Type: Road

Weight: 267g (size UK 8.5)

Drop: 7mm

Designed to give runners that 'race day' feeling on mid-to-long-distance training runs, the 12th iteration of the Adidas Adizero Boston is a lightweight and fast training shoe, filled with a whole host of high-performance tech.

The upper is made from a breathable engineered mesh, while the stiff midsole includes glass-fibre energy rods (which help to limit energy loss underfoot in a similar way to carbon-fibre rods). The Boston 12 also has a layered midsole consisting of Adidas’ high-performance foam, 'lightstrike pro', and the all-new lightstrike 2.0, for a cushioned (ish) yet dynamic ride.

So if you’re a fan of racing in the Adios Pro 3, then this might be the perfect training companion for you...

The Adizero Boston range is designed for runners who prioritise speed and responsiveness. Previously known for being a little more on the 'firm' side, the Boston 12 was tested across 19 sessions with Adidas professional athletes in Kenya to find out exactly how this shoe could be reworked into a better version.

I found the Adizero Boston 10 way too firm to run in, and despite the fact they looked great, people kept telling me they needed 50 miles or so to 'break them in'. Now, I’m not the sort of runner who's willing to run in a shoe that doesn’t feel right for 50 miles, so unfortunately they were cast aside pretty quickly. And, I know I’m not alone when I say that not many people raved about the Boston 10s.

The Adizero Boston 11 had a bit of a change to the upper and ankle, but still looked – and felt – rather similar to the 10s; narrow and firm. So, for running in, I wasn’t a fan of the 11s either.

The 12, however, seems like it’s had quite the transformation, feeling much softer underfoot in comparison with previous iterations. This is mainly thanks to the lightstrike 2.0 material in the heel section.

Since the Boston has always been the kind of shoe that you need to wear in before you start to feel the benefits (because it's known for feeling very firm), I was pleasantly surprised when I slipped the 12s on and didn’t feel like I was slapping the ground hard and getting no bounce back.

In fact, they reminded me slightly of the Adizero Adios Pro 3s. Of course, the Boston 12 doesn’t feel nearly as fast as the Adios Pro 3 to run in – it’s not a race-day shoe, after all. But Adidas has clearly taken some of that exciting tech from the Adios Pro 3 and put it into a shoe that you can use every day for training in.

I tend to size up half a size (in comparison to my normal day-to-day shoes) in Adidas running shoes, so I’d say these fit pretty true to size. They are on the narrower side, so if you do have really wide feet, you may struggle to actually get your foot in these.

The tongue of the Boston 12 has also been tweaked – I’m not 100% sure I’m a fan – so when you slide your foot in, it does take a little adjusting to get that locked-in feeling. The upper feels supportive, not restrictive, and my heel feels locked down.

If you are currently training for a fast half marathon or marathon – and you love racing in the Adios Pro 3 – then this performance-centred training shoe really shines at tempo-paced workouts. Yes, the Boston 12 is still a firm ride, but it’s a drastic improvement in comparison to the Boston 10 and 11. Of course, if you prefer softer, more cushioned shoes there’s a chance you might not vibe with the Boston 12s at all, in which case the Adidas Ultraboost SL might be the better option here. But, overall, we thought the 12 was a really nice update and the perfect companion shoe to the Pro 3.