Basic parameters:
• Weight: 423 g
• Drop: 10 mm
• Type: training
Upper and comfort
The UltraBoost 21 features a soft and flexible Primeknit upper, which wraps the foot well and provides decent ventilation. The soft heel counter deserves special mention—it minimizes the risk of chafing, even during longer runs. Unfortunately, a stiff plastic cage has been used in the midfoot area, which does improve foot hold but can cause pressure and discomfort, especially for people with wider feet.
Cushioning and running feel
The midsole consists of a thick layer of Boost foam, which provides very soft and comfortable cushioning. The UltraBoost 21 absorbs shocks perfectly, making it especially suitable for easy runs, recovery workouts, and everyday use. The high midsole and cushioning make every step very plush, but unfortunately, the shoe lacks dynamics and springiness at faster paces. The high weight is very noticeable during longer runs or when trying to speed up.
Stability
The UltraBoost 21 offers moderate stability thanks to its wide platform and stiff midfoot cage. The shoe holds the foot well during straight running, but the rigidity of the cage can limit natural movement and cause discomfort for people with high arches or wide feet. The soft heel counter increases comfort but does not affect stability.
Grip and durability
The outsole is made of Continental rubber, which is a huge advantage of this model. The tread provides excellent grip on both dry and wet surfaces, and the outsole’s durability is very high – even after hundreds of kilometers, wear is minimal.
Summary
The Adidas UltraBoost 21 is a training shoe for those who value maximum comfort, soft cushioning, and durability. The soft heel counter and Continental outsole are the biggest advantages of this model. Unfortunately, the stiff midfoot cage can cause discomfort, and the high weight means the shoe is not suitable for fast running or dynamic workouts. The UltraBoost 21 works best for easy runs, walks, and everyday use, especially for those who prefer soft shoes and do not expect much dynamism from them.
Final ratings:
• Comfort: 2/5
• Cushioning: 3/5
• Responsiveness: 1/5
• Grip: 4/5
• Durability: 4/5
Average rating: 3/5
Want to know my thoughts on other models?
Check out the section called Running Shoe Reviews, where I regularly publish detailed evaluations of running shoes.
