adidas Lady Sonic Boost Running Shoes Boost Foam Midsole - Every step becomes charged as the Boost midsole absorbs some of the energy from your footstrike and charges it into forward momentum. Boost Foam - Located in high impact zones at the heel and forefoot. AdiWear Durable Outsole - Outsole rubber which is highly durable and offers excellent damage resistance. Welded Overlay - Enhances the fit and strength of the upper and helps decrease the weight of the upper. External Heel Counter - For a snug heel fit and comfort in motion with enhanced support and stability.