The Brooks Glycerin Stealthfit 21 Review & Lab Test: Shop Men’S & Women’S Models of 2026

The Brooks Glycerin StealthFit 21 is a lightweight running shoe designed for daily use. Its notable weight reduction enhances performance, making it ideal for runners seeking a comfortable fit.

With a snug, sock-like upper, the Brooks Glycerin StealthFit 21 offers a secure feel. Although it has a slight compromise on breathability and cushioning, these factors are supported by lab data indicating significant durability across various terrains.

This shoe is particularly suited for those prioritizing comfort during their runs. The design ensures a stable platform, translating to improved real-world performance for dedicated runners.


Pros

  • Durable outsole
  • Sock-like tongue
  • Significant weight reduction
  • Comfortable fit
  • Great for long runs
  • Improved heel counter
  • Supercritical foam

Cons

  • Needs more breathability
  • Lacks energy return

Key Features

  • Supreme Softness: Enhanced with nitrogen-infused DNA LOFT v3 cushioning for an exceptionally soft and responsive ride.
  • Secure, Adaptable Fit: The updated flat knit upper with Stealthfit construction provides a seamless structure that adapts to your foot's movements.
  • Smooth, Stable Transitions: A broad platform stabilizes your foot, promoting fluid heel-to-toe transitions.
  • Breathability: The flat knit upper ensures maximum breathability, keeping your feet cool during runs.

Specifications

  • Origin: Imported
  • Sole Material: Rubber
  • Outer Material: Nylon
  • Inner Material: Nylon, Foam

Brooks Glycerin Stealthfit 21 Review & Lab Test: Shop Men’S & Women’S Models – Price, Ratings, Reviews & Sales Insights

Brooks Glycerin StealthFit 21 Mizuno Wave Sky 8 Adidas Ultraboost 5 On Cloudeclipse
Price $160 $170 $180 $180
Pace Daily running Daily running Daily running Daily running
Arch support Neutral Neutral Neutral Neutral
Weight lab Weight brand 9.1 oz / 257g 9.6 oz / 271g 10.3 oz / 292g 9.6 oz / 272g
Drop lab Drop brand 10.5 mm 10.0 mm 10.6 mm 9.4 mm
Strike pattern Heel Heel Heel Heel
Size True to size True to size True to size True to size
Midsole softness Balanced Soft Soft Balanced
Difference in midsole softness in cold Normal Normal Small Small
Toebox durability Decent Good Decent Decent
Heel padding durability Decent Good Good Bad
Outsole durability Good Bad Good Good
Breathability Warm Moderate Breathable Moderate
Width / fit Medium Medium Wide Medium
Toebox width Medium Medium Wide Medium
Stiffness Moderate Moderate Stiff Stiff
Torsional rigidity Moderate Moderate Stiff Stiff
Heel counter stiffness Moderate Moderate Moderate Moderate
Rocker
Heel lab Heel brand 36.9 mm 40.7 mm 35.2 mm 39.9 mm
Forefoot lab Forefoot brand 26.4 mm 30.7 mm 24.6 mm 30.5 mm
Widths available Normal Normal Narrow Normal
Orthotic friendly
Season All seasons All seasons Summer All seasons
Removable insole
Ranking Bottom 36% Top 8% Top 14% Top 11%
Popularity Top 40% Bottom 43% Top 47% Bottom 35%