adidas Unisex-Child Ultraboost 21 Running Shoe – Superior Comfort and Support for Young Athletes


Give your child the gift of superior comfort and support with the adidas Unisex-Child Ultraboost 21 Running Shoe. Designed for junior athletes, this advanced running shoe provides an energized, responsive ride to help them reach their goals.

Primeblue Knit Upper for Flexible Support

The Ultraboost 21 features an upper made from adidas’ innovative Primeblue material. This unique yarn contains Parley Ocean Plastic, made from recycled plastic waste gathered on beaches and in coastal communities before it reaches the ocean. By using Primeblue, adidas helps keep plastic waste from polluting our seas.

But Primeblue isn’t just eco-friendly, it also provides a flexible, sock-like fit thatmoves naturally with your child’s foot. Strategic zones of compression and stretch support your child’s foot during lateral movements while allowing full freedom of motion. The breathable Primeblue knit upper fits like a sock, providing a locked-in feel for confident strides.

Lace Closure and S-Curve Heel for Secure Fit

To complement the flexible upper, this running shoe features a lace closure system that lets you customize the fit. Lace up the Ultraboost 21 snugly for a secure, supportive feel that won’t slip during sprints and lateral drills. The laces connect to a flat burrito tongue, preventing tongue slide while also reducing pressure on the top of the foot.

The S-curve heel shape cups the back of the foot, keeping it stable laterally without uncomfortable pinching or rubbing. This ergonomic heel design enhances support and lockdown, giving young athletes the confidence to make quick cuts and fast directional changes.

Boost Midsole for Soft, Energy-Returning Cushion

The real magic of the Ultraboost 21 comes from its Boost midsole. Made from thermoplastic polyurethane (TPU), the proprietary Boost foam compresses softly underfoot to absorb impact. But unlike traditional foam, it springs back instantly, returning the energy put into each step to propel your child forward. The result is an ultra-cushioned feel that keeps their feet feeling fresh mile after mile.

Embedded in the Boost midsole is a TORSION SYSTEM between the heel and forefoot to provide support and stability. This thermoplastic unit allows the forefoot and heel to move independently while preventing excess twisting for a smoother, more natural stride.

Stretchweb Rubber Outsole Flexes Naturally

On the bottom, a flexible Stretchweb rubber outsole complements the movable Primeblue upper. The adaptive Stretchweb contours to the shape of the foot, expanding naturally to provide a barefoot-like feel. Deep continental rubber on the outsole enhances traction on diverse surfaces, allowing for stable footing when sprinting on grass and gripping pavement when training on roads.

Additional Features:

  • Textile lining for next-to-foot comfort
  • Molded sockliner hugs the contours of the foot for support
  • Geometric heel frame adds stability and support
  • Tongue constructed to avoid top-of-foot pressure
  • Durable Adiwear outsole in high wear areas for long-lasting performance

Built for Young Athletes

Help your child reach new levels of performance in the adidas Ultraboost 21. This running shoe combines technologies like Primeblue knit, Boost cushioning, and a flexible outsole to provide the ultimate in energy return, comfort, and adaptability. The result is a responsive feel that helps young athletes of all abilities run their fastest and furthest. Order a pair today!


  • Weight: 8.1oz (size 7)
  • Drop: 10mm (heel is 10mm higher than forefoot)
  • Shaft height: Low top from arch
  • Achilles padding to prevent rubbing
  • Aggressive heel curve for natural foot position
  • Moulded EVA midsole for lightweight cushioning
  • Rubber outsole for durability and traction


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