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Jeff Tesselaar
World-Class Decathlete and Ambassador
Photography by Bjorn Paree
I am an ambassador for Del Ferro because I know exactly how much stress and uncertainty lies behind a stuttering challenge.
From Stuttering to Fluent Speech
Jeff Tesselaar had stuttered since the age of seven. Today, he ranks among the world’s elite in the decathlon, number 17 in the world, and speaks fluently.
“Being able to speak effortlessly now still feels like a liberation every single day,” says Jeff. “Two years ago I started with the Del Ferro method, and since then stuttering has no longer been a part of my life.”
The Search for the Cause
The exact cause of Jeff’s stuttering never became fully clear. “Research suggests that stuttering is often linked to trauma or an intense experience of anxiety. But in my case, that’s just speculation,” he explains.
“What is clear, however, is that for people who stutter, the diaphragm does not move smoothly. This causes the air to hit the vocal cords in a jerky manner, resulting in those interruptions in speech.”
Controlling the Diaphragm
During Del Ferro stuttering therapy, Jeff learned how to move his diaphragm fluently again.
“The method is entirely focused on gaining control over the diaphragm. Every morning and evening, I perform breathing exercises to maintain that control. Eventually, it becomes automatic, just like it is for fluent speakers.”
The course consists of five phases, Jeff explains. “During the first four phases, you are consciously working on the technique. That requires time and concentration, but what are a few months compared to a lifetime? In phase five, you speak fluently and automatically without even thinking about it. That is what it’s all about.”
An Athlete with a Mission
Jeff Tesselaar started athletics at the age of twelve. “I didn’t struggle with it much during training, but outside of sports, it was a different story,” he says.
“I love talking and socializing, but because of the stuttering, I actually avoided those moments. I came up with all sorts of tricks to mask my stutter—until I couldn’t anymore. At school, I hit a wall during a presentation. That was the moment everyone suddenly saw it.”
As Jeff began to focus on the highest level of sports, his stuttering started to get in the way there as well.
“During competitions, I sometimes thought: if I win, they’ll put a microphone under my nose, and everyone will hear me stutter. That fear prevented me from performing freely.”
Choosing a Stutter-Free Life
“At twenty, I decided: this has to stop. It was limiting me in everything—my sports, my studies, my future. I wanted to reach my full potential, and I knew that was only possible if I could speak freely.”
With the Del Ferro Method, he succeeded. “Finally, I could say what I was thinking, without fear. I wish that feeling for everyone who stutters.”
A Message of Hope
As of 2025, Jeff Tesselaar is an ambassador for the Del Ferro Institute. “I want to share my story so that others don’t have to go through the same thing. I was once told that I would never get over it—that I had to learn to live with stuttering. But that is simply not true. You CAN overcome it. I am living proof.”
“What people see, someone getting stuck on words, is just the tip of the iceberg. Beneath the surface, there is so much tension, uncertainty, and sadness. That’s why I tell my story. Because who knows, maybe one day we can retire World Stuttering Awareness Day, because no one will need it anymore.”