The Adidas Adizero Adios Boost 4 continues the tradition as one the most decorated distance racing shoes. The 6th version of the Adios and 4th with Boost features a welcome upper change with a similar sole design. The upper is a fantastic update that finally fixes the sizing issue and the forefoot fit. The sole remains the same with a design that works well (but I still prefer the extended forefoot torsion system of the originals).
Weight: 7.8 oz
Stack Height: 23 mm / 13mm
Drop: 10mm
Classification: Marathon/Distance Racer
FIT/UPPER
Finally, the Adidas Adizero Adios Boost 4 fits true to size. Unlike the previous versions, I did not have to size up to get adequate room in the forefoot. The toe box fits somewhat wider around the lateral toes but still give a snug racing fit. The midfoot fits similar to the previous versions with the laces able to snug the upper down well. The heel remains snug but the heel counter has slightly more padding between itself and the foot. It is not plush, but provides a little relief for those with sensitive heels.
RIDE/MIDSOLE
The Boost midsole in the Adidas Adizero Adios 4 provides a snappy and responsive ride. Like version 3, the forefoot is more flexible due to the removal of the extended forefoot torsion system. This provides a smooth toe off as the torsion system only extends into the anterior aspect of the midfoot. The toe spring has also been decreased, creating less pressure on the toes. This is something I have dislike about the last two versions of the Adios. The Adios 4 gets this right, which when combined with the flexibility creates a far smoother ride. Like previous versions, the midfoot midsole runs narrow in width and does not contact the ground. The heel remains the same as previous versions with extra carbon rubber on the outsole.
Although listed as only 0.1 oz lighter, the Adidas Adizero Adios 4 feels markedly lighter than version 3. This was apparent from the first few steps. Physically in my hand and on my feet. I do not have a scale to confirm this and is simply a personal observation. The Adios Boost 3 had more of a lightweight trainer feel to it while this again feels like a racing shoe (again finally).
STABILITY
The Adidas Adizero Adios Boost 4 is a neutral racing flat. It is not meant to be a stability shoe. Although the torsional rigidity creates some inherent stability, the narrow midfoot undoes that. A narrow platform means less stability. This is made up for somewhat by the slightly wider forefoot and decreased toe spring, but there are not a ton of extra stability features in the Adidas Adizero Adios 4.
That being said, the torsion system does extend back into the medial midsole of the heel. I have always noticed this and do feel that it provides somewhat of a post in the rearfoot. It is not extreme, but I believe it helps contribute to the stable feeling heel the Boosted Adios series needs. Especially with now little stability the midfoot provides.
SPEED
The Adidas Adizero Adios 4 is meant to go fast. This is a speedy shoe for almost any distance. I have used this shoe for kilometer repeats, 200m sprints and long steady state runs. It performs well on all of them. The thick Boost in the heel provides protection, bounce and speed over a variety of distances. The forefoot is far closer to the ground and is very fast due to the combination of boost, flexibility and good ground feel. This works well for short distances, but can be a bit bare bones over the marathon distance for some.
I would choose this shoe over a lighter shoe from 10k up to the marathon. Given the responsiveness and turnover, I would even consider this shoe for a 5k. Most runners will find this shoe peaks as a 5k to half marathon shoe. Some efficient runners will be able to tolerate this for a marathon and some will even be able to handle this for ultra marathons.
DURABILITY
As always, the Boost remains resilient long after the outsole will give way. The Adiwear and Continental Rubber on the outsole provide great durability and grip for a racing shoe. I expect the upper to last longer than the suede mesh of the previous versions (which would begin fraying quickly). Thus far I have not seen any seams loose. Many people will be able to get over 250 miles in this shoe. At this time I have 28 miles and see absolutely no wear.
THOUGHTS AS A DPT
I am still disappointed that Adidas took out the glorious extended forefoot torsion system found in the original unboosted Adios all the way to the Adidas Adizero Adios Boost 2. It increased the forefoot rigidity and provided an incredibly snappy feel like a track spike for the road. This was a bit too stiff in the unboosted Adios 2 (still one of my favorite racers) and for many people this could cause some issues in their forefoot due to the lack of flexibility. In the Adios 3, this was removed for a more flexible forefoot. This does create a smoother ride through increased flexibility, but made the shoe relax as a speedster. Some people liked this, others (me) didn't.
Whether people like this or don't comes down to individual biomechanics and muscle tuning. Increased forefoot stiffness requires more power from the calves to propel the body over a stiff forefoot. Normally this is made more efficient through the extension of the toes (aka the forefoot rocker). In previous versions, the extensive toe spring is what made up for this lack of flexibility. The more toe spring there is, the less the calves have to propel you forward because you are already rolling forward. For those that have no mobility left in their toes, especially the great toe (which is especially common with age if you don't work on your mobility), this works great to continue running.
The decreased stiffness in the forefoot will allow some people to enjoy this shoe while it may push others away. I would love to see a return of the extended forefoot torsion system (as it was also removed from the Takumi Sen series), but understand that most people aren't used to shoes that aggressive. However, with the general acceptance and widely loved Vaporfly 4% having a full length carbon fiber plate, I don't see why Adidas can't create a stiff, fast, yet comfortable ride.
WHO THIS SHOE IS FOR (Conclusion)
The Adidas Adizero Adios Boost 4 is a long distance racer that will work for those looking for a traditional, neutral and fast ride. The heel drop and Boost cushioning in the rearfoot will keep legs fresh over long distances. The low forefoot is fast over the shorter distances and may not be enough for some over the marathon. The upper is a welcome change with consistent sizing and a bit more room laterally while the sole remains the same from the previous version. This is a racer that works and does so for many people. Adidas wins this game with consistency (but I am still looking forward to seeing an updated sole in version 5).
GRADING
Fit/Upper 9/10
Ride/Midsole 8/10
Stability 6/10
Speed 9/10
Durability 9/10
Total Score: 84%
Thanks for reading!
Editor's Note: As always, the views presented on this website belong to myself or the selected few who contribute to these posts. This website should not and does not serve as a replacement for seeking medical care. If you are currently injured or concerned about an injury, please see your local running physical therapist. If you are in the Los Angeles area, I am currently taking clients for running evaluations.
Dr. Matthew Klein, PT DPT OCS
Doctor of Physical Therapy
Board Certified Orthopedic Clinical Specialist
Kaiser SoCal Manual Therapy and Sport Fellow
Doctor of Physical Therapy
Board Certified Orthopedic Clinical Specialist
Kaiser SoCal Manual Therapy and Sport Fellow
***Disclaimer: These shoes were purchased for there full US retail price. This in no way affected the honesty of this review. We put at least 50-75 miles on trainers and 10-25 miles on racing flats prior to reviewing them. Currently I have 28 miles on my pair. My views are based on my extensive history in the footwear industry and years testing and developing footwear. If you are a footwear rep looking for footwear reviews or consultations on development, we are currently looking to partner with companies to assist, discuss and promote footwear models. Partnership will not affect the honesty of our reviews.
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