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Saturday, December 31, 2022

Adidas Adizero SL Review (2023)


Adidas Adizero SL Review: The Adidas Daily Trainer You Were Looking For
By David Salas, Matthew Klein, and Nathan Brown

The Adidas Adizero line has always been geared toward performance. The SL continues upon this tradition, but extends the Adizero liveliness into a daily trainer. The Adidas Adizero SL is a daily trainer that uses a full bed of both Lightstrike and Lightstrike Pro to provide a daily trainer that has a little extra pop through the forefoot and toe off. 

Price: $119.95 at Running Warehouse
Weight: 8.5 oz, 241 g (men's size 9), 7.6 oz, 215 g  (women's size 8)
Stack Height: 35mm /25 mm
Drop: 10mm per Adidas, 8.5mm per Running Warehouse
Classification: Lightweight Trainer


RUNNING SHOE SUMMARY

Matt: The Adidas Adizero SL is a lightweight trainer and faster entry-level shoe for those who want a firmer ride for uptempo training and workouts. A low volume but wider fit sits up top with a secure lock down but slightly loose tongue. The ride is firmer throughout with a majority of the midsole being Lightstrike with a forefoot piece of Lightstrike Pro. There is still plenty of midsole for daily training, but the lighter and snappier ride makes it an excellent choice for tempo runs and intervals. The Adidas Adizero SL is a great shoe for the entry-level runner looking to run faster or the experienced runner looking for an alternative to super shoes.

David: The Adidas Adizero SL is a daily trainer in the Adizero lineup aimed at providing lively transitions. The balance of weight and midsole composition also gives this shoe some appeal as a performance trainer. The SL uses a mix of Lightstrike and Lightstrike Pro foams combined with good traction and a lightweight frame to add a fun training shoe to the lineup. 

Nathan: The SL slides over from its own line and joins the Adizero lineup. With this shift came some really nice updates from the SL 20.3 and previous iterations, mostly related to geometry and some upgrades to the foam components. It is a non-plated, lighter-weight daily trainer with a bit softer ride than previous Adidas trainers sporting Lightstrike midsole and some additional pop from a Lightstrike Pro insert in the forefoot. In many ways, this is the update to the Boston 9 that many were looking for.

SIMILAR SHOES
: Brooks Launch 8, ASICS Evoride 3



FIT

Matt: The Adidas Adizero SL fits me true to size, if slightly short, in my US men's size 10. The width is slightly wider, especially in the forefoot. The volume though is quite low. The shoe initially felt short due to how low the upper at the forefoot sits on my toes. Those who like some height in their shoes up front will not like this, while those who want a low riding upper that still has room for the toes to spread a little will. The upper at the forefoot is thin and well-ventilated. It begins to thicken in the midfoot, with large Adidas striped overlays on the lateral side. The tongue is medium in thickness and not gusseted. I had some slippage of the tongue, especially with workouts involving turning. Tightening the laces helped a little, but seemed to put extra pressure on the dorsum (top) of my foot. The rearfoot is normal in width and features a ton of cushioning in the collar in front of a flexible heel counter. Those with sensitivities should be good with this, but should still approach with caution. Those who want a really stiff counter will be disappointed, but the extra padding locks in the heel decently. I had no security issues outside of some tongue slippage and did not have to lace lock this shoe. 

David: The Adidas Adizero SL fits true to size in my Men's 9.5. The width in the heel is slightly wide, midfoot normal, and forefoot wide. The mesh is of moderate thickness and is breathable enough for long daily efforts. The material itself is on the softer end of mesh materials and feels surprisingly plush for the amount that is present. The upper definitely leans more towards a daily training fit, though locks down pretty well for a performance feel as well. The tongue is moderately padded and is consistent with most lightweight trainers. The tongue also has a tendency to slide a little. The heel lockdown is okay, though I do use the last eyelet. For some reason I have struggled with the heel lockdown in Adizero lineup through 2022. As long as I tightened up the laces decently I didn't get any heel slippage. The volume is normal to slightly snug and still resembles that of a training shoe. The SL upper balances training comfort and performance feel pretty well. 

Nathan: The Adizero SL fits slightly wider than other shoes in the Adizero line but maintains the lower volume toe box consistent with other models. The length is true to size without any irritation despite the lower volume, and the layered mesh upper stretches well over the first few runs. The upper is a moderate thickness mesh that is built for durability and training yet still feels overall airy and light. The midfoot locks down well and the heel is a semi-rigid counter with nice padding. The tongue is probably my only issue as it is difficult to situate when putting on the shoe and folds over a bit when tying down the laces. Because of this and the shaping of the heel, I get very mild heel slipping, but not bothersome for daily miles. I only really notice it when trying to push the pace and wishing it felt a bit more secure. The collar and tongue could use refining, but overall it is a comfortable and well-fitting upper.


Matt's heel wear after 46 miles

PERFORMANCE

Matt: The Adidas Adizero SL is a lightweight trainer with a slightly firmer ride. The majority of the midsole is Lightstrike with a small amount of Lightstrike Pro in the forefoot. Oddly, while the overall ride is slightly firmer, the heel foam compresses and feels cushioned while the forefoot is firm and stiff. There is a large posterior lateral heel bevel that transitions the rearfoot fairly well. The forefoot has only a little forefoot rocker and is quite stiff. This makes for a snappy toe-off at faster speeds, but is slightly awkward at slower speeds until the shoe breaks in. Once the shoe breaks in, there is plenty of cushioning to function as a lightweight trainer for short to moderate distance daily miles. Once the pace picks up, the shoe starts to shine a bit more. Although not a race shoe for most, the Adizero SL excels at tempo runs and interval training. The slightly firmer ride is snappy on both the road and track, making it easy to pick up the pace. I found that the Adizero SL works extremely well for longer intervals, but does have the firmness to handle some shorter stuff, especially if you want to wait until the final repetitions to switch into spikes or super shoes. I did not really notice the Lightstrike Pro forefoot and found the ride to be typical of Lightstrike. It is a foam I have enjoyed and while not the fastest, makes the Adizero SL a great alternative to super shoes to provide a different stimulus for your legs.

The outsole traction has been quite good on a variety of surfaces. I have found it to be fine on both wet and dry road. It grips tracks extremely well and makes turning on the curves easy. It can be used as a trail shoe on well-groomed trails, but I would look at the Adidas Terrex range for more aggressive trails. Durability wise this shoe is holding up extremely well. The ride is softening with more miles and even after 46 miles, there is barely any wear on the outsole. I still expect this to last a normal number of miles sitting between the durability of the lightweight trainer and daily training shoe. 

David: The Adizero SL was a pleasant surprise for me. It filled some of the gaps I was seeing in the Adidas training lineup. For me the Boston was a little heavier than I'd like and the Adios a little too speedy for daily efforts. The Adizero SL falls right in the middle and provides an experience that is certainly adept for daily training but able to perform as well. The construction of the shoe is mostly Lightstrike with a bed of Lightsrike Pro throughout the core of the shoe. The ride still leans firmer because of the Lightstrike, but gives you a pop through the forefoot from Lightstrike Pro. The shoe has a moderate rocker geometry and consistently makes you feel like you are rolling forward. The outsole has good traction underfoot and you constantly feel like you are engaged to the road. The heel still feels a little firmer than the rest of the shoe and can make for a harder initial contact, though the rest of the shoe rolls very smoothly for me. I did also notice I would scuff the posterior lateral heel a little more in the SL. 

The Lightstrike Pro is definitely noticeable and comes alive when you start to push the shoe more. I have done multiple efforts over 10 miles fine in this shoe and have also done a 6 mile tempo run just off marathon pace with zero issues. It can handle some dirt and off road, though the quick rocker and slightly high feeling platform made me a little ginger in softer trails. This essentially is the lightweight trainer I have been waiting to see again from Adidas. 

Nathan: When the Boston 10 sneak peeks came out, there was a question whether the DNA of the Boston would be lost. In many ways, it was. It went from a lightweight, nimble, faster trainer to a heavier, high stacked, stiff rockered trainer. People who loved putting miles on the Boston 9 were left with trying the Adios 6, which didn't have the same trainer feel as previous Bostons. In some ways the Adizero SL steps into the lighterweight trainer space that the Boston 9 used to fill. There is a somewhat simple geometry with a really well-designed lateral heel bevel and a full contact outsole with a mild rocker and toe spring in the forefoot. Operationally the forefoot geometry is more flat and flexible, which is nice for ground feel. The foam is primarily Lightstrike with a forefoot insert (core) of Lightstrike Pro. This Lightstrike compound feels a bit softer than previous iterations, but still is on the mildly firmer end of the spectrum, but the Lightstrike Pro forefoot pod gives a bit of extra cushioning to sink into during transitions to the forefoot. The shoe performs really well for daily paces, but the Lightstrike Pro and lighter overall feel do allow it to pick up the pace well, making it a do-it-all trainer in some ways. The rubber outsole is not their lovely continental rubber, so the grip is average. The rubber choice combined with the longer "stripes" of rubber has made it more difficult to grip on snow-covered roads, but I still have taken it out in snow several times without feeling too unnerved.

Compared to other trainers in the Adizero line (like the Boston 11 at $160), the $120 price point seems reasonable for what is put into the shoe, the durability it seems to have, and the versatile nature of the shoe. Plus the Adidas website seems like it tries to give away their shoes with the deals they have, so just keep an eye out and you can probably snag this thing pretty cheaply. There is a moderate drop (8.5-10mm depending on your source), but the geometry is such that it would suit people who prefer anything from 6-12mm.




STABILITY

Matt: The Adidas Adizero SL is a neutral shoe. There are no traditional elements of stability in this shoe. The width of the sole in the midfoot is quite narrow. However, the arch runs a little high on the medial side. Those who want a higher arch with a narrow shape will like this shoe. The heel features a significant posterior lateral heel bevel. This keeps motion more lateral at heel landings. Those who need a bit of lateral guidance will like this, while those who deviate too lateral may not. The forefoot is the most stable part of this shoe. It features sole flare on the medial and lateral side. The midsole stiffness is particularly noticeable up front, creating some resistance to torsional rigidity. Those who want a stable forefoot due to sole flare and ridigity with lateral bias at the heel will enjoy the Adizero SL.

David: The Adidas Adizero SL is definitely a neutral shoe. There is no formal stability measures present, though the shoe does well. The shoe uses a lot of sole flaring in the forefoot which helps give you a stable toe off. The play between Lightstrike and Lightstrike Pro is done pretty well and keeps you feeling centered with a slight bounce. The upper locks down well and does have too much stretch to it. The heel feels a little high and could be rounded a little more in the posterior lateral bevel to prevent that floating feeling. It isn't that much of a problem on roads, but it makes dirt or grass a little tricky at times. Underfoot traction is pretty good throughout. 

Nathan: The Adizero SL is a neutral shoe without any formal stability or guidance. The firmer midsole foam, full contact outsole, and wider forefoot do allow for a nice platform for daily mileage and longer runs, as significantly softer foams can place more demand on your stabilizers. The bevel is Adidas' classic lateral bevel that has been seen regularly since the first Adios Pro, but slightly less severe than some of the racing models. Therefore I believe this helps guide the foot forward well for rear-foot strikers. The forefoot is wider and is stable for toe off. The cutouts present are cosmetic and do not affect stability. 


Thoughts as a DPT: A Case for Shoe Variety During Training and Workouts
By Matthew Klein

Despite the continued excitement around super shoes, we at Doctors of Running have continued to suggest using a variety of shoes not just for daily training but also for workouts. One reason for this suggestion is that using a rotation of shoes is one of the few things that have been found to decrease injury risk (Malisoux et al., 2015). The other more in-depth and less defined reasons are that we are still unsure of the impacts of some of the new super shoes on our mechanics and tissue physiology. It isn't that these types of shoes are bad, but whenever you spend large amounts of time in something, your body will start adapting towards it. Whether the adaptations are good or bad is what we do not know. 

Thus far, we know that compared to traditional shoes, super shoes tend to make the greatest biomechanical impacts at the ankle. Studies have suggested that there is significantly decreased ankle work and dorsiflexion angles in these shoes compared to traditional footwear (Hébert-Losier et al., 2022; Hébert-Losier & Pamment, 2022; Hoogkamer et al., 2019). There is also evidence that our bodies change how we shock absorb in these shoes, with runners tending to land with far stiffer mechanics in super shoes compared to traditional shoes (Kulmala et al., 2018; Pollard et al., 2018). This may explain why despite the continued progress in footwear development and increases in cushioning, running-related injury rates have remained consistent.

Whether these changes are good or not is controversial. There are continued reports of decreased delayed onset muscle soreness following hard training in these super shoes. We are seeing incredible performances across all distances, with records dropping at increasing rates. From a tissue adaptation standpoint, we don't know what is happening. 

We have discussed repeatedly that these maximalist, rockered shoes reduce stress on the Achilles tendon (Agresta et al., 2022). This can be fantastic for someone with Achilles issues to train through irritation. However, the Achilles tendon, like any other tissue, maintains or increases its tensile strength and stiffness in response to appropriate loads. Reducing those loads consistently may have negative consequences on the tensile strength and stiffness of the tendon (Agresta et al., 2022). 

It is for that reason that we also suggest having a variety of shoes to do workouts in. The Adidas Adizero SL fills the gap quite well as a more traditional uptempo/workout shoe that may provide some greater contrast to the super shoes of today. Additionally, the Adidas Adizero SL is a far better option for beginners to get used to faster running without adding the additional variable of the influence of a super shoe. These shoe types still have an important place both for those transitioning to faster running as well as changing up the types of loads and stresses experienced runners go through to maintain well-rounded and resilient tissues. 

Sources:

Agresta, C., Giacomazzi, C., Harrast, M., & Zendler, J. (2022). Running Injury Paradigms and Their Influence on Footwear Design Features and Runner Assessment Methods: A Focused Review to Advance Evidence-Based Practice for Running Medicine Clinicians. Frontiers in Sports and Active Living4, 815675. 

Hébert-Losier, K., Finlayson, S. J., Lamb, P. F., Driller, M. W., Hanzlíková, I., Dubois, B., ... & Beaven, C. M. (2022). Kinematics of recreational male runners in “super”, minimalist and habitual shoes. Journal of Sports Sciences40(13), 1426-1435.

Hébert-Losier, K., & Pamment, M. (2022). Advancements in running shoe technology and their effects on running economy and performance–a current concepts overview. 
Sports Biomechanics, 1-16.

Hoogkamer, W., Kipp, S. & Kram, R. (2019). The biomechanics of competitive male runners in three marathon racing shoes: a randomized crossover study. Sports Medicine, 49(1), 133-143.

Kulmala, J. P., Kosonen, J., Nurminen, J., & Avela, J. (2018). Running in highly cushioned shoes increases leg stiffness and amplifies impact loading. Scientific Reports8(1), 1-7.

Malisoux, L., Ramesh, J., Mann, R., Seil, R., Urhausen, A., & Theisen, D. (2015). Can parallel use of different running shoes decrease running‐related injury risk?. Scandinavian Journal of Medicine & Science in Sports25(1), 110-115.

Pollard, C. D., Ter Har, J. A., Hannigan, J. J., & Norcross, M. F. (2018). Influence of maximal running shoes on biomechanics before and after a 5K run. Orthopaedic Journal of Sports Medicine6(6), 2325967118775720.



RECOMMENDATIONS

Matt: The Adidas Adizero SL is a fun, simple lightweight trainer that has been a great shoe for me to use as a break from super shoes during workouts. It provides enough room while still being secure and has a firmer/snappier feel underfoot when the pace picks up. I suggestions revolve around the tongue and the Lightstrike Pro in the forefoot. The tongues slides a decent amount, so I would highly suggest either integrating it into the upper or gusseting it. This would dramatically improve the security of the tongue especially with turning. To be honest, I could not tell there was Lightstrike Pro in the forefoot. The heel feels softer due to the higher stack height and the forefoot was stiff and firm. I would encourage Adidas to use a taller amount of Lightstrike Pro and even consider making the entire forefoot that material. This would drastically improve the responsiveness of the forefoot as it feels fairly average at the moment. 

David: I really enjoyed my time in the Adizero SL. With that said I still have some things that would improve the shoe. The heel geometry could be rounded a little bit more. I felt like I would land a little early and have a floating sensation before transitioning onto the rest of the foot through loading response. This was really evident off of road conditions. The upper is done pretty well, though I think upper security in the heel could be improved. I still experienced heel slippage if I did not use the last eyelet or lace tight. The tongue padding is pretty good, but it does slide. I think securing that would make for a more pleasurable experience. 

Nathan: I'm excited that this shoe was added to the Adizero Line. The SL20 was nice, but lacked refinement for a true workhorse trainer. I think that updates to this shoe are mostly related to fit and outsole. I think it's important to keep the price point at $120, but if we can upgrade to Continental rubber, that would be great (though asking for more in a shoe without an increase in price is a tough ask). I also think that the tongue needs some work to lie more flat and be more comfortable. 

WHO THIS SHOE IS FOR


Matt: The Adidas Adizero SL is for those who want a lightweight trainer/workout shoe with a slightly firmer ride, a stiff toe-off and a wider/lower volume upper. The full-length Lightstrike midsole is snappy underfoot, while the forefoot Lightstrike Pro seems to firm up the forefoot more. The upper is thicker and secure despite a wiggly tongue, with a wider but low sitting upper especially over the toes. The Adizero SL is a great shoe for a variety of runners: it's great for those who want something lighter for daily training, it's a solid introductory faster shoe for newer runners, or it can be a great alternative to super shoes for experienced runners trying to keep their bodies well-rounded. 

David: The Adidas Adizero SL is a light weight trainer that functions as a Swiss Army Knife. The shoe is able to do a little bit of everything without much issue. The shoe has a balanced rocker throughout that keeps you feeling like you are rolling forward. The dual density midsole gives you a nice bounce through the forefoot, though maintains balanced cushioning and a sense of firmness. This is a light weight trainer that gives you a slightly firm rocker experience and a fun bounce at toe off. 

Nathan: The Adizero SL is a lighter weight versatile trainer that may be the update to the Boston 9 that many were looking for. It's a trainer for someone who wants a flexible forefoot, moderate stack, and slightly firmer cushioning, and would work well for someone looking for a shoe to do daily running and some workouts in. At the $120 price point with almost guaranteed sales from Adidas, this could be a great budget pick-up over the next year.


GRADING

Matt
Fit: B+/A- (slightly wider forefoot with lower volume fit. Tongue slides, but rest of upper still secure)
Performance: 
A- (Solid shoe for short to moderate training distances and workouts from tempos to intervals)
Stability: B [Neutral] (Narrow midfoot/heel. Sole flare in forefoot with stiffness makes for better stability up front. Best for those with neutral mechanics or who do not want any stability/guidance measures)
DPT/Footwear Science: B/B- (Inadequate use of Lightstrike Pro that ends up firming forefoot up more.)
Personal: A- (A great simple lightweight trainer)
Overall: B+ 

David
Fit: (Heel lockdown could be better. Tongue could be more secure. Otherwise really nice and comfortable.)
Performance: A- 
(A great balance of smooth transitions and responsiveness. Heel could be rounded a tad more.)
Stability: B+ (Good traction. Decent Lockdown. Heel gives a floating sensation. Could be a little better in off road conditions.)
DPT/Footwear Science: A- (A good balance of Lightstrike Pro and Lightstrike that makes you feel connected and centered to the shoe.
Personal: A (Outside of the heel scuffing this shoe works very well for my mechanics and checks nearly every box.)
Overall: B+/A-

Nathan

Fit: B+ (Solid, but tongue is a bit sloppy)
Performance: 
A (Really smooth for daily training, versatile enough and comforatble for whatever I've done)
Stability: B [Neutral] (No guidance features, but not unstable by any means)
DPT/Footwear Science: B+ (Nothing remarkable, but that's what is done well for daily trainers)
Personal: A (Wouldn't be surprised if this is my trainer of the year in 2023)
Overall: B+/A- 
 

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FURTHER READING

The Best Performance Trainers of 2022
Brooks Ghost 15 - The iconic every person trainer returns with some nice updates that keep things fresh, but also familiar
Mizuno Wave Rebellion Pro - Mizuno's new super shoe is here
The Best Max Cushion Shoes of 2022
Brooks Levitate 6 - A daily trainer for those who like a firmer, rolling ride
Brooks Levitate 6 GTS - The stability cousin with guiderails

Find all Shoe Reviews at Doctors of Running here.

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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 Running Warehouse and Adidas for sending us a pair.  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 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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The Best Max Cushion Shoes of 2022
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