What Our Gearhead(R) Experts Are Saying:"I ran my last 50K in the Cloudultra Pro, and it felt dialed the whole time-especially through technical descents. The Helion HF foam gives crazy energy return without sacrificing ground feel, and the Missiongrip outsole held up in everything from loose gravel to wet alpine rock. The zoned upper breathes better than most ultras I've worn, and the rocker just keeps you rolling forward. It's a race-day-ready shoe for serious distance."When every ounce of energy matters and every step counts, we reach for the On Cloudultra Pro Trail Running Shoe. Built for ultra-distance endurance and tested on the rugged trails of the Alps, this elite-level trail shoe blends On's most advanced cushioning, traction, and support systems to help us move further-and faster. The dual-layer Helion(TM) HF midsole offers responsive rebound over miles of elevation gain and loss, while the Speedboard(R) delivers torsional stability and energy return through every phase of the gait cycle. Its engineered rocker geometry keeps transitions smooth, even deep into long efforts. The zoned Leno weave upper dries quickly and adds precise support, while an updated Missiongrip(TM) outsole with finely tuned lug geometry ensures relentless traction across all-terrain conditions. When we're chasing PRs or simply pushing our distance ceiling, the Cloudultra Pro keeps us locked in and moving forward.