Running and Environmental Impact: Are Runners Eco-Conscious?

Running likes to portray itself as a "clean" sport. No engine, no artificial turf, no heavy infrastructure—just you propelling yourself forward with your own muscle power. It's an appealing image. But when you scratch beneath the surface, running's environmental footprint is more complex than it appears. From the carbon impact of major events and the lifecycle of a pair of shoes to our paradoxes as runners who love nature, this topic deserves an honest discussion.

The Carbon Footprint of Races: The Travel Taboo

The Paris Marathon gathers around 50,000 runners. The New York City Marathon, also 50,000. The UTMB, 10,000 participants from all over the world. Behind these impressive numbers lies a reality rarely discussed: participant travel constitutes, by far, the largest source of CO₂ emissions for a running event.

Based on my research, a study conducted on a European marathon estimated that runner travel accounted for over 90% of the event's total carbon footprint. Cups, medals, logistics—all the things we usually criticize—are almost negligible compared to a transatlantic flight to run 26.2 miles.

This finding highlights an uncomfortable paradox: "race tourism," which encourages you to travel to collect race bibs, is probably the most polluting aspect of running. And it's also the most challenging to question, as it's so intertwined with the joy of discovery and the prestige of certain races.

Cups, Gels, and Waste: The Visible That Hides the Essential

Images of aid stations littered with crushed cups have become a symbol of "running pollution." And it's true that the waste generated by a mass event is significant: plastic cups, gel wrappers, bottles, bananas, sponges. Some major marathons generate several tons of waste in a single day.

Solutions are emerging: reusable or compostable cups, bulk aid stations, mandatory carry-your-own-cup policies for trail runners. The eco-cup has gained traction, even if it has its drawbacks (collection and washing logistics). But we need to keep perspective: this visible waste represents only a marginal fraction of running's total impact. Focusing exclusively on cups is a bit like meticulously sorting your recycling while flying every weekend.

Running Shoes: An Industrial Problem

This is probably the thorniest issue. A classic pair of running shoes accounts for approximately 14 kg of CO₂ to manufacture. It contains about ten different materials—EVA or TPU foams, rubber, nylon, polyester, adhesives—assembled in a way that makes separation for recycling almost impossible. And their average lifespan? Between 375 and 620 miles (600 and 1,000 km), or just a few months if you run regularly.

If you train seriously, you might go through three to five pairs a year. Multiply that by the millions of runners worldwide, and the number is staggering. The industry is aware: recycling programs exist (Nike Grind, adidas with Parley), but they remain marginal. The majority of worn-out shoes end up in landfills or incinerators.

Carbon plates, which have revolutionized performance since 2017, worsen the problem: they reduce shoe lifespan (often 185-250 miles or 300-400 km) while using materials that are even harder to recycle. Personally, the performance gain comes with an environmental cost that no one mentions at the finish lines.

Plogging and "Green" Races: Commendable but Limited Initiatives

Born in Sweden, plogging—a portmanteau of plocka upp (to pick up) and jogging—involves collecting trash during your run. It's a tangible, visible action that has the advantage of combining physical exercise with environmental action. Plogging communities have sprung up all over the world.

Similarly, "green" or "zero-waste" races are multiplying, with demanding specifications: aid stations without individual packaging, wooden medals, useful goodies instead of trinkets, carbon offsetting, and encouraged public transport. The Éco-Trail de Paris, for example, was a pioneer in this approach.

These initiatives are positive and deserve support. But we need to be realistic: they only solve a part—the most visible part—of the problem. Offsetting the carbon footprint of a Paris-to-New York flight for a marathon by picking up trash in a park is more symbolic than truly balancing the books.

The Nature Runner's Paradox

This is perhaps the deepest paradox of running and the environment. Trail runners, in particular, are often nature lovers. They run in mountains, forests, on wild trails. They have a visceral connection to the landscapes they traverse. Yet, their practice contributes to trail erosion, wildlife disturbance, and—when it involves long-distance travel—a significant carbon footprint.

Ultra-trails in sensitive natural areas (Alps, Pyrenees, national parks) are sparking increasing debate. Supporters highlight the economic benefits for mountain regions. Critics point to trail degradation, stress for wildlife, and the impact of temporary infrastructure. The truth, as often, lies in the nuance: it all depends on the number of participants, the season, the route, and the environmental management of the event.

Offsetting vs. Reduction: The Real Debate

Carbon offsetting—planting trees to "neutralize" emissions—has become the go-to for many race organizers. But the scientific community is increasingly critical of this approach. Trees take decades to sequester carbon, their survival isn't guaranteed, and offsetting does nothing to reduce actual emissions.

The hierarchy should be clear: reduce first, then offset. In practical terms, this means prioritizing races close to home, carpooling or taking the train, making your shoes last as long as possible, limiting impulsive purchases of technical apparel, and accepting that you can't run everywhere in the world without an impact.

This is a difficult message for a community that values adventure and discovery. But it's a necessary one. Why do we run? If it's for the joy of the act, the beauty of movement, meditation in action—then your run 3 miles from home offers all of that just as much as a marathon on the other side of the world. That's my opinion, anyway.

What Can Individual Runners Do?

Without excessive guilt or greenwashing, a few concrete actions can make a real impact: choose races accessible by public transport, limit "trophy" race bibs, maintain and extend the life of your shoes, buy used gear (the second-hand running market is booming), and support brands making verifiable efforts in sustainability.

And most importantly: don't forget that running remains, fundamentally, one of the least polluting sports out there. A runner who trains daily in their neighborhood, using a pair of shoes until they're worn out, has a negligible environmental impact compared to most other hobbies. Running has room for improvement, but it starts far ahead.