New and improved! The updated version of this product is now available.
KARHU Fusion 4.0
Women's
Running
Shoes
Men's
original price $160 sale/discounted price $120
Fleet Feet Reviewed
Features
Stylish and propulsive, you will be excited to lace up the Karhu Fusion 4.0.
Get ready for quick, cushioned runs, this shoe is streamlined to work whether you are running long distance or kicking it up a notch with some tempo work. Our testers loved the smooth and snappy feel of their runs in our Karhu Fusion 4.0 review. Plus, with its new knit upper, it looks great for casual wear as well.
Details:
- Upper: The stylish Ideal Knit upper feels as good as it looks with a snug, streamlined fit. Featuring Karhu’s signature M-lock midfoot fit, you will feel secure as you rock your runs.
- Midsole: The nitrogen-infused AeroFoam cushioning is responsive and snappy and when combined with Karhu’s Fulcrum technology, creates a swift and efficient underfoot feel.
Tech Specs
KARHU Fusion 4.0
Weight |
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Heel-to-toe drop |
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Stack height (heel/forefoot) |
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Surface |
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Ride | 2/5 on the Firm to Plush Scale |
Cushioning | 3/5 on the Minimum to Maximum Scale |
Energy | 3/5 on the Relaxed to Propulsive Scale |
Category | neutral |
What’s New
Karhu updated the Fusion 4.0 with a new look and feel. A brand new Ideal Knit upper gives you plenty of style, while still fitting and feeling great during the run. Karhu revamped the midsole with the nitrogen-infused AeroFoam cushioning to give you a plush and propulsive ride.
Who It’s Best For
The Karhu Fusion 4.0 is a snappy and propulsive neutral ride that’s ideal for those with a high, rigid arch and performs well whether you are doing long runs or tempo workouts.
Why You’ll Love It
You will love how efficient and propulsive running feels in the Karhu Fusion 4.0.
Read More in Our Karhu Fusion 4.0 Review

Karhu Fusion 4.0 Review
In the Karhu lineup, the Fusion is positioned as a propulsive option. But can the Fusion 4.0 live up to its energetic reputation?
Reviews
Star Rating is 5 / 5
My new favorites
I had never heard of these shoes before. After trying them on, I was sold. The fit was perfect and they required no break in time. I used to wear Brooks Ghost. Will be buying Karhu now.