
An ecofriendly Marathon
Since the creation of the Cross du Mont-Blanc in 1979, the Club des Sports de Chamonix has been committed to offering quality races while limiting their impact on the environment. With this in mind, each year we assess our environmental impact and implement a number of strong actions, which we reinforce from one year to the next.
Reducing waste and promoting rational use of resources
Since 2021, still and sparkling water bottles have completely disappeared from our refreshment stands, thanks to an ingenious production and distribution system developed by our technical team. Thanks to a financial investment of €50,000, the use of 50,000 plastic bottles has been avoided (every year!).
In 2024, we're going one step further by also doing away with plastic Coca-Cola bottles: we're now offering runners the chance to mix Coca-Cola syrup with the sparkling water we already produce.
All single-use containers have also been eliminated since 2017, with each runner required to bring his or her own reusable cup, bowl and spoon.
"By 2024, all plastic bottles have been removed from our refreshment stands."![]()
In collaboration with SITOM (the valley's waste sorting center) and the Ecotrivelo association, we sort recyclable and non-recyclable waste and provide compost buckets for bio-waste. The volunteers in charge of our refreshment stands are made aware of this issue and ensure that runners comply with the sorting instructions. So, 85% of our waste is organic and composted in Chamonix.
Since 2011, we have used only eco-responsible chip toilets, which require no chemicals or water supply, and whose waste is entirely biodegradable.
When registering, runners can choose a vegetarian meal option, must offset their carbon footprint linked to their transport, and tell us whether or not they would like to collect a T-shirt. We have also replaced the trophies formerly offered to runners with diplomas and gifts that are eco-responsible and/or consumable.
We also prefer to purchase large quantities of minimally-packaged products with recyclable packaging. We keep paper-based administrative procedures to a minimum, with online registrations and a reduction in the number of paper documents required for race number delivery (digital system).
Last but not least, our teams of closers are responsible for cleaning up all the trails after the runners.
Favoring organic and local products
Buying organic and local products is also a matter of course for us. For 2/3 of our purchases, we use local producers and retailers: among others, our tommes come from the Montroc farm and the Vallorcine farm; our sausages are supplied by Salaisons du Mont-Blanc; we work with Brasserie du Mont-Blanc for the beers served at race arrivals; our fruit is organic and bought from local early fruit growers; the bread, sandwiches and cakes come from local bakeries; and the hot dogs and diots are prepared by Viret, a local caterer.
For the Emosson refreshment station, the only one in Switzerland, we also use local producers: Ferme des Lisats, Duay & fils, and Boucherie Chanson.
Trophies in line with our commitments
Since 2024, the trophies awarded to the winners of the various races have been manufactured by Pahapa, a young company made in Chamonix. They are made from bio-sourced corn, are recyclable and industrially compostable!
Reducing the carbon impact of transport
The environmental impact assessment we carried out for the 2023 event showed that 96% of the Mont Blanc Marathon's carbon impact was linked to the transport used by runners and their companions. prior to the event to get to Chamonix.
We therefore encourage runners to use eco-responsible public transport such as the train (by sending out information on this subject in particular), and we require participants to make a donation to a local environmental project to offset their carbon emissions.
In 2023, over 2,000 runners chose to offset their carbon emissions, raising €5,000, all of which was donated to the Sylv'acctes and CREA Mont-Blanc associations.

In keeping with our environmental commitment to 2025, an important new feature was introduced this year: mandatory carbon offsetting for all runners.
Thanks to this collective measure, €40,000 has already been collected - a concrete step towards limiting the event's carbon footprint.
The organization chosen to receive the funds is theAssociation Française d'Agroforesterie (AFA) 👉 www.agroforesterie.fr
This organization works for the development of agroforestry: a practice that involves integrating trees into agricultural systems, with multiple environmental and climatic benefits. In addition to capturing atmospheric carbon, these systems promote crop diversification, soil preservation and farm resilience.
In addition, in order to limit the use of individual vehicles during the event, we have set up free shuttle systems , which on the one hand bring the 90km and 42km runners to their starting lines, and on the other hand offer companions the possibility of following the runners through the valley without using their personal vehicles.
Where it is not possible to use public transport, we strongly encourage runners, accompanying persons and members of the organization (volunteers, partners, members of the Club des Sports, etc.) to carpool. To do this, we promote the use of car-sharing platforms and put people in touch with each other who are offering or looking for car-sharing (by creating Facebook groups or WhatsApp communities, for example). Members of the organization also have access to a fleet of electric bikes, which they use whenever possible.
Finally, since 2021, we no longer use helicopters to produce aerial images of the event: these are now 100% produced by drones.
Preserving the Aiguilles Rouges Nature Reserve
4 races organized as part of the Mont-Blanc Marathon cross the Aiguilles Rouges Nature Reserve : the 90km, 42km, 23km and The Young Race.
Nature reserves are a tool for protecting natural environments. They protect areas, species, geological and/or biological heritage. Their main aim is to maintain or improve a state of conservation, but also to manage natural environments and raise awareness of their protection. We make our runners aware of the need to protect the environment, applying zero tolerance to littering and requiring them to stay on the trails. We also invite them to open their eyes to observe the remarkable animals, flowers and plants along the trails, and above all not to disturb the animals that have made their home in the reserve (ibex, chamois, wild boar, eagles, etc.)!
🍃 Best practices to adopt:
- Don't go off the trails
- Don't cut corners either on the way up or on the way down (this encourages erosion)
- Respect the race markers and permanent markers
- Don't use a drone
- Prefer to practice during the day, at night, disturbance is increased
- Get into the habit of putting your garbage in a pocket where it cannot escape
- When approaching a wild animal, slow down and let the animal move away at its own pace
- Know the correct behaviour to adopt in the presence of herd protection dogs
- Don't share your digital tracks, especially if they are false!
