When conversations turn to sustainability in footwear, they usually head in one of two directions: new materials or recycling programs. Both sound promising. Both make for good headlines. And both, on their own, miss the largest source of waste in the system.
The real problem in footwear is not what shoes are made of.
It’s how many usable shoes never get used.
Footwear waste is overwhelmingly a utilization problem.
Where Footwear Waste Actually Happens
A running shoe accumulates most of its environmental cost before it ever reaches a runner. Raw materials are extracted. Components are manufactured. Shoes are assembled, boxed, shipped—often across multiple continents—and distributed through retail networks.
According to lifecycle analyses conducted by MIT and Quantis, the majority of a shoe’s carbon footprint is created during production, not during use. That means the environmental impact is largely “paid upfront.”
When a shoe is worn for hundreds of miles, that impact is amortized over meaningful use. When a shoe is never worn—or worn only briefly—the footprint remains, but the benefit disappears.
This is where the system breaks down.
Returns, excess inventory, and forecasting errors create a massive pool of footwear that is structurally sound, functionally intact, and environmentally expensive—yet at risk of being wasted.
Why Recycling Alone Can’t Fix This
Recycling footwear is notoriously difficult. Shoes are made of layered materials bonded together with adhesives that are not designed for separation. While some recycling initiatives exist, they are limited in scale and often downcycle materials into lower-value uses.
Even in best-case scenarios, recycling happens after a product’s useful life. It does nothing to address the waste created when shoes are discarded before that life ever begins.
From a sustainability standpoint, this is backwards.
The highest-impact intervention is always extending product use. This principle is widely supported by organizations like the Ellen MacArthur Foundation and the World Resources Institute, which consistently rank reuse and redistribution above recycling in waste-reduction hierarchies.
In simple terms:
A shoe that gets worn is more sustainable than a shoe that gets recycled.
The Hidden Cost of Unworn Shoes
Unworn footwear represents one of the most inefficient outcomes in retail. The resources have been spent. The emissions have occurred. The labor has been invested. But the shoe delivers no utility.
Returned shoes—especially those that were tried on indoors and never run in—are a perfect example. They are not defective. They are not worn out. They simply didn’t find the right match the first time.
Historically, retail systems haven’t handled this well.
To protect brand pricing and avoid channel conflict, many shoes are:
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Liquidated through opaque channels
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Donated without accountability
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Or quietly destroyed
Public disclosures from major fashion and footwear brands over the last decade have shown that destruction of unsold inventory is not rare—it’s structural.
The waste here isn’t accidental.
It’s systemic.
Why Secondary Markets Change the Equation
Secondary markets exist to correct this inefficiency.
When unworn and lightly handled shoes are redirected to runners who will actually use them, the environmental math changes immediately. The same shoe now delivers real performance, real mileage, and real value—without requiring new production.
This is where Relay operates.
Relay’s role is not to recycle shoes or rebrand waste as virtue. It’s to keep functional footwear in use by providing a brand-safe, transparent path from excess inventory to real runners.
That distinction matters.
Resale works best when it preserves value, not when it treats products as damaged goods. A shoe that didn’t fit one person isn’t a failure—it’s unfinished.
Why “Use the Shoes” Is the Most Practical Solution
The simplest sustainability solution is often the least flashy: make sure products are actually used.
Extending the life of a shoe—even by a single owner—reduces the demand for new production, lowers per-use environmental impact, and prevents unnecessary disposal. When scaled across millions of pairs, the impact is significant.
According to the EPA’s Sustainable Materials Management framework, source reduction and reuse provide far greater environmental benefits than recycling or disposal alternatives.
In footwear, that means:
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Selling existing inventory before making more
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Matching shoes to runners who need them
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Treating excess as a distribution problem, not a waste problem
Relay’s second-try model is built on exactly this logic.
Waste Reduction Without Compromise
One of the most important aspects of this approach is that it doesn’t ask shoppers to compromise.
Runners don’t need to accept lower performance.
Brands don’t need to erode their integrity.
Retailers don’t need to destroy value.
When systems are built correctly, waste reduction becomes a byproduct of efficiency—not a moral burden placed on consumers.
The shoe gets worn.
The runner gets performance.
The system wastes less.
That is not a tradeoff.
That is alignment.
Sources Referenced
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MIT Life Cycle Assessment Lab
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Quantis Footwear Lifecycle Studies
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EPA Sustainable Materials Management Framework
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Ellen MacArthur Foundation Circular Economy Reports
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World Resources Institute Waste Reduction Hierarchy