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Tuesday, June 22, 2021

Adidas Adizero Boston 10 Review (2021 Release)

Adidas Boston 10, white original colorway in hand. Black stripes seen, and topsole of Lightstrike Pro. Red external heel collar.
Adidas Adizero Boston 10 Review
By Chief Founder Matt Klein and Senior Contributor Nathan Brown

The Adidas Adizero Boston series has a long history as a lightweight trainer and marathon racer. Despite Adidas's extensive racing flat history, the Boston was a common choice for those looking to go fast and long in training and racing. Even among elite athletes it was a common choice for those who thought the Adios wasn't enough. While changes were made with upper materials and Boost additions, the spirit has remained similar through the generations. The Adidas Boston 10 is a dramatic change from previous designs, featuring a maximalist design, rods in the midsole and Lightstrike/Lightstrike Pro combination. How this design affects the ride of this long time lightweight trainer is interesting....


Adidas Adizero Boston 10
Price: $139.95 per Running Warehouse

Weight: 10.4 oz / 295 g (men's size 9) 9.4 oz / 266 g (women's size 8)
Sample Measured Weight Men's size 10 US: 10.8 oz
Stack Height: 39 mm / 31 mm 
Drop: 8 mm
Classification: Max Cushion Daily / Uptempo Trainer


ADIDAS BOSTON 10 SUMMARY


The Adidas Adizero Boston 10 is a maximalist uptempo trainer that returns as a different shoe that can still move. A huge midsole with a 39mm heel stack height features Lightstrike, Lightstrike Pro and rods in the midfoot to forefoot provide two different rides. At easier paces, the shoe is a stable firmer riding trainer than can handle decent mileage. At faster paces, the shoe turns over faster than expected for a 10.4 oz shoe. A new upper with a slightly snug forefoot and a more open heel create some slight lockdown issues, but lace locking mostly fixes this. Best for daily training, uptempo long runs, tempo runs and intervals, the Boston 10 loses its racing edge but should work for a larger variety of people.


BOSTON 10 FIT

Matt: The Adidas Adizero Boston 10 fits me true to size in my normal men's US size 10. The toe box does taper with the suede, which does open up with time. The fit is more performance oriented in the forefoot and opens in the midfoot and heel. The heel is a bit wider, which resulted in some heel slippage. This required me to lack lock the shoe and although this helped, the laces were almost too short to accomplish this. There is a flexible heel counter in the rearfoot, but there is enough padding around the collar that I did not notice. The tongue is gusseted and stays in place well. It is an extension of the duel layer upper. A mesh layer sits underneath a more plastic type mesh. This can make the upper a little warm. Tightening the laces does help lock the foot down more, but this does cause a noticeable increase in pressure across the top of the foot. Sockless running is not advisable due to extensive internal mesh and stitching. The upper overall wells like half daily trainer and half lightweight trainer which matches the personality of this shoe.

Nathan: So far I've tried two Adidas shoes, and I'm quickly learning they have a somewhat unique fit. Although this shoe is true to size, there is a slightly more snug, performance-like toe box with a notable taper. Early on this seemed to encroach on my toes slightly, but did improve and open up over the first 15-20 miles. The guesseted tongue is also one of the more snug that I've experienced. Without the laces, the shoe is actually held in place quite well. This is good because I had trouble lacing this shoe to my comfort given the thin tongue combined with stiff, thin, and short laces. Eventually I figured it out, but the shorter laces did not leave room for much lacing variability (obviously an easy fix...you can just put your own laces in there). The laces did push into the dorsum of my midfoot if I really tried to lock it down, but once the upper settled in, I had less issues. There is a thin padded "block" at the top of the tongue, which is nice for lacing down tighter without putting pressure over the top of the foot.

Okay, enough about lacing. The upper is somewhat rigid with the combination of the plastic-like mesh layer and some suede-like overlays The thiner mesh is nice and breathable, where the suede provides structure and stability to the upper. There's a light identity crisis about if this upper is supposed to be performance or trainer, but I found that once it loosened up it was great for daily miles. 



PERFORMANCE

Matt: The ride of the Boston 10 features a firmer heel with a slightly more bouncy forefoot. The ride is well rockered, with a significant posterior lateral heel bevel in the rear. The slightly wider midfoot provides a nice transition into a stiffer forefoot. At slower paces, the forefoot can be a bit stiff. However during workouts, uptempo and normal paces the toe spring, extra Lightstrike foam Pro and rods in the midfoot to forefoot make it easy to get up on your toes. As the shoe breaks in, the forefoot becomes slightly more flexible, so it is not as abrupt as the Adios Pro. I currently have over 100 miles on my pair and the shoe continues to get better the more it breaks in. Initially the shoe is stiff, but as it becomes a bit more flexible and smooth. The outsole is starting to wear though and although there is extra cushioning, I am chewing into the midsole. 



The heel is firmer with more Lightstrike and the forefoot is slightly softer (but still firm) and bounces a bit more. The ride overall is more performance oriented and feels a little lighter than its 10.4 oz weight. However, as you fatigue this weight begins to be more noticeable. This is a significant increase from the previous version (over 2 oz) and while Boston 10 works well for tempo runs, it starts to feel a little bulky going any faster than that. For uptempo runs, daily training and long runs, the extra cushioning is protective and works well. This makes the Boston 10 more of a daily trainer than a racing shoe, although it can still pick up the pace. 

Nathan: Let's get two things out of the way. 1. This is one of the most firm shoes that I've tested this year. and 2. It's also my current go-to trainer. There is a dual density midsole. The lower layer, and bulk of the shoe, is Lightstrike EVA. If you haven't ran in Lightsrike before, it's a very firm compound. It doesn't give pop or bounce, or really any soft sensation, it's just kinda "there". A benefit of this is that it really allows the geometric shaping to do it's work. For those who want a soft shoe, this isn't it. But for those who like firmer shoes, like myself and Matt, the Lightstrike provides a platform that, again, allows the shaping of the shoe to do it's work (more on that later). The top layer is Lightstrike PRO, the compound found in the Adios Pro 2. To be honest, I don't really feel the Lightsrike PRO much unless I'm really pushing the pace. The rearfoot Lightstrike PRO seems more like a rim around the heel more than a full thickness slab under the heel. Part of that sensation is likely because there is a carbon heel plate that sits right under the stitching in the shoe. It's darn hard and firm, so if you have issues with heel soreness that could be a consideration as something to try before purchacing. The Lightstrike PRO in the forefoot feels more present and seems thicker and gives a bit of pop when picking up the pace. Sandwhitched between those two foams are the Energy Rods, which are made of a plastic material. These rods were very stiff initially, but became more flexible by 15 miles. When all was said and done, this shoe rolled along really well. The geometry works really well with the lateral bevel in the heel, full contact outsole, and then the mild toe spring that is integrated into the midsole. As I said above, a firmer foam will allow the geometry to do it's job, and this is a very well designed shoe in terms of rockers. It is not extreme where it feels like it is throwing you forward and provides transitions without any hiccups. The more mild toe spring combined with the slightly flexible rods ends up producing a relatively natural feeling toe-off. The shoe probably most akin to this in terms of ride is the Saucony Endorphin Shift, but the Boston has a bit more speed capability. 


(Matt's Adidas Boston 10 outsole after 100 miles)
 
Nathan's pair after 200 miles


STABILITY 

Matt: The Adidas Adizero Boston 10 is a neutral shoe, but feels like a mild stability shoe. The heel has a significant posterior lateral bevel, which almost acts like a wedge. This makes heel lands very stable for those who pronate, but may be a little unstable for those who supinate. The rods in the midfoot and forefoot stabilize both areas and prevent any torsion. This rigidity adds stability and forward motion is facilitated by the significant toe spring. The toe off feels guided with the spring and rods, however the rides can be a bit stiff at first. The midfoot does not narrow like other shoes and feels stable. This is also due to the elevated Lightstrike Pro midsole around the foot that acts like a cradle. There is a cut out in the outsole/midsole that still features a filled in medial midfoot. This seems to create some contrast as the foot will stay in the middle (ie the pocket). Overall the ride is very stable without using any traditional stability elements and almost reminds me of the Adizero Tempo series. This is particularly noticeable as the forefoot, with its wider last and significant toe spring providing a decent amount of natural stability up front. Those sensitive to stiffness and lateral bias in the rearfoot should be cautious, but those looking for mild stability will enjoy this shoe. 

Nathan: I agree with Matt above. The firmer foam, wide platform, and geometry/Lightstrike PRO "cradle" provide quite a stable ride for a neutral shoe. Clearly the higher stack will introduce a bit of instability, but nothing significant and people who typically like mild stability may do well in this shoe (similar to in the Endorphin Shift).




THOUGHTS AS A DPT / FOOTWEAR SCIENCE

Shoe development has progressed a great deal in the last several years. Even what we understand of stability has changed. The Adidas Adizero Boston 10 to me feels like an interesting mix of the retired Adizero Tempo series and the Adizero Boston series. The Boston was previously a lightweight trainer/marathon racer that was fairly neutral, whereas the Tempo was also a lightweight trainer and worked as a marathon racer for many, but had some mild stability. The recent Tempos had more forefoot stability through mild firmer use of Boost or posts on the medial forefoot. This was not always the case, but the shoe evolved. The current Boston 10 does not have any second density foam, but has several methods mentioned previously that strongly remind me of the Tempo. This is a reminder that stability can be created through many ways outside of posts/second density foams or wedges.

The energy rods in the midfoot and forefoot do a great job of creating rigidity in both areas. The shoe is particularly stable in the forefoot as the last is wide, the rods resist any torsion and there is a significant and aggressive toe spring. These components help guide the foot forward and create a rigid platform for those who need it. People need to be cautious however as different amounts of stiffness will work for different people (Mcleod et al., 2020). So the level of stiffness in the front may or may not work for you. The heel bevel used in the rearfoot is quite strategic. Most people land on the lateral aspect of their foot regardless of where they land (heel, midfoot, forefoot). The majority of people are heel strikers (Hasegawa et al., 2007; Larson et al., 2011) and are more likely to land on the posterior lateral side. This is why I usually suggest a slightly lateral heel bevel. The one used in the Adizero Boston 10 is significant, which if large enough will act like a medial wedge. This essentially means the medial side of the shoe is higher than the lateral side, so motion will be biased toward the lateral side. The foot will generally move in the path of least resistance, thus this can provide a significant amount of guidance.

Again, the Adidas Adizero Boston 10 is not a stability shoe, but shows off many current day examples of stability that provide structure to a shoe without being invasive. Thus it seems to traverse the line of neutral/mild stability shoe. Each person will react different to the shoe, so you have to take your own personal biomechanics and preferences into account first.

References

Hasegawa, H., Yamauchi, T., & Kraemer, W. J. (2007). Foot strike patterns of runners at the 15-km point during an elite-level half marathon. 
Journal of strength and conditioning research21(3), 888.

Larson, P., Higgins, E., Kaminski, J., Decker, T., Preble, J., Lyons, D., ... & Normile, A. (2011). Foot strike patterns of recreational and sub-elite runners in a long-distance road race. 
Journal of sports sciences29(15), 1665-1673.

McLeod, A. R., Bruening, D., Johnson, A. W., Ward, J., & Hunter, I. (2020). Improving running economy through altered shoe bending stiffness across speeds. 
Footwear Science12(2), 79-89.





RECOMMENDATIONS

Matt: The first suggestions I have pertains to the upper. The heel is a bit loose, so I would suggest extending the laces and/or thickening up the cushioning in the heel to reduce space. The suede in the forefoot looks cool, but initially tends to narrow the toe box more than necessary. I personally would prefer an upper similar to the original Adios Pro, which may even save some weight. The current one is far heavier than necessary and if lightened could reduce weight. This is more of a training shoe though, so durability may need to be the bigger focus.

The other point is that the Boston 10 has gained an incredible amount of weight. This increase makes me confused as to the point of the Adidas Solar series. There is a ton of midsole here, which can probably be slightly reduced in order to lighten the ride and differentiate its function. The Lightstrike Pro is a great, but there may not need to be as much Lightstrike. Again this will depend on the true purpose of the shoe and even at over 10 ounces it moves quite well.

Nathan: I agree with Matt above about changing some of the fit for the lacing system was difficult to secure the foot very easily and the toe box was tapered just a bit too much. I think my biggest recommendation, though, would be to lower the plate in the heel to allow for a slightly softer landing. It's just too close to the surface and over long miles I did notice the firmness (offset a bit by the nice bevel).

WHO THE ADIDAS BOSTON 10 IS FOR


Matt: 
The Adidas Adizero Boston 10 is a maximalist trainer/workout shoe featuring some fast components similar to its elite siblings. At over two ounces heavier than previous, this is more a training shoe now that is surprisingly stable. The upper has a more traditional tapered forefoot with a bit more room as you move to the back of the shoe. While it can make it down to tempo paces, it is best as a daily trainer and uptempo long run shoe. The Boston will serve as a great transition into maximalist racing shoes like the Adios Pro or for those wanting a maximalist ride in a trainer. 

Nathan: The Adidas Adizero Boston 10 is a whole new take on the Boston. It's enters the maximal trainer category, and is geared towards runners who want a truly firm ride that feel very consistent over long miles and protective despite the firmness. It not only provides very smooth transitions, but it's wider platform and geometry provides a naturally stable ride.


BOSTON 10 GRADING

Matt
Fit: (Slightly more performance fit with a thick upper, slightly narrow toe box and a loose heel. Will require lace locking) 
Performance: B+ (More trainer than racer now. Maximal stack height works for training although ride through forefoot is a bit stiff until the shoe breaks in. Can still pick the pace up, but peaks at tempo pace) 
Stability: A- (High level of stability for a neutral shoe, lateral bias at heel with lateral bevel, very stable forefoot.) 
DPT/Footwear Science: B+ (Rods in mid/forefoot provide stability in that area. Strategic use of bevel creates laterally biased stability at heel. Filled in medial midfoot and the fact that the midfoot last does not narrow creates high level of inherent stability. Rods in an already maximal shoe however can make the shoe a little stiff, so that toe spring needs to perfected) 
Personal:  A- (This shoe works very well with my mechanics. Despite the mild lacing issues, I have continued to reach for this shoe for everything. Workouts, daily runs, long runs. This shoe can do it all, just not racing) 
Overall: B+ (A big change for the Boston series. Maximalist ride that is more a trainer now but can still move at tempo paces. Good way to ease into wearing more aggressive maximalist racing shoes. Upper needs a little tweaking however to streamline fit. Those wanting a stiffer and more naturally stable ride will enjoy this shoe. )   

Nathan
Fit: B- (Taper in the toe box a bit sharp, lacing issues made it hard to get secure lock down without irritation) 
Performance: B+ (A LOT of preference will go into how you think this thing performs, steady trainer with really smooth geometry, very firm) 
Stability: A- (For a neutral shoe wit higher stack, very stable with the firmer foam and wider base) 
Personal:  A- (This is my current go to trainer for most daily runs and longer runs, only issue for me in the fit) 
Overall: B      

VIDEO REVIEW OF THE ADIDAS BOSTON 10 WITH COMPARISONS

 

Contributor Nathan Brown checks in with his thoughts on the Adidas Boston 10 and some comparisons with this year's favorite shoes.

SHOP | SUPPORT DOR

Adidas Adizero Boston 10
Price: $139.95 per Running Warehouse


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FURTHER READING

Compare Unique Daily Trainer Options
Saucony Endorphin Shift 2 -
High stack, rockered (speedroll) Saucony offering that also lends to big mileage
Nike Pegasus 38 - Airpods help give a bouncy ride on top of durable react foam
Hoka Mach 4 - The premium daily trainer of 2021
Saucony Endorphin Speed 2 - A comparative uptempo trainer in terms of technology

Recently at Doctors of Running
Mizuno Wave Rider 25 Review - The Rider reaches a landmark year, now featuring soft full length Enerzy foam for a next generation ride
Coros Apex 46mm Review - David Salas checks in on the Coros Apex which he's used extensively for track and trail running these past few months
Asics Kayano 28 Review - The long running Kayano gets a soft Flytefoam Blast midsole to shake things up
Puma Eternity Nitro Review - Puma's new mild stability trainer in the Niro series

Thanks for reading!

TESTER PROFILES:

Dr. Matthew Klein is a 150 lb male with notable PRs of 14:45 for 5k and 2:32:44 for the full marathon.  He typically runs 70-100 miles per week and trains at a variety of paces from 8min per mile recovery runs to 4:40 per mile 1k repeats.  He prefers firmer and responsive shoes with snug heels and medium to wide toe boxes.  The stability guy of the group, he also prefers a little stability in his footwear. However, as a researcher, clinician and running shoe aficionado, he will run in anything. IG handle @kleinrunsdpt

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.

***Disclaimer: These shoes were provided free of charge in exchange for a review.  We thank the people at Adidas US and Running Warehouse for sending us pairs.  This in no way affected the honesty of this review. We systematically put each type of shoe through certain runs prior to review. For trainers and performance trainers, we take them on daily runs, workouts, recovery runs and a long run prior to review (often accumulating anywhere from 20-50 miles in the process). For racing flats we ensure that we have completed intervals, a tempo or steady state run run as well as a warm up and cool down in each pair prior to review. This systematic process is to ensure that we have experience with each shoe in a large variety of conditions to provide expansive and thorough reviews for the public and for companies. Our views are based on our 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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