My first impressions of the Boston 12 were not that good. I was expecting a super-trainer to replace my old, but precious, Saucony Endorphin Speed 2, but the Boston 12 are notoriously firmer and less bouncy. Despite that, I took the Boston 12 to the 100km (62 mi) mark, doing all types of runs with them, and in the end, I was surprised.
Introduction
The Adidas Adizero Boston 12 is a high-stack workout shoe from the Adizero family and for some time runners have been complaining that the Boston is not what it’s used to be. In this 12th iteration, Adidas revamped the Boston hoping to bring its glory days and now it’s lighter, softer, and bouncier than the previous versions.
I bought these running shoes essentially for speed workouts and I already logged more than 100 km (62 mi) with them.
Stats
Upper
As usual, from the Adidas Adizero family top performers, the upper is pretty basic. The Boston 12 mesh upper is made of a very thin and plasticky fabric. It’s very breathable and light, but it’s not a comfortable upper. I don’t need a comfortable upper for my workouts, but because this is also a running shoe that targets the long run, a comfortable upper would be appreciated.
I didn’t get hot spots on any of my runs with the Boston 12, but I can definitely feel the rigid fabric in some points of my foot. And after a long run, it’s noticeable that we are not running in a comfortable upper.
The back of the Boston 12 is the most comfortable section of the shoe. The inner fabric that surrounds the heel area and tongue is smooth to the touch and it’s a nice addition to the shoe. The heel collar only has a small amount of padding below the ankles, which will contribute to better comfort and fit, and that’s it. As expected, the Boston 12 features the typical Adidas pull tab that you can hide away while running, and you're going to need to use it with this shoe because it's not easy to slide in the foot without having to unlace it more than I would like. The lacing system is not as bad as the Takumi Sen 9, but it’s still bad. The laces are too thin for me and they did get loose on a workout (it only happened once).
The heel counter has some rigidity, not much, but I would say that’s enough for a workout shoe. It should improve the lockdown and overall running comfort.
Moving to the tongue, it’s a non-gusseted tongue, but it has a loop to fix it with the laces so it will not slide to the sides while running. The tongue has a small amount of padding that should be enough for a workout shoe but is not enough for longer runs.
The toe box is roomy as you could guess by the wide platform, but the harsh fabric will make you feel that you are running in a snug shoe.
Midsole
The Boston 12 has a high-stack midsole with two distinct foams. First, we have a full-length LightStrike Pro foam, with a higher stack in the forefoot, and below we have a full-length EVA-based LightStrike 2.0 foam, with a higher stack in the heel.
The LightStrike 2.0 is softer than the previous version but it’s still somewhat firm. I will still say that it’s inside the soft foams range, but it’s in the border with the firmer ones. So, if you like soft foams, the Boston 12 might not be for you.
Between both foams, you’ll find the fiberglass Energy Rods. These Energy Rods are small tubes that run along the shoe and have the same purpose as a plate. Limit the energy loss and increase the energy return. The Energy Rods are exposed by a cutout in the bottom of the midsole. Besides exposing the Energy Rods, this cutout is also removing some weight from the shoe.
There’s also another cutout on the forefoot's outer side, but it’s mostly for aesthetic purposes, to keep the same design as other shoes from the Adizero line. The cutout is too small to make any significant difference in the shoe performance, but it will reduce some weight nevertheless.
The midsole is quite wide on the forefoot, so forefoot strikers will have a great landing platform and this wide platform is also helpful in achieving a good toe-off.
I didn’t find significant differences in the midsole after 20 km (12 mi), but the midsole seemed softer. I can’t say for sure if the foams need a break-in period, but a break-in period of 20 km (12 mi) will be enough.
Regarding the midsole durability, the EVA-based LightStrike 2.0 is already filled with deep wrinkles with only 100 km (62 mi) so it seems that this EVA foam will lose its properties sooner than the LightStrike Pro which has no wrinkles so far. It will last 500 km (300 mi) for sure, but I doubt that it will last 800 km (500 mi).
Outsole
Continental rubber. Do I need to say anything more?
The outsole features the well-known Continental rubber that entirely covers the forefoot and has two stripes strategically placed in the heel to protect the higher impact zones. Usually, I prefer less rubber on the forefoot to save some weight, but this rubber is so grippy that I really felt it sticking to the tarmac when doing some strides. So, yes, it could have less rubber, but it’s doing its job perfectly.
I was unable to test it in the rain, but I ran over wet pavement and, as expected, I had no problem.
Not only it’s grippy, but it’s also durable. With more than 100km (62 mi), I can’t see any sign of wear.
Fit
I can’t securely lock the heel so I am unable to get a perfect lockdown in the Boston 12. Nevertheless, I had no heel slippage while running. The forefoot fits better as I am able to secure it but will require some time to adjust the laces.
In my regular size EU45 (45 2/3 in Adidas) or US11 the Boston 12 feels a little bit long so I could have gone for a half size down.
Ride
I bought the Boston 12 to replace my Saucony Endorphin Speed 2 on my workouts and long runs, so I had high expectations. I’ve done all types of training with them, from slow runs to workouts, long runs, and a 5K race. Unfortunately, I found out that the Boston 12 are not the super-trainer I was expecting it to be. Not even sure if I can call it a super-trainer.
For heel strikers, like me, the midsole is too firm for slower runs, so the Boston 12 is not fit for daily, easy runs. Perhaps if you are a heavy runner then you might be able to better activate the foam and Energy Rods in the slow runs, but light runners need to land harder to activate them. If you prefer soft foams, then forget the Boston 12.
If you are a forefoot striker, then you will benefit from the LightStrike Pro stack underfoot and you’ll find that the Boston 12 is softer, bouncier, and more enjoyable. Still, forefoot strikers will find softer options.
I got away with the uncomfortable upper in shorter runs, but on the long runs, I felt too much pressure from the laces and also felt the upper fabric rubbing my feet in specific zones. None of this prevents me from doing long runs with the Boston 12, but it’s preventing me from enjoying them as much.
Now, let’s talk about speed. These are the Boston after all.
Shifting the subject to speed, the Boston 12 reveals itself. It’s their purpose, why they were developed. Not for daily runs, not for easy long runs, but for speed.
When I raise my pace, my striking moves more to the forefoot, I get more of that fabulous LightStrike Pro and despite being a somewhat heavy shoe for speed, the Boston 12 are up to the task. I still don’t get the bounce feel that other performance shoes have, but the Boston 12 are propelling me forward, making my transitions faster. I don’t feel a pop from the Energy Rods, but they are definitely present, providing a great toe-off.
The Boston 12 needs to be running at 4:00 km/min (6:40 mi/min) or faster to show the best that it has for us. This is when I can really activate the foam and Energy Rods. Heavy runners should be able to activate the midsole at slower paces though.
Despite not being very comfortable for long runs, progression runs are great with the Boston 12. They can easily adapt to the different pace changes and when you reach the final stages of the progression run, you'll be glad to be on a shoe like the Boston 12.
Because I enjoyed so much doing speed work with the Boston 12, I decided to grab my Endorphin Speed 2 again and compare both rides. This was the moment I was surprised with the Boston 12.
First, I immediately felt that the Speed 2 were lighter, nimbler, more comfortable, and more unstable. Both shoes are for neutral runners and I don't have any issue while running with the Speed 2, but the Boston 12 almost feels like a stability shoe when compared to the Speed 2. The Endorphin Speed 2 also had more cushioning, more energy return, and more bounce!
But then I got it. I understood the Boston 12. Doing strides with the Boston 12 feels much better and quicker than with the Endorphin Speed 2. But don't take me wrong, it's all about the feeling and not the actual speed. I feel that I am running faster, and perhaps I am in short strides, but I don't believe that the Boston 12 are faster in a 5K or 10K race. I believe that both shoes will be identically fast.
Nevertheless, for workouts, I preferred the snappiness of the Boston 12 instead of the bounce of the Endorphin Speed 2.
Value
The Boston 12 retails for 160€ | $160. At this price, we have the Puma Deviate Nitro 2 and for 190€ | $170 we have the Saucony Endorphin Speed 3.
So, the price is within the expected range for a plated workout shoe, but in the end, I think that the Boston 12 are a hard sell. Unless you prefer a firmer ride and are more focused on speed training, the Speed 3 are a better deal. They cost just a little bit more, but they can do much more than the Boston 12.
Verdict
So, if you want one shoe to do it all, that shoe is not the Boston 12. But it will fit nicely in a two-shoe rotation paired with a comfortable workhorse like the Puma Velocity Nitro 2. Leave the Boston 12 for the speed work and races, and go with the Velocity for everything else.
If you want a 3-shoe rotation, then add a racer, like the Adios Pro 3.
Having the Velocity, you won't need a 4-shoe rotation, but I would add the Saucony Triumph 21 for the +25K long runs.
If you need help building your running shoe rotation, check out this post.
Drop me a line if you have any questions, and don't forget to follow the blog on social media and subscribe to receive a notification when I publish a new blog post.
If you're interested in buying the Adidas Boston 12, follow the links below:
- US: Road Runner Sports
- EU: Top4Running - Code "allaboutrunning" for an additional 5% discount.
- UK: SportsShoes.com | ProDirectSport.com
- Global: Amazon
These are affiliate links, meaning I get a commission if you decide to make a purchase through my links, at no cost to you. It helps out my blog so I can keep bringing new content.
Portuguese-speaking readers, I have this same content in video format here (video below). Visit my YouTube channel.
0 Comments