By Ben Stockton
When Under Armour first came onto the cleat/athletic footwear scene, they utilized standard EVA compounds (the foam found in most midsoles) of varying densities under titles such as ArmourBound and ArmourLastic in their midsoles. These early running and training models shared clunky midsoles and were rarely adopted by the masses. 2010 rolled around, and after a failed attempt to enter the footwear industry, Under Armour unveiled their crown jewel, Micro G. Debuting originally in running, basketball, and training shoes, Micro G drew critical acclaim from many performance reviewers, prominently at Weartesters.com. In 2011, Micro G made the transition to the cleat world. The foam formed a consistent and unrivaled level of cushioning desired by athletes across the sporting world.
Micro G is a unique polymer combining traditional EVA with rubber to provide elasticity and prevent the bottoming out common to other foams, notably Lunarlon (Nike’s proprietary foam). In many early shoes featuring Micro G, the foam’s presence is denoted by an array of circular dots on the midsole. These dots serve mostly an aesthetic purpose, but also function as compression grooves. Compression grooves allow the foam and midsole to compress more easily and give the wearer a softer ride. From the first Micro G shoes up until today, many contain a Micro G insole on top of the Micro G midsole. The Micro G insoles are often bright orange and feel springy, dense, and smooth to the touch. Unfortunately, many of the cleats opt instead for a 4D-Foam insole which does a fantastic job of molding to the foot, but an equally poor job of cushioning as they are very thin once molded. However, the 4D-Foam insoles are removable and can be swapped out for a plush Micro G version which also molds to the foot.
Many athletes appreciate Micro G not only for its superb cushioning properties but also for its longevity. The foam responds quite efficiently to every footstrike, never leaving the wearer with a mushy and impeded sensation. It should be noted that footwear CANNOT make an athlete faster, but it can minimize distractions through comfort and responsiveness. Micro G also provides exceptional impact protection (for a foam, air based cushions are nearly always better). As with many foams (Boost excluded), the impact protection is not immediately noticeable while active, but after activity, one’s back and joints don’t ache. Ride smoothness or transition is also a strength for Micro G. The unique compression properties of Micro G allow the designers of UA’s cleats to develop midsoles thinner than the competitions’ and often more cushioned. The single-piece, low-profile midsole is directly responsible for the splendidly smooth transition. When not active Micro G becomes a soft mattress under foot. Easily, it is one of the most comfortable off-field options.
On the field, many ballplayers enjoy the footwear miracle that is Micro G. Players ranging from Billy Hamilton and Byron Buxton to Yasmani Grandal and Buster Posey to Jose Fernandez and Chris Archer wear cleats featuring Micro G. All of these guys demand different things from their cleats and their cushioning. The universal appreciation of Micro G truly speaks to the versatility of the foam and the comfort it provides. Speed-driven players, such as Hamilton and Buxton who need responsiveness to explode from base to base on steals and to leg out extra bases, get what they need. Catchers, who need something distraction-free and comfortable on their feet while they take a beating behind the dish, get what they need. Pitchers, who drive off of their feet and land hard on the mound, so too get what they need. Other guys who wear Micro G cleats include Bryce Harper (Spine-based cleats), Joc Pederson, Dee Gordon, J.D. Martinez, and Brandon Phillips.
Some cleats currently available with Micro G: UA Deception Low/Mid, UA Yard Low/Mid, UA Spine ST Low/High, UA Heater ST (note that the TPU version uses ArmourBound and a different upper construction).
Some trainers currently available with Micro G: UA Decepetion XT, UA Yard Low Trainer, UA Speedform Phenom, UA Highlight (not to be confused with the football cleat), UA Sting II, UA Speedform Apollo Original/Vent/XC, UA Scorpio.
(Footnote: i) Charged Foam is not the same as Micro G and will be covered at a later date. ii) Spine tech encases Micro G in an EVA shell and will also be covered at a later date.)