Adidas Boston 9 Performance Review

What You Need To Know

• Lightweight trainer at 8.4 oz. (238 g) for a US M9.
• Features combination of Lightstrike and BOOST midsole
• More breathable open mesh upper; classic Continental rubber outsole provides excellent traction
• One of the best adidas options out there that gets it all done

DAVE: Many have loved the Boston series going way back into the archives. In my honest opinion, the Boston 8 (with Boost midsole), as well as earlier editions, were some of the most effortless trainers out there (and still are to this day)! Over the years, I’ve had some of my most “enjoyable” runs in the Boston.

So here we are with the Boston 9, with a new-ish Lightstrike foam layer (EVA that’s meant to be lighter and softer without sacrificing energy return).

If I’m going to be honest, Lightstrike has ruined some of my favorite shoes in the last six months (see: Adios 5 and SL20), topped over the Boost midsole like a licorice layer on an ice cream sundae. None of these offerings were honestly that bad, they just didn’t have the snap off the forefoot I have loved for years from just plain Boost. Lightstrike is just a bit lifeless to me.

Personally, I feel that Boston is a daily trainer. I don’t tend to train in anything over 10 oz. as is, and there are far faster workout day shoes hanging around. For others, including athletes I coach, the Boston is just like how Adi markets it. A nice, up-tempo trainer that can be also raced at the full and half mary distances. I’ve seen a ton of success from athletes working out and racing in this model as well.

Now that I’m done gushing on the Boston, let’s dive into the dirty deets on the all-new Adizero Boston 9 and see if the Lightstrike did this in.

JEREMY: The Adidas Boston has been a staple lightweight trainer for years now, it’s known as a versatile shoe that can be used for road racing, workouts, and even every day running. The Boston 9 is no exception, updating the upper for a lighter and better fit and utilizing the semi-new Lightstrike midsole material.

After the recent SL20 release, my first impression of the Lightstrike foam was average. It performed well but wasn’t anything special. For me, this didn’t bode well as the midsole was a centerpiece of their new lineup featuring the SL20, Boston 9, and the Adizero Pro racer. After about 80 miles of Boston 9 running, I’m willing to say that first impressions aren’t everything– these shoes have some juice!

The Good

DAVE: Fit: I throw this disclaimer out there all the time about my feet, but here you go again. I have a narrow foot, size 9 with an average-to-higher arch. I like my shoes locked and loaded like a racer, no matter if it’s a trainer or a shoe made to rip some quarters.

The first Boston 8 version (with Lightstrike) had the shallowest internal volume of any shoe I’ve put on my foot in a long time. And even for my narrow foot, the toe box was so darn crammed, my feet would fall asleep on a run. However, the second version of the Boston 8 with just Boost fit fine. No clue how that fit got so bad in literally 6 months. But hang on here.

Good news– the Boston 9 comes in much improved from immediate lace-up. For you average-to-wider foot runners, the Boston 9 can now be an opportunity to add to the shoe rack. The internal volume underfoot (within the shoe) is much deeper, allowing the foot to settle in nicely. The tongue has been changed to almost mimic one of the softer leather tongues on old school Adi Classics and rests nicely along the top of your foot.

A dual-layer open mesh upper, combined with the coolever mesh lining offers much more splay and a more trainer-like feel compared to the Boston 7 and 8, which even for my foot still ran on the narrow side of things. I’m very impressed with the new fit.

Now onto Lightstrike: After bashing this new foam above, I have to tell you– it works on the 9. Boston is back, baby! Since receiving this shoe, I’ve had some of the best easy aerobic days in a long time. The shoe works with my mechanics and it fits my foot perfectly, wrapping nicely around my arch. When I’m locked in like this, I get to feel the entire makeup of the shoe, and that includes really paying attention to the mid load phase of my gait, powered into the toe-off. The Boston 9 is so damn smooth you really don’t want to end your run. It transitions effortlessly and makes mile after mile a thing of mechanical beauty on the freshest of legs.

Colorway: Jeremy and I received the B.A.A. colorway that was supposed to be released for this year’s Boston Marathon (the April version)– I think it is pretty rad. I love the B.A.A. markings on the heel counter and the nice addition of light red on the medial arch running into the medial heel adds some life. The Boston 9 also comes with some navy blue laces that add a fresh look to a shoe that has always looked good on my foot.

Outsole: Continental rubber as per usual from Adi. Grippin’ like gravy on those Thanksgiving taters.

JEREMY: The upper is a light breathable mesh that fits snugly and securely– it’s a perfect combination of sleek design, yet rigid enough to keep your foot locked into place on the sides. There’s clearly great attention to detail in this design; even the tongue is padded and gusseted so it feels soft against the top of your foot without sliding.

The outsole is Continental rubber and is absolutely top-of-the-line for grip. I even took these shoes out for a cross country Fartlek workout through the grass and mud on a rainy day and had no problem picking up the pace. Adidas is top of the game in terms of the outsole rubber options out there.

The midsole is a winning combination of Lightstrike foam that has been touted by some and doubted by others (including Dave and I after reviewing the SL20 recently) and the already proven Boost cushioning used in previous Boston editions.

The difference between the Boston and SL20 is night and day to me, the ride combines a wide extended torsion system with this combo foam midsole to give a cushioned yet fast feel. This shoe felt comfortable on easy runs, fast during workouts, and held up stoutly on long runs. In an homage to its hilly marathon namesake, I took the Boston 9 out for a 20-miler on a rolling route I affectionally call the ‘Quad Killer’. After a few miles, I decided to pick up the pace and drop some mid 5-minute miles and got into a rhythm– this shoe can move! After 20 miles and 1500+ feet of gain, my legs were feeling it, but the cushioning held up well for the distance.

While the Boston Marathon may not be happening this spring, aesthetically, the Boston Marathon colorway still looks sharp as a predominantly-white shoe with red accents on the forefoot, silver stripes, and blue BAA unicorn logos on the heel.

The Bad

DAVE: Heel Slippage: My only quam with this shoe is out of the box I got a bit of a blister on the back of my right heel. I never blister (just jinxed myself for my next Marathon or Ultra, I’m sure) but it will be something I continue to pay attention to. To note, there is no real movement back there however.

JEREMY: Similar to Dave, I also noticed some heel slippage with the shoe, but this was fixable using the extra lacing eyelet for heel lock lacing. Otherwise, I have no complaints.

Adidas Boston 9 Conclusion

DAVE: One of the smoothest shoes around right now. Perfect for all types of runners and gaits. As a coach who also used to teach biomechanical clinics around the country, I can tell you the Boston 9 is a great exploration for the runner looking to improve some mechanics in a safe and natural way. It creates a nice forward lean, and with a nice snappy toe-off, gives a good amount of the required knee lift and drive to make those runs feel like you’re rolling through Eldoret. Well maybe not, but you know what I mean.

Looking for a lightweight option that will last forever? Here you go.

JEREMY: We have a winner here, definitely my favorite Adidas shoe worn to date. If you’re looking for a shoe with range, this is a good bet. It’s got bounce, it’s got cushion, and it’s lightweight enough to be worn for just about any type of run. Personally, it’s already in my everyday rotation and is one of the few shoes I would consider wearing for daily mileage, workouts, and racing.

It has a track record of durability, looks pretty sharp, and at a discounted $89 right now (since Boston has been postponed), it’s an insanely good price point.

You can pick up the adidas Boston 9 at Running Warehouse (featuring free 2-day shipping and 90-day returns) by using the shop link below.