Adizero SL is for runners with an average build, medium to narrow heel, and medium forefoot who prize comfort and stability in a light shoe. Wear it for tempo runs, long runs, and recovery runs; it will serve most of your daily training needs.
Runners with a narrow forefoot may find the medium-width toe box too roomy, while those with a wide foot may feel claustrophobic. Those who wear down midsoles quickly should avoid the less-dense foam of Lightstrike and perhaps look for a model with the resilient (but heavier) Boost midsole from adidas.
The adidas Adizero collection includes shoes, cleats, and spikes for football, tennis, baseball, and, of course, for running, all geared toward the Adizero catchphrase, “Light makes fast.”
Adizero SL encapsulates this goal in its name which stands for “Super Light,” which is true when comparing it with other shoes with comparable midsole thickness and upper support.
This shoe replaces the brand’s SL20.
My introduction to Adizero was with their now-discontinued Adizero Tempo 9, a low-profile trainer with just the right amount of Boost foam (a thin layer) and support. I found the same snug, comfortable fit in the Adizero Pro, a trimmed-down racer with a carbon plate that I save for 5k races.
Similar to the Adizero Pro is the Adizero Adios with its extremely thin upper and stiff ride geared for speed. Look for a review of the Adios 7 coming soon, but for now I’ll say that Adios fits about a half-size longer than the other Adizeros I’ve run in.
Adizero RC has a full-length Lightstrike midsole while the Taumi Sen is maxed out with full-length Lightstrike Pro.
Finally we come to the Adizero Boston which has a thicker midsole than the rest, similar to our shoe of focus in this review, the Adizero SL. The Boston 11 includes a nearly full-length layer of Lightstrike Pro over a Lightstrike base, which I would expect to add a touch more softness and also instability underfoot.
The Adizero SL is the budget-friendly version of the Boston, carrying less of their top midsole foam but also ringing up $40 lower, with a list price of $120 USD.
The SL weighs 8.6 oz. for men’s size 9 and 7.4 oz. for women’s size 7; it is very light for a shoe with this much midsole and substance to its upper. The weight is .3 ounces less than my old Tempo 9, with more midsole cushion, and is only a half-ounce more than the line’s racer, the Adizero Pro (based on my women’s size 9.5).
Other similar shoes include the Puma Velocity Nitro, New Balance FuelCell Rebel, Nike Pegasus, and Reebok Floatride Energy. There are so many technical features to this shoe that this review will cover more similar shoes in the Upper and Sole sections.
First picking it up, I was impressed by the light feel. Trying it on brought a smile with the familiar comfort I’ve come to expect in Adizeros.
My first run was a happy 10-miler on a cold but clear day just after a winter-blast snowstorm. I loved the lightweight cushion and appreciated the firm Lightstrike under the heel to keep it from feeling too squishy.
Now with more miles on the shoe, I still love running in it and choose it over heavier daily trainers. The ride feels the best when picking up the pace with a focused midfoot strike as the transition into toe-off are a bit “blocky,” not smooth and fast-feeling, when settling into an easy pace with more of a heel strike.
Adizero SL sports a soft engineered mesh upper with a thin neoprene-looking cap supporting the tip of the toe with the same material housing the logo on the medial side and running up the back of the heel. The lataral logo strips are about twice as thick. Another rectangular patch supports an opening in the tongue for laces to run through, which helps to keep the tongue in place.
It fits true-to-size.
The heel & tongue are moderately padded for comfort over long workouts without a lot of extra weight. A mid-grade internal heel counter is bolstered by thicker neoprene(?) support strips on both the lateral and medial heel, with a similar internal/external construction offering durability to the lace holes.
The front two laces run through loops resembling Nike Flywires, but they attach to the internal support piece about a centimeter below the opening rather than running down to the midsole. The medium-width laces do not dig into my foot due to padded tongue, but the extra-wide tongue has a tendency to bunch up when tying, since it lacks an internal booty-type attachment to keep it anchored, such as found in Nike Odyssey React and the older ISOFIT uppers from Saucony. This “bunching” is easily avoided by pulling the tongue taut horiontally before tying.
One final design piece to note is a small pull-tab on the top of the heel to aid in putting the shoe on.
This upper uses at least 50% recycled materials.
Adizero SL runs on a base of Lightstrike, a medium-density EVA foam that sits between the brands Bounce and Lightstrike Pro formulations. The heel at 35 mm. drops 8.5 mm. down to 26.5 in the forefoot.
With about 80 miles on the shoe when the photos in this review were taken, you can see compression lines developing in the Lightstrike midsole which makes me wary of its ability to hold up to many miles of pounding for those who tend to wear heels out quickly.
Lightstrike is a less-dense version of the brand’s EVA Bounce midsole, which makes it lighter. It has excellent spring-back, but the lower density means it will show wear more quickly.
That said, now with 100 miles on the shoe there is no dip below the ball of my foot, into the softer Lightstrike Pro, as I remove the sock liner and run my hand through to test for compression, which speaks to durability. In addition, there is still plenty of bounce-back when pushing up on the sole.
For comparison, a noticeable dip was apparent at 100 miles when running in Nike’s supper-soft Lunarlon foam.
This cream-colored Lightstrike Pro material peaks through two small cutouts in the sole under the forefoot. The softer Lightstrike Pro reminds me a lot of Nike’s squishy-soft React foam and FLIGHTFOAM Blast from ASICS.
In Adizero SL the combination of Lightstrike in the heel with Pro under the forefoot, framed by Lightstrike along the sides, brings stability to the ride.
This construction is similar to the Adizero Adios 6 and 7 and allows for a more stable footplant than a full React or FLIGHTFOAM Blast midsole, yet a softer feel under the ball than in a full-length Lightstrike midsole such as found in the SL20 which the SL replaces; the softer feel is also aided by almost twice the thickness.
Robust rubber grip-lines run in narrow diagonal strips down the full length of the outsole offering high grip in most conditions. Doing a lot of running in snow and slush this winter in the Midwest United States, I can attest that the grip helps. Snow packs into the spaces between lines quite readily, though, and I find myself scraping off the excess and stomping my feet as I run from snow onto a cleared surface to regain some traction.
The rubber outsole curves up the medial tip to provide a buffer for incidental scrapes in toe-off.
One final note about the outsole is that a vertical line splits the rubber for most of its length, limiting the horizontal force transferred during pronation.
The Adizero SL is one of my favorite everyday shoes for mid to long runs as well as comfortable casual wear. I really want to give this shoe full stars but hold back because I hope adidas improves the transition into toe-off for future models.
All around it is a fabulous shoe for the money, especially for those who appreciate some firmness to the midsole for stability underfoot but also a softer material to cushion the impact below the ball.