Compostable running flat

Starting a new side project around the idea of a compostable long distance running flat and experimenting with an open-style process, posting work as I go instead of waiting for a nice render at the end.

The idea is that compostable materials, especially foams, will lag behind non-environmentally friendly materials for the foreseeable future. Serious runners are hesitant to risk their health (putting hundreds of miles into less than perfect training shoes) or their success (toeing the line in less than the absolute best the industry has to offer [see Vaporfly sponsorship controversy]), but a lightweight training flat used in tempos, interval and speed sessions, is a category with significantly lower risk, mileage, and expectations of durability. I think at the right price point, this could be a great entry into “green” footwear for a lot of runners.

I’m thinking of using a previous project as aesthetic inspiration but hoping to push it into being a bit more commercial and manufacturable. As far as performance features, I’m hoping to eek out the best performance possible from the materials through a combination of EVA and strategically placed PU (Salomon has used this technique in some of their trail shoes), maybe some mechanical cushioning like OnCloud uses, as well as some midsole geometry tricks like what NB has been doing with the lateral side swell for forefoot strikers, but this is where I could really use your help. There are so many tricks when it comes to strobel materials, specific foam layering, gluing or not gluing layers, midsole shaping, etc. that could really impact the overall experience and shrink the gap to the ZoomX or LightStrike-based flats of the world.

I’ll be posting sketches and any other process work here and hoping to be incorporating any and all feedback into the process on a deep level. I’ll also be posting on my IG (@joshythorson) if you’d rather follow along there.

Thanks for reading! Here are the first round of sketches, any first impressions or ideas about running footwear, compost ability, or the process?

have you ever checked out the Nike Mayfly?

Definitely! My brother actually ran a few races in a pair, then ended up using a few more pairs as kick around shoes.

The first biodegradable footwear project I did was actually inspired by the Mayfly’s but thinking about what comes after they “die.”

I was thinking a bit about the idea of limited lifespan like the Mayfly’s, but more out of material limitations and less about saving weight, probably a bit of the same simplicity will be needed

After a few conversations with distance runners, there were several hints that a trail shoe might be an appropriate foray into compostable training footwear for runners, albeit a smaller slice of the overall running market. Will mull/sketch over some of those ideas in the coming days.

Prior to those insights, I did this little study of all of the top race footwear meant for road marathons that I could find. Some interesting consistencies in the forefoot across brands, more variation in the heel.

For more accuracy, I blacked out all designs and overlaid at a consistent opacity.

Just the midsoles.

I feel like there is a resurgent interest in trail.

As a runner and running shoe designer…

  1. I get the interest in compostable materials, but I don’t think I follow how it is part of your design. Is the material integral to the construction? Is it supposed to be disassembled after? Is this is a real material or something magic that doesn’t exist? Why compostable instead of recyclable? Adidas has a fully plastic shoe (laces, materials, thread, glues, etc.) that is supposedly fully end to end recyclable.

  2. If you are considering performance vs. environmental concerns, I’d think a tempo shoe or any other higher performance racer, is not the way to go. If you are actually training and racing, I think going fast is more important than anything. That being said, the lifecycle does get shorter. I replace my shoes almost every month after about 400km on them. Maybe something like trail where there is more an environmental vibe and pure speed performance isn’t as important makes sense. Or a more general training running shoe. Or recovery. Or component based design…

  3. I wouldn’t take anything from comparing photos of shoes. There’s too much variability on angles to mean anything on actual last shape or fit or geometry.

  4. I’d agree the mayfly direction is interesting. Made to be disposable could be a good angle if the magic material still functioned. I think they were meant to go 100km? Which is still pretty far. Maybe a one race shoe, and something for middle distance like 5000m? 10k?

  5. Link to previous project doesn’t work


  1. Sorry I didn’t make that clearer, compostable performance EVAs and PUs exist and perform well, just not as well as the top of line EVAs/PUs/Pebax of the world. The idea is to choose a use-case where a slight hit in performance is acceptable for distance runners (i.e. non-race and non-high injury risk situations, such as high-mileage traienrs). I definitely admire what Adidas has done with the Adidas Loop concept, and while I was at VF Innovation we did a deep dive on circularity and consumers returning products. From that research I wasn’t sold that consumers would consistently return shoes (in 2020 anyway, in a decade or two who knows). Also since only around 9% of plastic actually gets recycled, so it doesn’t seem like a good long term solution. I think staying away from materials that don’t decompose is the best short term solution until we create better take-back programs that consumers understand and habitually participate in.

tl;dr the shoe could be directly buried after use, no disassembly or prep required. All materials decompose into inert/non-bioreactive/non-toxic materials. Use clever construction methods and techniques such as mechanical cushioning, plates, etc. to eek out extra performance of slightly sub-par foams.

  1. Right now I’m working on two concepts (which I’ll post some more sketches of in a bit), where one is trail based and the other is a lightweight trainer. Admittedly, neither of these has a large market but for this project I’m fine with that. When I say lightweight trainer, I mean the type of shoe you only pull out for workouts, potentially only putting 50-100 miles a season into them. My brother was a fan of DS Trainers, I’ve used Adidas Adios for a while, you’ve got Brooks Launch, Pegasus Turbos, Saucony Kinvaras, etc. So these are meant to be fast, but if they aren’t Alphafly fast that’s fine because you’re training, not racing, and they still will perform well, just not absolute peak performance. I also avoided the idea of regular trainers because as someone who’s teetered on the edge of injury for most of my career, I wouldn’t take a risk on a bio-based shoe for the shoe I’m spending 300 miles a month in. I totally agree that these wouldn’t be for everyone (and from the interviews I’ve done there’s been a bit of hesitancy) but part of the core part of the project is to start proving to serious distance runners that green foams can get the job done, and if there are any trade-offs they are minimal and worth it.

I agree that the trail version is the best story and probably best use-case, the second is more for fun and to show how the design language could change per use-case as well.

  1. I agree and disagree, these are all almost isometric side views, with the image sizes controlled for by stick length so there is some consistency (enough for a 50,000 ft view at least). I won’t be taking anything concrete from those images, but I do think it’s interesting that the forefoot radii (toe-springs) are very nearly the same across brands.

  2. Thanks, that’s the second part of the story I’d like to explore. Like I said, while I agree that circularity and take-back/recycling programs will take off in the future, I think composting is a superior short term solution that is less likely to be screwed up by the consumer or recycling process(recycling a shoe can go wrong at many different steps in the process, composting is pretty dead simple and occurs regardless of location). I also believe in the future all of our disposable and semi-disposable products will be compostable, but that’s a whole different topic.

  3. Thanks for the heads up, Adobe subscription lapsed since I graduated. Hopefully can recover the site, otherwise will rebuild.

Pictures from that project, more concept than anything else.