Blog: Behind the scenes of the Four Day Marches research

It’s Tuesday, 6:00 am. I am surrounded by an enormous crowd. Although I am definitely not a morning person, I feel surprisingly energized as I cross the Waalbrug at this early hour. It feels very special, yet I'm sharing this moment with about 45.000 people. And we are not even the only ones: countless supporters are cheering us alongside the route, making me feel even more special. It makes me realize I am about to do something extremely difficult. A true challenge for the human body, or maybe too much of a challenge? Are we perhaps approaching, if not exceeding, the physical limits of our bodies?

To answer such questions, the department of Medical BioSciences of the Radboudumc organizes the Four Day Marches research, every year since 2007. With over 45.000 participants from all ages, this walking event provides the perfect study sample for research about exercise physiology. This year, the research team aims to investigate the heart rhythm disorder atrial fibrillation and the influence of walking exercise.

In people with atrial fibrillation (AF), the heart beats rapidly and irregularly from time to time. In general, AF is a relatively mild condition, but during episodes of AF, patients can experience symptoms like palpitations, dizziness, or shortness of breath. In addition, people with AF have an increased risk of stroke. The ultimate goal is therefore to minimize the occurrence of AF, but how?    

The Four Day Marches research team investigates if walking exercise is the answer. They were not only interested in the impact of walking the Four Day Marches itself, but also the training period leading up to it. They hypothesized that this training period has a beneficial effect on AF, whereas the Four Day Marches itself might not, due to its intensity. To study this, the research team included 130 participants with AF, of which 60 walked the Four Day Marches, and the other 70 were controls. During the training period, participants wore heart rate monitors that can detect episodes of AF. During the Four Day Marches itself, participants wore this same monitor. In addition, they came to the research center after every walking day for multiple measurements, including echocardiography, blood pressure, and blood withdrawal. 

To provide some insight into the ‘behind the scenes’ of the Four Day Marches research, I talked to this year’s study coordinator and PhD candidate Liz van Hout about her research, the organization of the event and her own experience. After a short break to recover from this week, Liz and I met at the department of Medical BioSciences, where we both work. She provided some insight into the organization and preparations for this study. “Exactly one year ago, during the Four Day Marches in 2024, we had our first meeting”, she said. “Of course, a lot of work goes into the request for ethical approval and the recruitment of the participants. We screened around two hundred people by phone.” The list goes on and on. “Also, during the Four Day Marches, you need about fifteen employees per day, so making the planning for personnel can be quite challenging.”

Next, she elaborates on her experience regarding organizing such a massive event. “It involves a lot of project management. It also makes a huge difference if you know what to expect. I don’t live in Nijmegen, and before, I had only been to the Four Day Marches once, so that definitely added to the challenge.” I ask about her favorite moment of the past week. “One moment, two participants recognized each other from their childhood. It was nice to see that this event connects people, and that participants enjoy taking part in research. Also, the festive Four Day Marches atmosphere in the research center makes it a unique experience. All participants are cheerfully sharing their stories and experiences.” 

Lastly, I ask Liz what she gained from this experience. “I realized that I am not a micro-manager, not at all!” she laughs. She also mentions that, most importantly, you have to like organizing such events. When I ask her if she does, she answers that she looks back on it positively, but next year, she wants to walk the Four Day Marches herself. 

This little sneak peek into the Four Day Marches research makes me realize that the walkers may not be the only ones deserving a ‘Kruisje’. It was a true team effort that made this week such a success. Whether you are practicing science, walking, cheering on walkers, or partying every day (let’s be honest - that’s also a huge accomplishment); everyone puts their best foot forward. As a researcher, I’m very curious for the results of this study: are we really pushing the limits of our body during the the Four Day Marches? Either way, I’m excited to take those 216.437 steps again next year – although, for now, I’m happy to set my alarm at 7:00 am again. Whatever your role will be, hope to see you (again) next year!

-

A blog by Kim van den Nobelen (PhD candidate @ Dep. Medical BioSciences)
Jr. editor for Radboudumc Research Institute for Medical Innovation