Boost-er!

I hate waking up early, especially when I've had a late night. But spring is here and so is the warm sun, which means the more time I spent under the sheets, the worse it was going to be when I ran my 5k this morning. But I still managed around four extra minutes of shut-eye before I limped out of my bed, splashed some cold water on my face, got into my running shorts and singlet, grabbed a bottle of Gatorade and slipped into a pair of - you guessed it, adidas Boost.

It's been a while since I last reviewed a pair of running shoes, and coincidentally a lot of new running shoe launches happen in spring, so I thought this was good a chance as any to write a new running shoe review. I first noticed the Adidas Boost when I was passing by a adidas store and initially I thought it was a one of the Bounce variants, given the similar aesthetic of the heel cushioning system. Before I saw the Boost, I had checked out the new 2009 Megabounce, but I decided against reviewing them as the shoe was built on same old 2008 Bounce sole unit and hence there was little difference in how the shoe worked. A few days later I managed to try on the new Boost in the store and found out that it was markedly different from the Bounce, so I got home a pair for a in-depth review.

So just how different is the Boost from the other 'mechanically' cushioned shoes there on the store shelves? A lot of brands boast of similar cushioning with shock absorbing struts, and the concept has been almost done to death with countless iterations. A few good examples would include the Nike Shox, Puma Spider Cell Max, the New Balance NB Zip, the Mizuno wave and adidas's own Bounce system. Except for the Nike Shox which uses polyurethane columns or air bags (like in the Nike Shox Experience), all other technologies use flexible thermoplastic units to construct their cushioning units. Thermoplastic urethane seems to the material of choice when it comes to making mechanical cushioning units since it offers advantages like a longer life and resistance to deshaping, unlike traditional molded foam. But such durability comes at a price - weight. Most of the existing thermoplastic based cushioning platforms are heavy; the Megabounce which I reviewed last year crossed the 400gm barrier, and Puma shoes which use the Spider Cell Max system would probably weigh more. But the adidas Boost seems to have partly addressed the weight issue, and we'll see how and why.

The Puma Spider Cell Max cushioning system: The heel unit is 100% thermoplastic urethane (TPU). And heavy.

Mizuno Wave cushioning system: Wave like TPU structure lies sandwiched between the midsole foam.

New Balance NB Zip cushioning system: TPU strut construction in a forward biased design.

2009 adidas Boost: Is the Boost the odd one out in the happy mech-tech fraternity? We'll find out soon enough...

At first glance, the adidas Boost seems to be a cross between the New Balance NB Zip and the Mizuno Wave, but from a performance perspective, a little bit of German ingenuity has built in an element of differentiation into the Boost. While technologies like the NB Zip, Bounce and the Spider Cell Max use 100% TPU, the engineers at adidas have slipped in a foam core inside the Boost unit. This allows the Boost to shave off previous milligrams off its gross shoe weight and end up at a respectable weight of 370 grams for a half pair of US 10.5.

The Boost: An injection molded EVA foam core (in grey) sits inside the Boost TPU cage. The foam is the same material which is used in the rest of the midsole.

The core: The foam in the Boost unit peeps out of the window in the outsole. The rubber outsole uses adiwear, adidas's proprietary outsole formulation.

Besides minimising weight, the foam pillar in the centre adds ride consistency, as was evident during the 5k wear test. Since the remainder of the midsole is injection molded EVA foam (same material as the Boost core), the heel to toe transition during footstrike is smooth as the foot lands on the foam core (surrounded by the Boost TPU cage) and then moves forward towards the midfoot and finally toe off for the next gait cycle. The upper edges of the structure curves outwards and cups your heel, so the risk of the foot shifting on the Boost unit is eliminated.

Cup-sole: The upper edges of the Boost units curve upwards, which results in a cup like function, holding your heel in place.

While the Boost unit does its job with a fair degree of confidence, there are some let downs in the overall construction of the shoe. For a shoe which is positioned as a cushioned running shoe, the lack of an EVA strobel and a molded sockliner comes as a surprise and disappointment. The sockliner/insole uses a fabric covered, die-cut EVA foam sheet instead of a compression molded EVA insole. Not something which you would expect in a shoe which costs Rs.5000 in India and around $85 in the United States. Similar sentiment for the lack of an EVA strobel which would have made the ride so much better and cushioned. Last year, I reviewed the Puma Complete Phasis, and that shoe had both these features at a price lesser than the Boost.

The Boost loses brownie points: Die cut EVA sheet instead of molded insole and a plain fabric strobel instead of EVA? Not expected of a shoe which costs INR 5000. The tongue padding could have also been much better.

The Boost uses a combination of synthetic leather and air/sandwich mesh on its upper, and these materials do their job well. The air mesh adds breathability plus a snug feel, and the synthetic leather overlays and the welded three stripes on the side keep the foot secured while running. The collar area is well padded; it kept my heel secured during the duration of the 5k wear test, and I did not experience any heel slippage. The collar lining material could have used an upgrade, though. The collar lining seemed to be using the same kind of fabric used on cheaper adidas shoes and something softer would have been great. The tongue padding could have also used a little more foam - the tongue felt like as if it was taken off a racing flat, which is not the right thing to do when you are building a neutral, cushioned mileage cruncher.

The upper aesthetics of the adidas Boost offers some compensation for some of its shortcomings. The black-gunmetal-silver mesh and synthetic leather combo is a pleasant contrast to the deep red Boost unit, and red welded three stripes and the Boost logo on the tongue adds value. The upper uses three different kinds of synthetic leather textures, and one of them has a pearlized, glossy texture which looks and feels premium. The Boost unit is detail heavy, so the red and metallic silver high frequency welds on the three stripes brings in a color and detail balance. One of the other things I liked about the Boost heel unit is that it seems to blend in with the midsole well and the design is not in-your-face kind, which is typical of similar mech-tech cushioning systems in the market.

Aesthetic boost: The shoe uses premium looking material on its upper, and the black/Silver upper sets a lovely contrast with the red Boost heel unit.

Three stripes: The red and silver stripes are welded on to the synthetic leather underlays, and provides much needed color and texture balance.

Boost: adidas's new Boost logo, welded on to the top of the tongue.

Overall, the Boost is a shoe which performs respectively though there are a few areas which could have been better. But the new cushioning system seems to work, the upper looks premium and the shoe fits well. A Rs.5000 price tag is around Rs.500 more than what it should have been; the rupee equivalent of $85 would have been the right price, which in these troubled times is still around Rs.4400...