On Cloudmonster 3 Hyper LS Review: The Lightest Super-Trainer Yet
What to Look For
Super-trainers have transformed daily running for triathletes — and On’s Cloudmonster line sits at the forefront of that revolution. The Cloudmonster 3 Hyper LS (LightSpray) launches in March 2026 as On’s most advanced daily trainer yet, combining a towering foam stack with a featherlight upper that redefines what a high-cushion shoe can weigh.
Key Features to Consider
- 45mm heel stack height — Towers over the standard Cloudmonster 3 Hyper’s 39.5mm, delivering a significantly more cushioned and propulsive ride for long-run days and recovery sessions.
- LightSpray upper — Originally developed for On’s elite racing shoes, the LightSpray process creates an ultralight, seamless upper that saves around 50 grams versus traditional construction while maintaining excellent foot hold.
- Full-length PEBA foam layer — Upgraded over the original Cloudmonster Hyper, this top layer of PEBA foam increases energy return and creates a bouncier, more responsive underfoot feel across the entire foot strike.
- Sub-7oz total weight — Remarkable for a max-stack trainer. The weight saving makes it viable for faster long runs and even triathlon run legs where every gram counts.
Our Top Picks
Best Overall: On Cloudmonster 3 Hyper LS
Launching March 2026 at around £210, the Cloudmonster 3 Hyper LS is the shoe to watch for triathletes who want a do-everything trainer that can handle 20-mile long runs, easy brick run sessions, and race-pace tempo work without feeling sluggish. The LightSpray upper fits the foot precisely, reducing slippage on downhills — a common problem in traditional foam-heavy trainers. This is On’s most complete running shoe to date.
Shop On Cloudmonster 2 on Amazon (current model)
Best Value: On Cloudmonster 2
With the LS variant arriving in March, the Cloudmonster 2 will see price reductions across major retailers. If you’re happy without the LightSpray upper and can wait for the discount season, the Cloudmonster 2 delivers 95% of the experience at a substantially lower price. It’s ideal for beginner and intermediate triathletes building their weekly run volume.
Best Premium Alternative: ASICS Superblast 3
Also launching in early March 2026, the ASICS Superblast 3 at £210 is the On LS’s closest rival in the super-trainer category. Where the LS prioritises weight reduction, the Superblast 3’s FF Leap foam prioritises pure energy return for faster long-run efforts. Triathletes coming from an ASICS background will feel immediately at home.
Buying Tips
- The LightSpray upper runs true to size but offers a snugger fit than traditional On uppers — if you have wide feet, try before you buy or order from a retailer with free returns.
- Super-trainers like the Cloudmonster LS are ideal for easy and moderate runs but not designed as race shoes. Keep a race-day flat (like the On Cloudboom Strike LS) in your rotation for race day.
- For UK buyers, the LS will be available directly from On and through specialist retailers from March 2026 — sign up to On’s newsletter to get notified on launch day.
Care and Maintenance
The LightSpray upper is delicate compared to traditional mesh — avoid machine washing. Instead, wipe clean with a damp cloth after wet runs. Rotate with a second pair to extend foam life, and replace when the foam stack shows visible compression on one side (typically after 500–600km of use).
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