What is the best natural fabric for running?

Merino wool is widely considered the best natural fabric for running. It wicks sweat efficiently, regulates temperature across a wide range of conditions, and naturally resists odor — which means you can wear the same shirt for multiple runs between washes. Lightweight merino (around 150 g/m²) feels surprisingly thin and cool, nothing like the heavy wool sweaters most people imagine.

For warmer climates, bamboo lyocell blends and lightweight organic cotton-elastane jerseys are strong alternatives. They offer a cooler hand feel and dry reasonably quickly after a sweaty session. The important thing is to avoid heavy, untreated pure cotton for long-distance or high-intensity running, as it absorbs too much water and can cause chafing.

ONDU features running-ready tops and shorts from brands like Icebreaker, Allbirds, and Vuori that prove natural fibers can keep pace with your training.