Solidarity and environmental bibs
The purchase of a solidarity or environmental bib is an opportunity for runners to contribute to a useful and impactful project, while guaranteeing their registration for one of the Mont Blanc Marathon races in 2026 (without a draw).
Registration methods vary according to race number (see project descriptions below):
- In favor of the sports sections of the Club des Sports de Chamonix: registration opens on November 5, 2025 at 2:00 pm.
- Environmental bibs: registration opens on November 5, 2025 at 2:00 pm.
- In favor of the association Vaincre les Maladies Lysosomales: online pre-registration already open.
- In aid of Trail Runners Against Muco: write to tramuco1996@hotmail.com
- In support of the Ultra Sports Sciences research fund: registration link available soon.
Help preserve our environment!
Since the creation of the Cross du Mont-Blanc in 1979, the Club des Sports de Chamonix has been working to offer quality races while limiting their impact on the environment.
Today more than ever, climate and environmental issues are at the heart of our concerns. Through the sale of environmental bibs, our aim is to participate in an ecological movement that goes beyond the framework of our event, and to have a positive impact directly on our immediate environment.
In 2026, 40 environmental bibs will be sold, divided between the Duo Etoilé, the 23km, the 42km and the 90km of Mont-Blanc. The funds raised through these donations will directly contribute to financing local environmental initiatives.
REGISTRATION OPENS ON NOVEMBER 5, 2025 AT 2:00 PM
Support medical research and patient care!
Vaincre les Maladies Lysosomales
Since 2013, the Mont Blanc Marathon has partnered with Vaincre les Maladies Lysosomales, a patient association recognized as being of public utility, whose primary objective is to support research for the benefit of 60 rare diseases and to support patients and their families in their fight.
VML's raison d'être is based on an ultimate goal: the cure of people suffering from lysosomal diseases. The association has set itself three missions for the benefit of the greatest number of people:
- To advance research and improve access to care;
- To provide certified and appropriate scientific and medical information;
- Support and help families adapt to illness and disability.
With more than 500 solidarity race numbers and €300,000 donated to medical research in 12 years, the loyalty of Mont Blanc Marathon runners makes a real contribution to supporting scientific advances and developing new treatments.
In 2026, the Mont-Blanc Marathon will once again offer 55 solidarity race numbers in aid of VML, divided between the Duo Etoilé, the 23 km, the 42 km and the 90 km of Mont-Blanc.
Trail Runners Against Muco
The Mont Blanc Marathon has joined forces with Trail Runners Against Muco in the fight against cystic fibrosis, a genetic disease that mainly affects the respiratory and digestive systems.
For over 20 years, the Chamonix-based association Trail Runners Against Muco has been taking on sporting challenges to raise funds for Vaincre la Mucovicidose, including participation in the Mont-Blanc Marathon races. Their motto: "Let's give our breath to those who lack it, and together let's win life!"
By supporting Vaincre La Mucoviscidose, Trail Runners Against Muco contributes to the following objectives:
- Raise funds to support medical and scientific research aimed at finding more effective treatments and, ultimately, a cure for cystic fibrosis,
- Improve patients' quality of life by offering them appropriate support, helping them to manage their disease on a day-to-day basis, and providing them with social and psychological support.
- Raise awareness and inform the general public about the disease and its challenges.
In 2025, €38,000 in donations were collected thanks to the 30 solidarity bibs allocated to Trail Runners Against Muco. The entire amount was donated to Vaincre la Mucoviscidose.
In 2026, the Mont-Blanc Marathon will once again offer 35 bibs for TRAMUCO, divided between the Duo Etoilé, the 23km, the 42km and the 90km du Mont-Blanc.
Ultra Sports Science
The Mont Blanc Marathon has teamed up with Ultra Sports Science to support medical research into ultra-endurance sports.
Created in 2015, Ultra Sports Science aims to:
- Raise funds to set up international medical research,
- Transmit the results of this research to athletes, scientists, doctors, organizers and sports federations,
- Implement a health policy to prevent doping.
In 2026, the Mont Blanc Marathon will once again offer 25 bib numbers for the benefit of USS, spread over the 90km, 42km and 23km.
All funds raised will go towards a scientific study on the overall health of women ultra-trailers. This project will aim to better understand the physiological, hormonal and psychological specificities of women involved in ultra-endurance. An information conference open to the public will be held at the end of August 2026 in Chamonix, to present the objectives and initial thrusts of this research.
REGISTRATION LINK AVAILABLE SOON