The fleece is the heart of any effective outdoor layering system, providing essential insulation that traps body heat while remaining breathable enough to prevent overheating. This versatile mid-layer is what you'll rely on for warmth and functionality across a huge range of activities and conditions, from a lightweight fleece jacket on a cool summer evening to a heavyweight full-zip fleece under a shell in the depths of winter.
The key to a fleece's performance is its material. Classic synthetic fleece is highly efficient, holding less than 1% of its weight in water, which allows it to dry quickly and continue insulating even when damp. The structure of the fleece—whether it’s a high-loft, fluffy fabric or a denser, gridded pattern—determines its warmth-to-weight ratio and breathability. Lighter microfleece options are ideal for high-output pursuits like running or climbing, where managing moisture is just as important as staying warm.
Modern fleeces also incorporate smart features that enhance their function. Stretch panels can improve mobility, wind-resistant overlays add protection, and thumb loops help to seal out drafts. Whether you need a simple fleece jumper for everyday use or a technical, feature-rich layer for the mountains, choosing the right fleece will significantly improve your comfort and performance outdoors.
