New research led by North Carolina State University has confirmed that 100% Merino wool base-layers offer unparalleled thermal comfort and performance benefits for athletes engaged in stop-go sports such as cycling, hiking, rock climbing and golf. The findings underscore Merino’s ability to manage body temperature and moisture across dynamic activity and rest periods, positioning it as the definitive natural performance fibre.

The four-year study, now published and peer-reviewed, introduced the concept of dynamic breathability - a measure of how well a fibre responds to real-time changes in heat and moisture. Merino wool emerged as the only fibre tested to maintain stable microclimate conditions during both exertion and recovery phases, offering athletes improved comfort and energy conservation.

Unlike synthetic performance garments that trap moisture or lead to after-chill, Merino’s dual-layer structure (hydrophilic on the inside, hydrophobic on the outside) allows it to absorb up to a third of its weight in moisture vapour without feeling wet. This helps regulate the critical next-to-skin microclimate, reducing the body’s need to work harder to stay at the optimal skin temperature of 35°C.

“Merino wool is no longer just a natural fibre choice - it’s a performance asset,” said John Roberts, Managing Director of The Woolmark Company. “Its structure responds in real time to the body’s needs, enabling athletes to stay within their comfort zone, even in the most unpredictable environments, he said”

Key findings from the study include:

- Merino wool buffered moisture 96% better than polyester, 45% better than cotton, and 26% better than viscose

- It was the only fibre to deliver consistent thermal regulation through activity and recovery

- It helped reduce the energy demands placed on the body during repeated exertion

These findings have already drawn attention from leading sportswear brands exploring natural fibre-based performance designs. As product developers look to marry sustainable practices with high performance, Merino wool offers a proven, science-backed solution.

Access the peer-reviewed papers here:

The Exothermic Effects of Textile Fibers during Changes in Environmental Humidity

A new approach to demonstrate the exothermic behaviour of textiles by using a thermal manakin

Clothing impact on post-exercise comfort: skin-clothing physiology in transient environment

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