News items 4Days Marches Research 2024 focuses on proteins and walking crookedly

5 July 2024

This year, the 4Days Marches research focuses on various studies, with a standout investigation into why some participants walk increasingly crooked during the march. Additionally, Radboud university medical center exercise physiologist Maria Hopman and her team are researching different types of proteins that should promote muscle recovery. In the event of a heatwave, there will also be a follow-up study on the effects of wearing white and black clothing.


As people age, they lose more muscle mass. How can muscle mass and strength be maintained? Proteins are part of the solution. Consuming sufficient protein, spread throughout the day, positively affects muscle recovery and mass. Hopman explains, ‘Active seniors are advised to consume more protein. Our previous research among 4Days Marches participants showed that about half do not meet this recommendation.’

Therefore, she is starting a study where participants over 60 years old will consume extra proteins, either in the form of plant-based or animal-based powder or protein-rich supermarket products. There will also be a control group. Muscle damage and soreness will be measured after each walking day. The results are relevant to all seniors, says Hopman. ‘The decline in muscle mass is universal. Moreover, people are living longer. If we know which form of protein intake best helps maintain muscle mass, everyone benefits, both walkers and non-walkers.’

Walking crookedly

Every year, some walkers develop an increasingly uneven gait as the Four Days Marches progress. Some are unaware of this, raising the question of what causes this misalignment. Hopman wants to investigate this issue this year with colleagues from Orthopedics and Neurology. ‘One possible explanation lies in the spine and muscle fatigue. At the same time, you would expect people to feel this, but that’s not always the case. Therefore, we will also conduct several neurological tests on the participants,’ says Hopman. She hopes this will provide more insight into the cause.

Black or white clothing

When temperatures exceed 30 degrees Celsius, Hopman wants to revisit the question of which clothing color—white or black—is more comfortable during exercise. ‘We will only conduct this study during a heatwave. Last year, temperatures reached a maximum of 25 degrees. We saw no difference in skin and body temperature or perceived heat between white and black. We want to know if this changes when it’s over 30 degrees,’ says Hopman.

In this scenario, participants will alternate between wearing white and black clothing on different walking days. Researchers will measure the effects on the body, including skin and body temperature. Previous Four Days Marches research showed that body temperature rises by about 1 degree Celsius during a walking day. The new study will determine the role clothing plays in this.

About the 4Days Marches Research

This year marks the 16th 4Days Marches research event. Professor of Physiology Maria Hopman and her team will be stationed at the research center near the start and finish location of the 4Days Marches, at the Wedren in Nijmegen. Here are some highlights from the past 15 years:

  • The first walking day is the most physically challenging.
  • Body temperature increases by 1 degree Celsius during a walking day.
  • 20% of walkers drink too little during a walking day.
  • Heart damage occurs after a walking day and may predict cardiovascular diseases.
  • Type 2 diabetes patients need less medication as they train more for the 4Days Marches.
  • Walkers around 80 years old are estimated to be 8.2 years younger in biological age.
  • Walking 30-40 minutes a day reduces the risk of cardiovascular diseases.
  • Statin users do not experience more muscle pain and damage after a walking day than other walkers.
  • The older the walker, the poorer the thermoregulation.
  • Extra vegetables lower blood pressure in walkers with hypertension.

On this photo: Maria Hopman.

More information

Pauline Dekhuijzen

wetenschaps- en persvoorlichter

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