In what was a fairly last-minute decision to race, American Anne Flower lined up for the 2025 Tunnel Hill 50 Mile and set a new women’s 50-mile world record of 5:18:57. The record, set on November 8 on the flat and fast course in Vienna, Illinois, comes less than three months after Flower broke Ann Trason’s 31-year-old record at the Leadville 100 Mile, her debut run at the distance.
We caught up with Flower, an emergency room doctor, on her way home to Colorado Springs, Colorado, the day after her record-breaking run. In the following interview, Flower talks about why she thinks she was better suited to Tunnel Hill than Leadville, how her life has changed since her Leadvillle win, her decision to race Tunnel Hill instead of the Indianapolis Marathon, her pacing strategy, and how her mom — as her only crew person — was integral to her success. She also shares some of her future racing plans.
You can also read more about Flower and her Leadville 100 Mile run in our in-depth profile of her from September 2025.
Before jumping into the interview, it’s worth noting that Flower’s run was the first of several impressive performances by women at the event: Caitriona Jennings of Ireland set a new women’s 100-mile world record at the Tunnel Hill 100 Mile — read our post-race interview with her — and American Courtney Olsen set a new women’s 100k American record.
Anne Flower setting a new women’s 50-mile world record. Photo: Micki Colson/Colson Photography50
[Editor’s Note: The following interview has been lightly edited for clarity.]
iRunFar: It’s the day after your world record run at the 2025 Tunnel Hill 50 Mile. Congrats! How are you feeling, physically and mentally?
Anne Flower: Yeah, I feel pretty good. I think I felt better this morning when I woke up. I was able to go for a walk around the neighborhood and move my muscles, and then I just sat on an airplane for a couple hours, so getting up out of the airplane seat was very uncomfortable, but I feel good overall. It’s been a long time since I’ve run a non-mountainous race, so it’s easy to go up and down stairs and that sort of thing, which is just really exciting.
iRunFar: You’ve had a season of record-breaking runs. First, you broke Ann Trason’s 31-year-old record at the Leadville 100 Mile less than three months ago in August, and now you set a world record at 50 miles. You’ve done really well at a lot of small races in the past, and then to have two runs of such magnitude. How does that feel?
Flower: It’s really exciting. Yeah. I think, honestly, Tunnel Hill probably fits my characteristics as a runner a little better than Leadville. Leadville will always be this just phenomenal surprise of “How on Earth did I do this faster than most?” But no, it’s been incredible. I don’t know that I wish I would’ve signed up for bigger races earlier. I think at this point in my life, this is where I needed to be to get to this level of maturity, and it’s been amazing. It’s been awesome.
iRunFar: What makes Tunnel Hill a better race for you than Leadville?
Flower: When I started running longer distances, I was running road marathons. And so I think I became very comfortable with very economic running where I don’t work very hard to move forward. My feet don’t come off the ground very much. I’m a lazy runner, but I can do it pretty fast. I was pretty quick at road marathons. So it makes sense that as I started to go longer, something like Tunnel Hill would be a good fit because it’s just like 1.9 marathons, but flat and fast and super fun.
iRunFar: When we last talked, I asked you if you thought your life would change after your win at Leadville. And I just wanted to follow up on that. Has your life changed, or has your relationship with running changed at all since that happened?
Flower: I think it has. I think I’m way more excited about running than I ever have been, honestly. And I wasn’t sure exactly where my priorities would be in terms of looking at 2026, but I think that after some soul-searching and some discussions with my husband, I’m pretty all-in to see where this goes for the next months to a year to see what other races I might be able to get into and what might be possible. It’s also been really cool. University of Colorado Health picked up the story, and it was distributed to all of the nurses and doctors that I work with.
And so there have been some really fun conversations with people who either tell me what they’re doing in their running lives, like, “Hey, I wanted to let you know I ran a 5k last weekend, never thought I could.” So, it’s brought a lot of collegiality with my coworkers, some of whom I’ve never spoken with before. So, it’s been a really great point of connection, because everyone runs or knows someone who runs or knows something about running. It’s been really fun.
iRunFar: When did you set your sights on Tunnel Hill?
Flower: I knew it was very fast, and I knew that I needed to get to Ohio to visit my family. My grandma turns 97 this week, so I knew I needed to get back before winter and before life got crazy. So, I actually was signed up maybe three weeks ago to run the Indianapolis Marathon. It’s fast, it’s fun. It would give me something to do and a reason to go back to visit family. But then as I was looking at it, I was honestly nervous that I might hurt myself trying to run a very fast road race just because I’m in far more mountain-running shape than I am fast road marathon shape. I’ve had some hamstring issues and just didn’t feel really confident with it.
I knew that Tunnel Hill was the same weekend, and so I reached out to Steve Durbin, the race director, and he was super gracious and super helpful, very encouraging, and helped me with an entry, and the rest was good.
iRunFar: So, is it fair to say that maybe you didn’t do any specific training for this, or were you training for a marathon and that just carried over to this?
Flower: A little. After Leadville, into September, I knew I wasn’t quite done with the season, but I didn’t know what I was looking toward. I thought it would be something fast, so I had already started doing more fast, flat training. My good friend who I run with, Hannah Allgood, is training for a fast 50 miler in a couple of weeks, so I was just doing her workout one or two days a week, which involved some fast, flat splits. And then once I knew I was doing at least a marathon, then I started doing more speedwork to make sure that my legs would be ready. But I think endurance-wise, I think I was ready no matter what. It was just making sure that I felt comfortable with the leg turnover required to run something fast.
iRunFar: Did you always have the world record in mind going into this, or what were your goals? What was your mindset heading into Tunnel Hill?
Flower: Yeah, so I’ve been talking to some friends and people who give me good advice about running, and my main goal was to go under six hours. I thought if I went under six, I would be super happy with that. That would be one of the faster times at Tunnel Hill. It would probably get me on the podium of the USATF 50-Mile National Championships. That would be super awesome. Then I got a couple new pairs of shoes and I was testing them out on the Santa Fe trail where I live, which is pretty flat. And my splits were just awesome. It almost felt like I was cheating doing my workout because it didn’t feel nearly as hard as the rest of the season had been. And then once I got to Cincinnati, which is where my parents live, I went for just a shakeout run. And again, my times were pretty exciting and fast.
And so, then I started to think, “I think this could be interesting if all of us go out at around 6:30-minute miles and see how long we could hold it.” Des Linden was supposed to be there, and I’d heard that she was going for 6:30 as long as she could, but then she wasn’t able to make it after a big New York City Marathon week. So, I had 6:30 in my mind as a good pace.
iRunFar: I feel like you ran that pace the entire time. Were you looking at your watch the whole time, or were you going more by feel?
Flower: A little bit of both. The first mile was actually one of my slowest, and it was very uncomfortable. I was ready to run, and I thought that the women’s lead pack would be going out at at least 6:30s, right? You should start fast, so you have a little time to make up at the end if things start to go downhill. But there was no one around me, and I did a 6:40, and I was like, “Oh, this does not feel good.” And so, I decided to go a little faster, catch a couple of the men, and see where it went from there. The first marathon felt so good. One, I was excited to be there. I was fueled, I was rested. It’s downhill for the first 13 miles. You do a turnaround and you come back to the start before you head north for the second half. It just felt really, really good. So, through that, I knew that my splits were pretty good. I think our first marathon was something around 2:46, 2:48. It felt awesome.
iRunFar: Did you feel pretty good the whole way, or did you have any particular high points, or low points, or difficulties?
Flower: Yeah, I think the low point, honestly, the first mile just felt so awkward. I was just concerned that I had a bad plan, but I don’t think there was a woman ahead of me after the first five steps, which is never a great feeling. Mile 40 to 45 was the lowest point for sure. Everything was just getting achy. My toes hurt, areas of my glutes were hurting. It was pretty late, so I was trying to do the mental games of a marathon, where it’s like, “Okay, so I’m already at mile 20, mile 22. I know for a fact that it’s just the kick left.” But it was a little harder doing that with 10 miles to go. It was a grind.
iRunFar: Was there a moment where you felt pretty certain that you’d be able to hold the pace and get the world record?
Flower: Probably also at 40 miles. I was doubting myself, like, “Oh man, this is feeling really hard.” But I wanted to have 70 minutes to get under the record at mile 40. So, I was just doing the math in my head of, “Okay, if I can get to mile 40 by 4:20, then I’ll feel good that I have about 7-minute miles to get the last 10 done.” And I was pretty well under that, so I knew I could just go for it. And even when I was feeling terrible, my paces were still pretty good. I was barely over 6:30s for those miles that felt really terrible.
iRunFar: Yeah. Did you have a nutrition plan? What did you eat?
Flower: I think I actually did better nutrition-wise planning this race than I have any, historically. Tunnel Hill is awesome in the sense that you start in the middle and then you go south for 13 miles, turn around, come back to the start, north for 11 miles, turn around, come back to the finish. So, my crew was my mom, who’s awesome. She is just always excited to do whatever. She’s not the best directionally, so I was a little bit nervous, but I had put the GPS coordinates into her phone, and so she only had to meet me at three distinct locations to give me aid five different times.
I did really well on fueling right before I started. I took caffeine gel. I had some breakfast. And then every time I saw my mom, which was five times about eight miles apart, I had her fill up my bottle, I grabbed a Tailwind and a Neversecond gel, and that kept me going pretty well for the race.
iRunFar: I love that you put your GPS coordinates in your mom’s phone.
Flower: Oh, yeah. Otherwise, I don’t know if she would’ve made it. It’s straight, it should not be that hard, but anything that I can do to take that mental strain off of it … I mean, we had to get up at 5:15 in the morning and that sort of stuff. But she was awesome. She was perfect. I got to the first aid station, and she just had in one hand the bottle and one hand the gel, and the pit crew was awesome.
iRunFar: Is this the first time she’s crewed for you?
Flower: No. The first time I did a race in Moab, she came with me and just carried around a backpack that had stuff I might need in it. But at that time, I had no idea what I was doing either. It was my first ultra. So, I think she had just snacks in the backpack plus a change of socks if I needed them. But she made it to the 35-mile point, and that was when I saw her.
iRunFar: That story wins the day.
Flower: I know. I told her, I was like, “You’re retired. Your name’s going to get out there.”
iRunFar: Professional pit crew.
Flower: Seriously.
iRunFar: Anne’s mom.
Flower: It’s true.
iRunFar: Before Leadville, you mostly raced 50-mile and 50k events. I feel like you told me that you really liked that shorter distance. And then you jumped up to 100 miles with Leadville with huge success, and now you’ve come back down to 50. So, you’ve done the whole range now. For you, how do the two distances compare and contrast? What do you like and dislike about each?
Flower: Running 50 miles flat was a very unique challenge because I haven’t run a race in years where I had to just do the exact same footstep over and over and over again. I mean, at Leadville, you hike, you climb, you go up, you go down. It’s so much variability, but this was so repetitive, which is great because you can really settle into a pace and a plan and that sort of thing. But then it’s also challenging because it’s the exact same footstep over and over and over. I still prefer mountain events. I like changes of scenery. I like changes in terrain and altitude and that sort of thing. But yeah, it’s nice to recover from 50ks and 50 milers. It feels a little gentler.
iRunFar: Last question. You had two really big runs in the last three months, and I never like to ask what’s next, especially the day after the event. But what are you most looking forward to in the coming months?
Flower: Yeah, I think I’m going to do a couple of 100ks late winter and early spring.
iRunFar: Can you share which ones?
Flower: I think probably Black Canyon 100k and maybe Canyons 100k.
iRunFar: Is there an ulterior motive to racing those events?
Flower: I think I need to finally show up to events where I need to compete against people. So, I’m thinking Black Canyon should be good. I’ve heard Molly Seidel of Olympic marathon fame is planning to be there, plus some very, very fast trail women. So, I’m excited to go up shoulder to shoulder, see how it goes.
iRunFar: I’m very much looking forward to seeing you race those events.
Flower: Thanks. It’ll be interesting with ski season. I guess I’ll try to do more uphill skiing this year compared to normal where I just ski downhill all the time, but it’ll be good.
iRunFar: Fitness is fitness?
Flower: There you go. I know my quads will be so strong after ski season. It’d be great.
iRunFar: Well, congratulations on your new world record and I hope you recover well.
Flower: Thank you so much.
