Men's Shoes Karhu

KARHU Fusion


The Karhu Fusion delivers unbeatable cushion and fast transitions to your everyday runs.

Built on top of Karhu’s unique AeroFoam midsole, the Fusion is lightweight and more temperature resistant than shoes built with EVA midsole foam. Maximum cushioning in the forefoot creates super-soft landings while an added propulsion unit energizes take-offs.

A shortened, 3/4-length Fulcrum embedded in the midiole of the Fusion concentrates cushioning toward the heel and midfoot, creating a responsive rocker that stabilizes each step and pushes you forward.

The upper is constructed from Karhu’s super-breathable, lightweight Ideal Knit mesh that supports your foot on top of the midsole for an all-around comfortable fit.

Karhu also created a high-volume option for wider feet. The Fusion HiVo provides a wide width for runners who need a little more space.

Tech Specs

Karhu Fusion Ortix 2021


8.8 oz (W) 10.5 oz (M)


6 mm




Everyday training, racing



What's New + -

While the nuts and bolts of the Karhu Fusion Ortix 2021 are the same as previous versions, the new edition is lighter with a sleeker upper to shed ounces. The AeroFoam midsole is as cushy as ever, but the adjusted Fulcrum and propulsion unit create a faster transition in this version than the previous models.

Who It's For + -

The Fusion Ortix 2021 is a neutral shoe that packs a punch when it comes to cushioning. Whether you’re looking for something comfy to walk in or need a shoe that can absorb impact over long miles, the Fusion Oritx 2021 is for you.

Why You'll Love It + -

Great for everyday training or road races, the Fusion Ortix 2021 is a versatile shoe that provides plush cushioning and quick transitions.

Reviews (2)

4.5 out of 5 stars.

4.5/5 on 2 total reviews

Jeffrey Verified Buyer
4 out of 5 stars.
My Karhu Fusion 2021 Running Shoes are Perfect!

Expert service and my new Karhu Fusion 2021 running shoes have healed the osteomyelitis in my 2nd toe. After seeing a podiatrist for my foot problem, I went to my local Fleet Feet shoe store for correct sizing. Fleet Feet's analysis showed my old shoes were all incorrect and that I needed a larger size. The wider toe box in the Karhu Fusion 2021 gave me the room that I needed; the larger size helped heal my toe infection. I wear them daily as I walk 5 miles in complete comfort on the hilly streets and walking trails nearby. My podiatrist has pronounced me completely healed, and my exercise proceeds uninterrupted as a result. A special shout-out to my FF salesman Malcolm East, former world class marathon runner here in Pittsburgh, for his expertise, is also made. Many thanks to Fleet Feet Sports for its invaluable service to me.

Steve Verified Buyer
5 out of 5 stars.
Best support I’ve had in years

I have slight pronation in my left foot. The fusion has provided exceptional stability and arch support along with perfect arch height. Best shoes I have had in years. Thanks Karhu!!

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