What is an Upper?

The Upper is everything on a running shoe that sits above the sole. Its primary job is to secure your foot comfortably to the midsole, providing a "lockdown" feel without being too restrictive.

Common Materials

1. Engineered Mesh: The standard for most modern shoes. It’s breathable, lightweight, and can be woven tighter in some areas for support and looser in others for ventilation.
2. Knit: A sock-like material (e.g., Nike Flyknit) that offers a very adaptive, snug fit but often provides less structural support than mesh.
3. Overlays: Plastic or synthetic strips printed onto the upper to provide extra structure and durability.

Key Features of a Good Upper

• Breathability: Prevents feet from overheating and reduces the risk of blisters.
• Lockdown: Ensures the foot doesn't slide around inside the shoe, especially on turns.
• Heel Counter: The stiff cup at the back of the upper that supports the heel and prevents it from slipping out.
• Gusseted Tongue: A tongue that is attached to the sides of the shoe to prevent it from sliding and to keep debris out.

A great midsole makes a shoe fast, but a bad upper makes it unwearable.