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Meet the US’ first woman double-lung recipient triathlete

Knoxvillian Kassandra Klemenz hasn’t let cystic fibrosis hold her down since she was diagnosed — follow her athletic journey that’s breaking barriers.

Athletes in colorful gear compete in a triathlon run segment, focused and determined. Spectators cheer them on, lined by bright orange cones.

Follow the journey of this local athlete + how she got here.

Photo provided by Kassandra Klemenz

From having eight surgeries at birth + a cystic fibrosis diagnosis to striving toward the Olympics, Knoxvillian Kassandra Klemenz has been on one unique athletic journey.

When she traveled to nearby Chattanooga in May to compete in the Ironman 70.3, Klemenz officially became the first woman double-lung recipient + para athlete to complete a triathlon in the US. I sat down with her to chat about this achievement and how she got here.

Editor’s Note: This interview has been edited for length and clarity.

As someone battling cystic fibrosis since birth, what was it like growing up and beginning your athletic journey?
I was diagnosed at birth due to my stomach being ruptured, and I had to have eight different surgeries when I was born [...] indicating I had cystic fibrosis. I actually didn’t know that I was being raised really different because my mom and dad didn’t want to treat me different than other children, even though I was in and out of the hospital every three months.

Getting into competitive gymnastics was my saving grace; I was lucky enough to compete at an elite level where I could be homeschooled — I went to the gym basically from 8 in the morning to 5 at night, and then I did school after.

Around [age] 15, I injured my back in gymnastics and my neck — that’s why I’m considered a para athlete now. Due to my gymnastics injury in my left leg, some of my muscles don’t fire correctly.

A group of five people outdoors, some holding signs supporting organ donation. The mood is celebratory, emphasizing new life post-transplant.

Klemenz, now 30-years-old, didn’t receive new lungs until the age of 22.

Photo provided by Kassandra Klemenz

Fast forward to 2019 and your surgery, what were those months like from diagnosis to the transplant?
I kept getting more and more sick because I couldn’t exercise as much, my lungs kept getting more and more infections. Around age 20, they told me I would need a double lung transplant because I was in end-stage lung failure. I had to move out of state to be able to get my transplant, so I moved to Massachusetts for awhile.

I had three dry runs, where I got ready and was told it was time, but then at the last minute it was a no-go just because of issues with the lungs. That day they told me that I needed to go on a ventilator because my CO2 levels were too high and that they were going to peacefully let me pass away — and then they got a random call for lungs again.

I saw you had a rather quick recovery, almost immediately going on a hike. What was going through your head after that whole experience?
I got out of the transplant center about two weeks after, which is pretty quick for a double lung transplant. Being at the very bottom knowing that you’re about to die, you realize all these things that you wish you did and wish you could have done — I guess that’s where my mindset was.

I’m never going to have that excuse again. When I’m back there, I want to be able to say I had so many memories.

You began your running journey with a half-marathon in 2023, what caused that direction change?
I’ve always wanted to run, but I actually started out with mountain biking. I’m a Type A person + always need a goal, so I tried to get back into CrossFit and it was hurting my sternum a lot. I became a zipline guide four months after my surgery as well.

My husband saw I had all of this energy and said, “You have to find something to do.” So, he went and bought me a bike. And this was a little bit after, and you’re not allowed to ride a bike for a couple of years, so I had to stop riding. When we moved back to Knoxville (a couple years later), he said he wanted to buy me a mountain bike — I was like, “That’s how you progress into biking, is go straight to mountain biking.”

Growing up, I watched kids at school run track and wanted to do it, and [I] knew I couldn’t run long without coughing. One of my friends who lived near us said, “Come out with me on a run and whenever you want to stop, we’ll stop.” We ended up running six miles at a 10-mile pace, and I felt fine. So, I just kept doing it.

Then I did a trail run and popped my leg out of place. That’s how we found out I was a para athlete — it popped out so easily because of what is actually wrong with my left side.

A cyclist in aerodynamic gear and helmet rides a sleek bike on a road with lush greenery in the background, conveying focus and speed.

Klemenz said she had a lot of guys ask how she was so good at descending during the bike course in the Ironman 70.3, where she credited her mountain biking.

Photo provided by Kassandra Klemenz

Now having completed the Ironman 70.3, what was training like vs. your actual experience?
So, I believe if you want to be good, you get a coach and you learn from someone who knows better and who can do better than you. I feel like my coach’s training before was actually harder than the race — I actually didn’t go all out like we wanted me to, because the swim portion was canceled. I really wanted to get the full experience, but it was good because now we have numbers for me to play off of.

I loved the bike course. That was really fun and just very beautiful, it looks like it does in Knoxville. So, I felt at home during it and that was [a] nice feeling; usually when you go to other races it doesn’t feel like home to you and it gives you more anxiety. Chattanooga is definitely a race that suits me as an athlete and that I definitely want to pursue doing more and more there — I’m glad I got to do it on home soil in a sense.

What are your current goals?
In August, I will go to nationals, US 18 Nationals, for the Olympics and sprint distance for my para category. I think we’re actually gonna throw me in with the able-bodied people for the Olympic distance, just to see what I can do.

If I do well, I will continue to be looked at for the USA team. They have their eye on me and they think I have a lot of potential for the 2028 Paralympics.

Being a para athlete + a transplant athlete are very different. If I didn’t have an issue with half of my body, I would be able to compete regularly, but there’s no way I can compete at an elite level with the body issue I have. I want para athletes to get credit for what they’re doing, because they are working hard.

Any advice for aspiring athletes or someone with a health condition?
I definitely want people to realize that they can do it too. That if they really want it bad enough, they can do it as well, and it may take some time, but don’t give up on that. People expect things to happen very quickly and things in life don’t come quickly. So, just trust the process and don’t try to rush things; be mindful of your body and what you’re doing to it.

Talk to your doctors, and if you do talk to your doctors and they say it is out of the realm of possibilities, you can always scale that goal and it can still be a good goal for you to have no matter what.

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