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Zach Bitter Sets New American Record for 100 Miles

Although he fell short of his attempt at a world record, California ultrarunner Zach Bitter lowered his own American record for 100 miles on Dec. 19 at the Desert Solstice Track Invitational in Phoenix. Bitter, 29, ran 402.5 laps on the track at Phoenix Central High School in 11 hours, 40 minutes and 55 seconds—an average pace of roughly 7:00-minute mile pace—to break the previous mark of 11:47:21 he had held since 2013. He had been shooting for the world record of 11:28:03 and had been ahead of that pace early on—passing through the 50-mile mark in 5:33:30—but struggled over the final 15 miles.

Bitter, who lives in Davis, Calif., also lowered the American record for 100K on a track to 6:58. (The previous 100K track record of 7:00:12 had been held by noted scientist and author Bernard Heinrich since 1985. Max King holds the absolute U.S. 100K record, having run 6:27:43 to win the IAU 100K World Championships in 2014. Bitter placed sixth in that world championship in 6:48:53.)

The invite-only event in Phoenix also had a 24-hour running event happening concurrently, and Pete Kostelnick, 28, of Lincoln, Neb., won that by running 163.5 miles—the fifth highest total in North American history and the second-longest 100-mile track run in 2015, according to Kostelnick was also the runner-up in the 100-mile competition, covering 100 miles in 14:08;12. The top women’s finisher in the 100-mile event was Katalin Nagy, 36, of Sarasota, Fla, who placed third with a 14:41:59 split. She also went on to set a new American record for 200K in 19:19:05 but eventually dropped out before completing 24 hours of running. (For complete results, go to

We caught up with Bitter, a 5-foot-9, 140-pound athlete with a 2:31 marathon PR and the 2015 U.S. 50-mile road running championship to his credit, to see how his record-setting day went. (Be sure to read our 2013 story on his original record, too.)

How do you explain to people—even marathon runners who don’t do ultras—about these kinds of events?

Most people don’t really understand what it means to run 100 miles in less than 12 hours, but usually I try to explain it by saying it’s close to running 3-hour pace for a marathon four times in a row. And that’s usually how people can relate to it. That’s usually when the light bulb clicks in their head and they start asking questions like “How did you do that?” or “Don’t you get bored out there?” You get a pretty wide variety of reactions. Some people will say “I would never do that” and then others will get motivated and want do run ultras. The people who are into ultrarunning will say that they’re inspired about their own running, which is pretty cool.

RELATED: 6 Tips To Get You Through Your First Ultra-Distance Race

How did it go out there running 402 laps around a track at 7-minute mile pace?

It was a fun day, minus maybe the last 15 miles. That was just horrible. I was hoping to break the world record and got out aggressively in the first 50. [Note: Bitter’s 5:33:30 split for 50 miles equates to 6:40-mile place.] But I think with 100-milers, you have to expect some regressions in pace. When I came through mile 80, I knew I needed to average 7:00-minute pace the rest of the way to get the world record. Had someone told me that at the start, that I would have been able to get to mile 80 and only needed to average 7:00-minute pace the rest of the way, that would have been great. But I think I spent a little too much energy in the beginning and that 7:00-minute pace wasn’t sustainable at that point.

I made one pretty decent push from about 80 to 85 where I got my pace slightly under 7:00-minute pace for quite a while, but then it got to a point where it became hard to keep it even under 7:30 pace. So it was around mile 84 or 84 is where it became clear that I would fall short of the world record. At that point, my goal was to stay steady so I could continue on and break the American record. I definitely went in there to get the world record but you can never really complain about a PR and an American record.

Was the final 15 miles more of a physical challenge or a mental challenge?

In 2013 when I set the American record, the last 20 miles was more of a mental struggle and less of a physical struggle so if I could get my head in the right spot I could always speed up a little bit. But this year it felt like mentally I was fine and could tell my body to push but my body didn’t want to go any faster, especially that last 10-15 miles or so.

What was your fueling strategy? (Bitter follows unique diet protocol called Optimized Fat Metabolization or OFM, detailed here.)

In training and in everyday life, I use a higher fat approach and use fewer carbs strategically so my body is more used to optimizing fat. Then on race day, I bring the carbohydrates back but I don’t need to use as many of them. During the race, I was using an Extreme Endurance product called Fuel-5, which has five different carbohydrate sources with different release rates. Some are designed for quicker release, some are for slower release. And then I also drank their electrolyte mix called Hydro-X. I was just drinking a scoop of each of those in about 12 ounces of water and sipping at that for a while. I mainly used Vespa Power Products (Vespa Juniors), Guayaki Yerba Mate Tea and a few random things off the main aid station table. I didn’t have any gut issues or digestive issues at all. I only stopped to use the bathroom twice during the entire event.

Overall, how does your body feel now?

Pretty good. I’m definitely a little sore. There is definitely a different type of soreness after (running 100 miles) on a track as opposed to a trail or a road. I can definitely feel the difference, but nothing outside the norm of what I would have expected to feel like.

What shoes did you wear?

I wore a pair of Altra One. I stuck with one pair of socks and one pair of shoes the whole time. I was initially sponsored by a running specialty shop and was able to run in all different shoes, but I started running in Altras a couple of years ago and that’s what I really liked the most. Now I’ve been running in Altras exclusively for a couple of years and then got on the Altra Endurnace team.

RELATED: How Zach Bitter Ran 100 Miles in Less Than 12 Hours

What does your training regimen look like?

I still follow a high-volume, high-mileage training program. I definitely periodize it and bring in some faster stuff when I get closer to an event. But it’s the same general approach I’ve been taking. My peak week of mileage coming into the Desert Solstice event was about 170 miles, but I was closer to about 120 miles for an average week. I also added in some tempo running and hills depending on how close I am to the event and what kind of event it is. This time around, I actually ran quite a bit on the track. I’ve realized that when you’re turning around a track at 7:00-minute pace or faster, you really stress those muscles differently. You can get injured pretty easily by not doing some track running. My go-to workout for this event was warming up by running 20 minutes to the track at just shy of 7:00-minute pace, then running 12 miles on the track that would end with a progression in which I would incrementally move down from 7:00-minute pace to low-5:00-minute pace. The thing I would change most about my training before my next track event like this would be to do some tempo runs at 5:45-5:50 pace for much longer periods of time. I think that could work in my favor for those last 15 miles, helping me keep muscular strength for the last part of the race.

What’s next on your agenda in 2016?

The last couple of years I definitely focused more on road and track events because that’s what I had for training (in Wisconsin). One of the thing I have learned is that specificity is definitely a huge factor in optimizing your performance in ultrarunning. But I moved to California this past summer and now that I have better access to trails, I will be doing some more trail events and a mixed bag of events going forward.

Right now the two big races I’m signed up for are the Lake Sonoma 50 and then the 90K Comrades Marathon in South Africa. I’ve wanted to run Comrades for a long time, but when I was a school teacher (prior to this year) it was always the last week of the school year and it was darn near impossible to schedule it.  I might also run the Black Canyon 100K to get a trail race in before Lake Sonoma.

PHOTOS: 2015 Lake Sonoma 50

Do you think you can go back and break the world record at some point?

Yeah, there’s definitely some excitement coming out of it, knowing how close I was to the world record. One of the things with these events is that, with all of the runners running in the 24-hour event, they’re running a lot slower and you find yourself in lane 2 quite a bit. You don’t know how that’s going to play out. You might get very lucky and won’t have to pass someone in lane 2 very often or you might have an event where you have to go out in lane 2 or 3 to pass people. But by doing that, you definitely add a mile to 2 miles. You know it’s going to happen going in and it certainly is a factor. If I can find an event and can run in lane 1 most of the time, that would likely be the difference.