-mile races.

The race itself wasn’t too hard for me to wrap my head around. However, how it played out was. Before SDD, I had never negative split a 100-mile race. Historically, I have always planned on at least a slight pace reduction, so I would aim for the first half to be a bit faster than the second. When I came through mile 40, I did some quick math in my head and realized I would most likely come through 50 miles in about 5 hours 40 minutes. This briefly alarmed me. It was hard to shake the fact that I had never negative split a 100 miler, and with that mindset, I would be on a razor’s edge of breaking the 100-mile World Record of 11 hours 28 minutes 03 seconds. I recall a thought crossing my mind around midway that I should just relax and take what I get on the day and focus on Spartathlon. It was a moment of weakness, no doubt; especially in hindsight. I firmly believe that if you did the work in training, the biggest variable between having a good or great day is how many times can you push through self-doubt.

Fortunately for me, after having that moment of weakness, I glanced over at the screen which displayed each lap and noticed my pace was still within the ranges I had set before I started. I reflected on how much time and energy I spent preparing for this race and told myself to remain focused. One trick I like to use is mentally minimizing the task at hand. Yes, 12 hours is long, but when compared to the hundreds of hours, days, weeks, months spent preparing, it is relatively small. I like to tell myself that even if I have hours of running left, I’m in the final percent of the whole process.

When I went through 100 kilometers, I saw my split of 7 hours 03 minutes. This was motivating to me because it inched me closer to a point in the race where I could wrap my head around what was left. It was also five minutes slower than what I split at Desert Solstice in 2015 when I broke the American 100 Mile Record but fell short of my A goal of the World Record. That day I really struggled in the final fifth of the race. I gave back much more time than I should have from miles 80-100. It was at this point I realized that I felt great and that perhaps paced things right. Perhaps I’ll have a chance to get back what may have been a missed opportunity in 2015.

When I started closing in on mile 70, I got into a much different headspace than I had been in all day. At this point, all I had left was a single long run. No more did I need to think about running 100 miles that day. I could now just do what I had been doing for weeks leading into the race.

This new mindset helped pass the next 10 miles quickly. It felt somewhat strange since historically I have always felt like the final stages of 100 milers felt like every minute was two. I didn’t give this too much thought other than some motivation that things were going well. When I hit mile 80, I had another shift in mindset. The mile 80-100 stretch I mentioned above was now my driving motivation. I was in a great spot to finish under the 100 World Record. It almost felt like I was able to go back in time and redeem what I left on the table at Desert Solstice 2015. I was as motivated as ever to make sure this time would be different.



Zach Bitter reflects on setting world record



When the screen reflected single digit miles remaining, I thought about the way I had structured my long runs for this race. I had negative split all of them. With such a short distance remaining, I put myself back in that atmosphere I created in training. When I was told I was on pace to run 11 hours 20 minutes and some change rather than holding on for dear life, I thought no—I’m going to push myself to go under by another minute.

It was one of the days where I felt like I could push back the doubt just a few more times than normal. Why that happens sometimes and not others is anyone’s guess, but I can’t help a nearly six-year journey from the first time I ran a 12-hour timed event to SDD gave me plenty of opportunities to learn from my mistakes, better personalize my own training, and find the right path to a long-term goal.

I crossed 100 miles in 11 hours 19 minutes 13 seconds. I had officially negative split 100 miles and felt stronger the second half than the first. For a moment I thought that I was daydreaming and was still at mile 50 staring at the screen showing 5 hours 40 minutes with no chance of replicating, much less speeding up.

The uniqueness of this event is that if I had a great day there would be a solid amount of time on the clock when I hit 100 miles; meaning I could keep going and see how far I could make it in 12 hours. Although I slowed down quite a bit, I was able to accumulate 4.88 additional miles to also set a new World Record for distance run in 12 hours.

Breaking two world records was special to me, but the truth is the most meaningful part of it is the journey getting to it. Spending nearly six years finding this day is what I will remember the most. Setting a goal, trusting the process, being grateful for the ups and learning from the downs is what truly makes it special. Much more so than setting a record. It won’t be long before someone else decides they want to take a journey and inch us even closer to finding out how fast a human can run 100 miles. It will be fun to watch.





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