Photos: Felix Sonnenschein / True Motion



For Felix Sonnenschein, running is about balance. “I recalibrate – physically and mentally,” says the 35-year-old when asked about why he runs. A lap through the city park? Sometimes not enough. With two school friends, Felix is looking for a new challenge. And finds it in a five-day ultramarathon through Jordan. Why he dries vegetables and does yoga in a hot and wet studio. A portrait.

Felix Sonnenschein is waiting for heat. Has been for days. Preferably 35 degrees Celsius in the shade, no humidity. In other words, for a really dry summer. But the sun is rarely coming out this year. “Right now would actually be the time to train really hard, to break a sweat, to feel the limits,” the 35-year-old says. It’s August 2023, and Felix Sonnenschein is currently in the peak training phase of his life.

As a kid, the Münster native was already a little track and field athlete. He loved running, especially the middle distances. 800 and 1,500 meters – that’s where he felt at home. Then, he fell in love with rowing. It wasn’t until school and university left no time for team sports and he sat at his desk more and more often for longer and longer periods of time that Felix found his way back to running. For balance.

“When I run, I recalibrate myself,” he says, “physically and mentally.” If he doesn’t exercise, he says, he becomes obnoxious. His family knows this, his friends and colleagues know this. He has always been that way, even as a child.

Today, the Felix works for a large retail company; he is responsible for building teams and developing new business areas that have been neglected in the past. “Finding new solutions and breaking new ground,” he says, is what he enjoys. “Just going at it and attacking.” Leaping into the unknown – that or a similar thought must have been on his mind last year.


At the time, he was hanging out with two old college friends. They were philosophizing, swapping weird ideas. “Our lives are good, we’re doing fine,” Felix recalls the moment. They were looking for a challenge, something that would push them to their limits. “We felt that we needed a new challenge,” he says today.

One of the three friends no longer lives in Germany. He works in Saudi Arabia – and there he learns about a physically and mentally extreme run: the five-day ultramarathon through the Jordanian desert. “That was perfect, exactly what we were looking for,” says Felix. The three sign up. Without ever having run an ultramarathon – let alone one in the burning desert sun.


“A triad,” Felix says, “is my motivation.”

The 35-year-old loves physical exertion, loves to test the limits. And sometimes to exceed them. To do so, he sets ambitious goals. “To somehow achieve these by my own efforts feels good to me,” he says. But above all, he is motivated by his will to prove something. “To myself, but also to those around me,” he says.

“It spurs me on when others say I’m batshit crazy.” People say such things for a variety of reasons. Usually because they can’t imagine certain challenges, they sound too crazy. “To show them that it can be done after all, to impress them like that, makes me proud. And motivates me.”


It is the beginning of 2023 when Felix starts looking for a coach. There are still ten months to go until the start of the race in the hot sands of the Jordan River.

The race in Jordan leads over 220 kilometers through the desert in five days, first 38, then 40, on the third day 60, on the fourth 48, and finally 34 kilometers. “The cut-off time,” says the Münster native, “doesn’t worry me.” Runners get 1:45 hours to run seven kilometers. Nevertheless, the loads are extreme. And unprecedented for Felix.

“I needed someone who knew the distances, the challenges, physically and mentally,” Felix explains his choice of coach. He picked someone who had won ultramarathon titles himself just a few years ago. He develops an individual training plan for Felix.

It starts with long distances at a very slow pace. Felix wants to prepare his body, muscles, and tendons slowly for the increasing load. This works well for the first few weeks. Then come the double units on the weekends. The load increases. And it increases further.

Pain or even real injuries? “I never knew any of that,” says Felix, “until I started the intensive preparation for Jordan.” The extreme, constant loads overstrain Felix’s body. First his calf and Achilles tendon hurt, then it’s even worse in the morning. The tendon under his foot, the plantar fascia, hurts so much that he can hardly get up.


Felix goes to see a doctor. The diagnosis is plantar fasciitis – presumably triggered by overloading, a so-called overuse injury (read Chapter 4 (Part 1) to find out why we injure ourselves while running and what role overuse injuries play in this). Physical therapy is supposed to help. But the pain remains. And the training often becomes torture.


At an event, Felix hears about True Motion and talks to co-founder Prof. Dr. Gert-Peter Brüggemann. He tests the U-TECH Aion, runs with the shoe. “I feel that sinking in relieves my plantar fascia,” he says. “Every step is cushioned, and the load is evenly distributed.” The U-TECH Aion helps Felix get back into training, preparing for the heat battle through Jordan.

To relieve the strain on the tendon as much as possible, the 35-year-old also wears his running shoes throughout the day. In addition, he stretches every day, morning and evening. Shock wave therapy also helped relieve the pain. “With the U-TECH Aion, I can run again, pursue my goal again,” says Felix.

The only thing is – the weather is not playing along.

In the meantime, it’s summer in Germany. Felix and his coach are planning to simulate desert heat. He is supposed to train at 35 degrees Celsius, to run in the burning midday sun. Conditions that also prevail at the Jordan River. But the sun – it doesn’t shine. “This summer just didn’t want to be a summer,” says Felix. They start searching for an alternative.

Instead of running through rainy Münster, Felix ends up running to yoga. A humid, wet studio at 39 degrees Celsius replaces the dry desert air. On the schedule is hot yoga. “It’s not a run through Jordan, of course,” Felix says. “But I can still prepare my body a little for the heavy strain in the heat.”


He also has to prepare his meal plan. Not only because a five-day endurance run at more than 30 degrees Celsius in the shade burns thousands of calories. Especially because there is no food provided by the organizers at the camps. “Everything you want to eat, you have to bring with you and get yourself beforehand,” the 35-year-old tells us. The only service is the transport of food from night camp to night camp by the crew. Cold chain? No way.



By night. And by day. When the world hushes to a whisper and we feel the thrill of endless possibilities. When we start at our front door, running through streets and woods. When summer blend into fall, when we run through water and jump above sticks and stones, when exploring new ways. No matter what. Then we run wherever and whenever we want. Meet the new U-TECH Nevos Elements next gen. 

Felix spends weeks figuring out what he can transport and how he can keep the food. He informs himself about nutritional values and how they stay in the food, buys a vacuum device. He begins by drying various fruits and vegetables, placing them in the oven at 50 degrees Celsius for five hours. He then vacuums the dried food – and leaves it out in the blazing sun for hours.

“I wanted to test what happens when food is exposed to heat for hours,” says Felix. “I wanted to know if I can I still eat the stuff after five days in the desert.” He can. Felix’s meal plan has now been in place since early August.

Every morning, he has oatmeal with flaxseed and spelt bran, plus peanut butter and dried apricots. Along the way, Felix replenishes his energy reserves with energy bars – until the evening, when he eats vacuum-packed vegetables that he has dried himself. Accompanied by couscous or risotto. With nuts, Felix then catapults his calorie intake to around 4,800 calories per day. “Through this project, I’m not only getting to know my limits even better,” says the 35-year-old, “I’ve also noticed how much fun it is for me to prepare food and experiment with it.”

Jordan is to be all about fun; finishing times are completely beside the point. “I just want to make it to the finish line,” Felix confesses. It’s his first adventure, his first challenge of this kind – and yet at the same time training for an even greater goal. In July 2024, the Münster native will compete in the Challenge Roth triathlon event. His times will matter then. More precisely, seconds. “To stay under nine hours – that’s my big goal,” Felix says. He will start to get ready for this in the Jordanian desert at the beginning of October.



Almost 100 % of our technology is derived from scientific findings and biomechanical research. Prof. Dr. Gert-Peter Brüggemann, head of the Institute for Biomechanics and Orthopedics at the German Sports University Cologne for decades, is largely responsible for this. Over the past 25 years, he has been part of numerous innovative running shoe developments – and thus a sought-after expert among the giants of the industry.





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