Disclosure: The Adizero x Allbirds running shoes was purchased with our own money.
Daily Running Co Sustainability Project
This review is part of Daily Running Co’s Sustainability Project where we run in pairs of shoes targeted to reduce our impact on the environment. As part of the Project, we want to assess and determine the experience, feasibility, and learnings from threading lighter as a user. At the end of the project, we will publish a report on our findings.
Introduction
Adidas and Allbirds, two high profile companies in sustainability came together to drive the development of sustainable running shoes. While they are competitors, both companies see benefits to collaborate on a revolutionary project. Adidas a leader in the footwear industry with well-established performance and processes for traditional running shoes coupled with the expertise of Allbirds in sustainability.

In this project, the aim throughout the design and manufacturing processes was to keep the CO2e footprint to a minimum. The version 6 has a CO2 emission at 2.94kg. This is about 21% of a traditional pair of running shoes (Cheah et al, 2013).
Runner’s Profile
Prior to the review, it is important to establish my runner profile to better gauge my opinions on the shoes. For example, a lighter runner will experience differently the effects of midsole compared to a heavier runner. I am on the heavy side for a runner (75kg – 80kg) range and stands at 1.75m tall. My average weekly mileage ranges from 25km to 35km. I am a mid-foot/fore-foot strike with a neutral foot. I am normally a US size 11 although it varies depending on brands.
First Impression Review
Let us kick off the review with some specifications of the shoes. Based on Adidas’s webpage, the shoes feature a bio-based EVA midsole made with 17% plant-based material derived from sugarcane. Allbirds’ EVA midsole is known as SweetFoam, the world’s first carbon negative green EVA, which derives from parts of sugarcane. The SweetFoam is like the midsole used in the build up of this pair of running shoes. The remaining 83% has been made known that it is Adidas’ trusty Lightstrike midsole foam. The marketed weight of the shoes is 153 grams.

Here are the statistics of my UK 11 Adizero x Allbirds 2.94 KG collaboration shoes, honestly is there any name for this collaboration?
- Weight: 186 grams (6.5 oz)
- Forefoot Stack Height: 14mm (excluding the sidewalls)
- Heel Stack Height: 24mm (excluding the sidewalls)
- Insole thickness: ~ 3mm
- Outsole rubber thickness: 1mm & 2mm in different areas.
I took the Adizero x Allbirds out for a 10 km first impression run coupled with a few causal days’ usage. Not only have I gotten looks on my pair of shoes which look very eye-catching but also questions about what that is. Common questions I have gotten is certainly what model is it, the brands are printed on it, so it is easy to identify. Other questions are is it comfortable and will it degrade prematurely among others. A key shocker was when I mentioned that it is a pair of running shoes. “It does not look like one”, is a common reaction
Five Main Pointers
Point 1 – Fits My Wide Feet Well
There was no concern about how my wide feet felt within the shoes. The widest part of the shoe measures 14mm, the narrowest comes in at 7mm while the heel measures 8mm wide. From the design and statistics of the shoes, it is very similar to the Adizero platform used in Adizero Pro.
Point 2 – Worried About Secured Fit with a Minimum Upper
With the approach to minimize the overall carbon footprint of the running shoes, there are some compromises to be made in terms of materials. The upper is designed to be very minimal with reinforcement built in using threads and provide some level of structure. Flimsy upper is one word to describe the visual impression. However, flimsy it certainly is not. Not only can it provide a good, secured lockdown over the midfoot, but the softness of the materials also helps with my wide foot.
That said, one concern I have is regarding the heel lockdown. While there are pieces of cushion which act as comfort points and perhaps lockdown, there are barely anything else. However, due to the lightness of the shoes, there is hardly any slippage in the heel area during runs.
Point 3 – Resilient Midsole Cushioning Despite Low Stack Height
Despite the midsole coming in at only 14mm underfoot, it certainly did not feel so. The midsole provided ample cushioning as I ran in them. The cushioning is not the super soft and bouncy type you get in the Fuelcell or Lightstrike Pro. Yet, it made an impression that it is resilient to me during my run. It is a very welcoming and accommodating midsole.
Point 4 – Thin Laces, a Concern?
The company had the laces kept to a minimum and reduce material usage. Thin, flat, but stretchy laces came together with the pair of shoes. While the laces had yet to bring me any issues thus far, I cannot help but wonder if it will last over time. A secure lockdown in the midfoot area is crucial for me in any running shoes. Thus far, it has not been an issues during my runs.
Point 5 – Minimum Outsole Rubber, Unknown Durability
The durability of the outsole is my concern given that some sections of it only has a 1mm rubber thickness. In the lateral heel and the medial forefoot, the thickness increased to 2mm. While the reduction in thickness of rubber material will help with the carbon emission during production, it also begets the question about overall durability and usability of the shoes. If the running shoes is unable to hold up itself in the outsole over time, it could shorten the lifespan and the need for another pair.
What’s Next?
The important question remains to be answered as we take the pair of running shoes to 100KM or more: the durability. It is important for us to review the performance and the durability of the running shoes. Both help us to formulate our view on the feasibility of going more sustainable.
We hope you have found our initial review of the Adidas x Allbirds collaboration informative and useful. Do share with your running friends and community if this has been helpful for you or anyone who might benefit from our work!
Do keep a lookout as we cover other brands who have practices and products aiming to reduce our carbon footprint. Remember to check out our short clip for a first look at the Adidas x Allbirds collaboration below.