History of Boost:
“Wait, Adidas makes running shoes?” Oh yes, the thought of many runners the past decade or so until the landmark year of 2012. This was the year that Adidas fist unveiled their “Boost” technology and ultimately gave new life to their running shoes (metaphorically and quite literally!). Ok so what is Boost you might ask? Well you can thank some chemist in Germany (HERE is a good article giving a little history); who designed this midsole material. The full name of TPU Boost being “Thermoplastic polyurethane” or TPU for short, is a type of plastic (as is EVA - "ethyl vinyl acetate," the common midsole material of many running shoes). What separates TPU from EVA and other midsole foams is that TPU are little spherical units that are globbed together to form a slab of midsole material. You will notice when looking at the midsole of Adidas’ running shoes how it doesn’t have a nice smooth finish. This is because as I stated above, the material is welded together with many individual units that work together as one – cool eh? EVA and other midsole materials on the other hand are one continuous piece(s)/mold of midsole material formed into a shape. This can be accomplished in many ways. If you want to really geek out over this here’s a link to a site that does a decent job explaining the different type of running shoe midsole technologies- HERE. Ok so enough rambling on that and onto the review of the Adidas Adizero Boston Boost 6.
So many will be wondering how in the world can Adidas update arguably their best shoe in their running lineup? Easy, don’t mess with the general formula, make small tweaks here and there, and what do you end up with? A piece of art (ok maybe I’m taking that a little too far), but seriously this shoe rocks! They must have some mad geniuses at Adidas, because the last couple of years has resulted in many of their shoes gaining praise from elite athletes to hobby runners. I’ll admit that I am a bit of a fanboy now, as I own many of their running shoes…. Takumi Sen 3, Adios 3 (see my review HERE), Boston 5, and now the Boston 6. Well without further ado, let’s analyze and dissect this beautiful specimen of a shoe!
Adidas once again does not fail to impress on the design of this shoe. Adidas updated the upper material (more below) and this adds to an even more streamline appearance and results in an aesthetically pleasing shoe. Also, when looking at the colors online they do not do the shoes justice. The white and orange is A LOT brighter than it looks and the blue is more of a metallic blue. For those who do not like super flashy colors, they just released an all-black version. I just wish there was a purple version…. oh well I continue to wait!
Additional images from runninwarehouse.com as noted.
(thanks to Running Warehouse®)
Heel to Toe Drop – 26mm heel 16mm forefoot
Weight – 8.8oz men’s size 9, 7.5oz women’s size 8
Price – $120
Colorways –white/white/red, blue/blue/steel, black/black, mystery blue MEN, Blue/Blue, Pink/Pink, Black/Black, Mid Grey/White WOMEN
Disclaimer: Sorry ladies, but the newest colorway “Mid Grey/White” looks like it belongs in the 80’s. But who am I judge? Just wanted to give a buyer beware.
Fit and Upper:
My all-time favorite aspect of all the Adidas running shoe line…. SNUG FIT! Honestly, if you have a slim foot or narrow heels you will appreciate the fit and upper of the Boston 6. When compared to the Boston 5 though (which I got 700+ miles out of my pair); the Boston 6 is more forgiving. The tongue is more padded and a hell of a lot more comfortable on the top of the foot. The breathability is identical to the 5’s, but the mesh material is a bit softer and has an overall plusher feeling on foot. The midfoot is held firmly in place and most importantly the heel. Seriously, I don’t know what is up with the other brands (I’m looking at you Saucony and Brooks), where you have a narrow forefoot but a cavernous midfoot and loose heel? Fear not as the Adidas Boston Boost 6 has a narrow fit – which only makes sense because most people’s heels are the narrowest aspect of their foot. The secure hold in the heel allows for a wonderful ride (more to come below) and makes it so you have 0 rear foot slippage/sloppiness. I also appreciate the orientation of the lacing. It seems that Adidas made it slightly eccentric, which contributes to a more efficient lacing system. Some shoes have too narrow of laces, weird eyelet spacing, and/or just weird materials. Adidas, as with all their shoes, are a master of classic lacing that just works!
Yes, even with the narrow-fit I still use the last loop. This is to prevent me from over cranking the laces on the top of my foot. But you can appreciate the “off-set” or asymmetric lacing used in this version of the Boston.
Midsole and Ride:
If you have read my review of the Adidas Adios Boost 3 (see review HERE), you will know how much I love the Boost midsole material (See intro section). In this section I will compare it to the Boston Boost 5 as there is differences between the two iterations. The Boston 5 was firmer underfoot, less flexible, which contributed to a harsher ride. Granted, I used the Boston 5 as my daily trainer/long haul shoe, but I overall enjoy a firmer riding shoe. The Boston 6 on the other hand, has a smoother heel to toe transition and a bouncy forgiving ride. I feel that this must be correlated with two things – first being that Adidas rearranged the tread pattern of continental rubber, and secondly the durometer (or hardness) of the outsole rubber has been decreased. This gives a softer forefoot feel and an increased flexibility. The result? A shoe that feels like an everyday trainer, but with the added benefit of the boost midsole. In other words, this shoe is super bouncy, moderately cushioned, flexible, with a wonderful turnover. Note: The boost midsole lives up to its name in regards to temperature and durability. I ran in 110+ degree desert heat when I lived in Las Vegas and single digits up here in upstate New York. The boost remains consistent despite these temperature extremes and I managed 700+ miles out of my Boston 5’s and currently about 300 on my 6’s and still going strong.
Note, the different layout of the outsole. Seems to help increase flexibility in the forefoot giving a more relaxed ride and softer forefoot.
All I can say here is, why can’t other shoes match Adidas’s durability?! Honestly, 700+ miles out of my Boston 5’s, 600+ miles out of my first pair of Adidas Adios 3’s, and 800 miles on my Trail Response Boosts. The part of the shoe that will make you need a new pair is the continental rubber, which starts to wear away around 300 miles. I have noticed that compared to my Boston 5’s that the continental rubber nubs in the forefoot of the shoe are wearing approximately 200 miles sooner. Not a deal breaker by any means for durability and again I think it must do with them decreasing the durometer of this material in the forefoot. When the outsole starts to wear, you will first notice the nubs starting to flatten out, but you shouldn’t appreciate degradation of the Boost midsole until about 400-500 miles. I should point out again that I am a small guy (140lbs 5’10”) who is rather light on his feet. So, keep that in mind ☺.
On the top picture, you can appreciate that the nubs of the continental® rubber is starting to smooth out. It’s hard to do a direct comparison though, as the forefoot tread pattern is different from the Boston 5 which lacks the “nubs” – bottom picture.
Rooms for Improvement:
I honestly can’t think of any. Adidas please don’t screw with this shoe, thanks! Oh, and purple colorway please!
A fantastic improvement (albeit a few small tweaks) that has made a great shoe even better. This shoe is my work horse and is comfortable for my 14 to 26 mile long runs and every day runs ranging from up tempo to easy runs of any length. Overall, a fantastic daily trainer and I feel that the increased cushioning has allowed this to become Adidas’s light weight trainer and separated it from the Adios (which in my opinion is the true long distance racing flat). Thus, if you were a fan of using the Boston 5 as your racing flat I suggest looking to the Adidas Adios Boost 3 (see review here). If you are not a fan of the other light weight trainers, can’t do/dislike the 0-6mm drop of more “minimalistic” light weight trainers, give these shoes a shot! I do not think you will be disappointed.
Happy running and to quote my friend Matt, “Tack on!”
Stick around and I’ll have a piece for Matt to post about selecting an appropriate doggie running partner and some things to consider for the safety and health of your pet from your running Veterinarian ☺ Stay tuned….
These opinions are my own, these were a personal purchase, and I received no monetary compensation for this review. -Dr. Kolias, DVM, MPH
Editors Note: As always, the views presented on this blog belong to myself or the selected few who contribute to these posts). My blog should not and does not serve as a replacement for seeking professional medical care. If you are currently injured or concerned about an injury, please see your local running physical therapist or medical professional.
Currently Dr. Kollias has over 300 miles on his current pair of Boston 6s. We put at least 75 miles on trainers and 25 miles on racing flats prior to reviewing them.
Thanks for reading and don't forget to tack on (as Dr. Kollias already mentioned)!
-Dr. Klein, PT, DPT and Dr. Kollias, DVM, MPH