Harāra Running Underpants Prototype 005.1

After countless tests with fabric compositions, knitting techniques, and weave structures, we believe we’ve found the one! These trunk-shaped performance undies are engineered for middle- and long-distance athletes, where every marginal gain counts.

Made to handle any distance, surface, or heat—from long trail runs to hard intervals on the track. Whether you're cruising through a tempo session on the road, logging easy miles on a trail, or racing an 800m on the track, these underpants are built to perform in warm to hot conditions.

We curated a custom ice silk fabric and stripped the design back to its essential elements, maintaining function, comfort, and safety—all while weighing just 33 grams dry and 59 grams wet1.

How did we do it? Our fabric is just 0.27mm thin. Its composition includes built-in elasticity, enhanced further by an ultra-fine knit construction for added stretch and flexibility. This allowed us to reduce thickness without compromising coverage, even when wet.

The inherent stretch also enabled us to slim down the waistband without sacrificing support. We shaped the pouch for extra comfort and reduced chafing, eliminating the need for top padding. Flatlock stitching helped us shave off a couple more grams, and minimise friction.

The result? Ultra-lightweight, cool, breathable, and non-pilling performance underwear—purpose-built for athletes chasing every possible edge.


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1 Reference size M