Energy was just energy until energy met Ultraboost 21.

Prototype after prototype. Innovation after innovation. Testing after testing. Meet us in the hot pursuit of the pinnacle harmonization of weight, cushioning, and responsiveness. Ultraboost 21. Say hello to incredible energy return.

adidas LEP
The new Torsion System provides a 15% increase in forefoot bending stiffness for a more responsive run.
Incredible Energy Return
6% more Boost capsules ready to explode with energy in each step.
Primeblue
This product is made with Primeblue, a high-performance recycled material made in part with Parley Ocean Plastic. 50% of the upper is textile, 75% of the textile is Primeblue yarn. No virgin polyester.

Features:

• Sock-like fit
• Lace closure
• adidas Primeknit upper
• Textile lining
• Supportive heel counter
• Boost midsole
• Weight: 340 g
• Midsole drop: 10 mm (heel 30.5 mm / forefoot 20.5 mm)
• Stretchweb outsole with Continental? Rubber
• Primeblue