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Chasing His Limits, Altra Runner Zach Bitter Breaks 100-Mile Record

Professional Altra runner Zach Bitter breaks the 100-mile record on a track

Altra-sponsored endurance athlete Zach Bitter set out to test the limits of both his body and mind in August when he lined up on the track at the Pettit Center in Milwaukee, Wisconsin to break the 100-mile world record. Almost half a day later, he crossed the finish line, setting the new record at 11:19:13.

Here's how he did it.

Training for 100-mile races takes a lot of time. What do you do when you’re not running?

Outside of running, I do a few things. I work part time for my main sponsor Altra Footwear, coach and consult athletes of all sorts, and co-host a podcast called Human Performance Outliers. I jokingly tell people I can't do any one thing for more than 20 hours a week, so I cycle a few projects at a time.

Tell us about your race-day kit. Which Altra shoes did you wear and why? And what clothing did you wear?

On race day I chose to wear the Altra Solstice. The Solstice is what I would describe as an aggressive trainer or beefy racing shoe. The Solstice has a bit more room in the toe box than the Vanish, which is a true road racing flat. So since I was going to be on the track for 12 hours, I opted for the extra space that the Solstice offers.

My singlet was the Altra Men's Singlet 2.0, and my shorts were the Altra Split Short. I chose these options mostly based on comfort and blister protection.

Professional Altra runner Zach Bitter finishes a 100-mile run on a track

In a recent interview you said you’re interested in discovering “how fast a human can run 100 miles.” Why does this interest you?

It is mostly born out of curiosity. My interest has somewhat evolved since I ran my first event like this at the Desert Solstice Track Invitation in 2013. That day I was targeting the 100-mile American record. I had some success there, breaking the American 100 mile record with a time of 11:47:13.

After that race, I began looking more into the history of fast 100-mile performances. I found that the current world record holder, Oleg Khartinov, had it with a time of 11:28:03. I was optimistic that I could get my time down near that with the right training and race. This led me to become curious about exactly how fast I could run 100 miles in general outside of the current world record, which fed into the curiosity of what the limit of human potential is for an event like this.

Essentially, it left me with two goals: the 100-mile world record and where I could personally get to. In all honesty, I think we have the talent in the North American ultra community alone to dip well under 11 hours for this event. My hope is that some of the performances I have had will generate enough interest to really see what is possible.

After setting your new personal best and 100-mile world record, what’s next? Do you think you can run it faster and, if so, are you going to try?

My 12 hours at the Pettit Center was definitely my most well-executed 100-mile performance to date. I actually negative split (second 50 miles was 2:03 faster than my first). It gets harder to find spots to shave some time from a race like that, but I do believe there is some room for improvement.

Two decent ones that would happen without having to speed up at all would be a bit more efficiency on bathroom breaks, and the second doing an event that is specifically designed for a fast 100. The Pettit Center was an ideal environment for chasing a record, but it was in the middle of a 24-hour and 48-hour event, so I found myself in lanes two and three quite a bit to pass people.

I spent approximately four minutes using the bathroom. Had I run in lane two the entire time, it would add somewhere in the neighborhood of seven meters per lap, which doesn't seem like much, but it adds up when you do it a couple hundred times.

Bathroom breaks are somewhat inevitable, but my most efficient day was at the Desert Solstice Track Invitational in 2015. I stopped twice for a total of 60-90 seconds at that event. If I can dial these variables in a bit tighter and find a bit of improvement in overall pace I wouldn't rule out going under 11 hours for me personally. I will definitely be doing more of these events in the future. The biggest difference going forward is I may just be a bit more picky about what events and where I do it.

I know people struggle with their left side after a single hard track session. How do you manage to keep your body feeling OK through so many laps?

I lean pretty heavily on specificity of training for this. My weekend long runs for this event were all done on a track so I could get my mechanics used to the frequent turns.

I also believe building very strong lower legs is almost a must for something like this. I treat my feet and lower legs like any other muscle in my body. This is one of the reasons I do so much training and racing in lower profile shoes. Letting my feet and lower legs gradually build up to this certainly took some time and dedication, but it puts me in a position to have my feet and lower legs nearly bulletproof.

Professional Altra athlete Zach Bitter eats during a 100-mile race

You undoubtedly had to push through some low moments out there. What was your lowest point during the race like and how did you manage to bounce back?

Historically, I have never negative or even split a 100-mile race. That made things a bit psychologically interesting when I split 5:40:38 for the first 50 miles. I knew when I was in the mid-40 mile range that my split would be around there. This was a bit of a mental road block to get past, mostly because I had to convince myself I could even split, or at least come close to it.

I find that when negative thoughts creep it my lap splits reflect it. I started noticing my lap splits slipping a bit. Thankfully, I recognized what was happening, and I started focusing on small chunks of distance and working back into the pace range I wanted. After stringing a few solid laps together I let that momentum carry me a bit.

It was likely a bit easier for me since I certainly have a number of situations where I wasn't able to stay focused enough to keep pace. This gave me a lot of motivation to not let that happen again.

When I got into the late 60-mile range, I was within the distance of my longest long run for this event. At that point I did a self assessment of how my body felt and where my energy levels were at. Things felt OK all things considered, which gave me the confidence to trust my training and wrap my ahead around what I convinced myself was just one more long run.

What would you tell someone who is interested in dipping into the ultramarathon world or, more specifically, the 100-mile world? Maybe your top three pieces of advice?

Endurance is definitely a patient person’s game. It can be easy to look at what other people are doing and get too hung up on replicating their training or nutrition.

Working from where you are and gradually building up your training is smart. I like to call it micro-stressing. It can be easy to head out and try to do all the big workouts right away, but if you take your time and gradually stress your body consistently, the long term outcome will be much more sustainable.

I also think people should put a bit of time looking at what type of running they want to do. Ultra has such variety in distance and environment, I always encourage people to pick a race that excites them and puts them into an environment they will enjoy training for.

At the end of the day, even a 100-mile race is a very short period of time compared to the amount of time spent preparing, so you might as well enjoy it.

Follow Zach

Instagram: @zachbitter

Twitter: @zbitter


By Ashley Arnold. Ashley is a storyteller, ultrarunner and cat person. As Fleet Feet’s content marketing manager, she manages the Fleet Feet blog and its roster of writers.

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