Update 2/28/2013: I took the Boost out for a first run today. The upper is snug and feels great. No hot spots especially around my big toe which isn't liking anything but a wide shoe these days. The Boost is narrower in the forefoot than what I have been running in but no issues. It is fairly stiff in forefoot flex.
The "magic" Boost material is very cushiony especially at heel and at slow speeds, almost Hoka soft, but no sensation of sinking away into a pillow. Not much noticeable energy rebound just a very comfortable ride. A great shoe for long slow runs.
At speed they feel completely different. I can't say I feel a distinct rebound in the forefoot but I do sense that I may be turning over a bit faster. The feeling is firm but no harsh. See below my commentary about the Torsion System. Not nearly enough data but I ran a 1. 4 mile Strava segment 8 seconds faster than earlier this week with about the same perceived effort. Wish the heel was a bit lower.
Took a chance as I had only run in them once before and ran the Boosts in my first race of 2013, the Black Cat 20 miler in Salem, MA. Sensational. Ran the pre Boston tune up pace I wanted to and walked away from the race tired but not sore. Easy on the legs and responsive, a rare combination. Very good on downhills. Even towards the end when I was tired the shoes never felt sloppy. No blisters or issues with my troublesome big toe so the upper, while snug, does stretch just enough.
180 miles in the Boost. Except for a couple runs in the very fine Pearl Izumi N1 Trail all of my running in March has been in the Boost. Great day in day out leg freshness no matter what I throw at them. Almost no wear at all on the outsole. Snug upper should be thought of as a tight fitting sock and not as a shoe upper as that what it really is. No blisters, no problems with my troublesome big toe which anything other than a wide Altra Torin seemed to cause pain with in February and January. A bit firmer than when they were new and this is a good thing. I will be wearing them at Boston!
Update: While my Boston time was slow my feet and legs were happy in the Boost. For the first time in a marathon no blisters whatsoever.
Update 7/1/2013: Now have close to 300 miles on the Boost. Midsole has not collapsed. Upper almost like new and over time has stretched to my foot. The outsole is showing most wear in the toe off area.
Runners have been buzzing about the claimed energy return properties of the Boost midsole, a steamed under pressure molding and expanding of thousands of bits of TPU into a matrix of irregular shaped shapes. All other midsoles are made of EVA, either blown or molded, so Adidas use of TPU is different and the claim is that they provide superior energy return to EVA. Runner's World did some mechanical testing of the material which confirmed it had the best energy return of the 800 shoes they have tested. TPU is also not as sensitive to temperature differences, the brick midsole when its cold. I did my usual finger test of midsole firmness and find the material to be very soft indeed, softer in my test than even the very soft Hokas. Interestingly they feel more elastic; namely when pressed the material wants to pop back out. Indication of the energy return? We'll see..
Seeing how soft they were I thought they might feel mushy and "Hoka like", pillowy or unstable walking around the house. They do not. The other parts of the midsole and outer sole might explain.
|Adidas Energy Boost Construction|
|Adidas Boost Outsole|
|Adidas Energy Boost|
The upper feels outstanding. No seams at the toe which is a bit low and narrow in volume compared to what I have been running in lately, Altra Torins with their wide toe boxes. This said the Techfit material, which is not a mesh but more like a softshell material stretches just enough to make them super comfortable with the foot well held. They fit me true to size, may be a 1/4 size small.
Disclosure: I purchased the Energy Boost.