Vibram Five Fingers KSO - Keep Stuff Out - Toe Shoes

The Vibram Five Fingers KSO (KSO stands for "Keep Stuff Out") has been one of the most popular models of Vibram Five Fingers to date (Jump to posts on the KSO below!). It's closed top design sets it apart from the open-topped Classic and the open- and strap-topped Sprint. Some might argue the KSO put "Toe shoes" on the map due to it's popularity among runners. Like all Vibram Five Fingers models, the KSO has five separated toe compartments for each toe that allow the foot to splay on contact with the ground.

The Five Fingers KSO has no arch support and a minimal amount of cushioning or padding — it is slightly thicker than the Classic and Sprint which have zero insole (the KSO has a 2mm EVA insole). Many, many minimalist runners "cut their teeth" with the KSO — running 5KS, half-marathons, full marathons, and even ultramarathons in the KSO. That said, the KSO is also a favorite for exercise, casual wear with jeans (or shorts), and also for travel.

Model specifics

Here are the technical specifications of the Vibram Five Fingers KSO straight from Vibram:

Featuring a thin, abrasion-resistant stretch nylon and breathable mesh upper that wraps your entire forefoot to "Keep Stuff Out." A single hook-and-loop closure helps secure the fit. A non-marking 3.5mm Vibram TC1 performance rubber sole is razor-siped for a sure grip, and a 2mm EVA insole enhances plating protection and comfort.

KSO IS BEST FOR: Running, Light Trekking, Climbing/Bouldering, Fitness, After Sport, Water Sports, Yoga/Pilates & Travel

The standout features of the KSO include:

  • Closed top providing a fairly tight "seal" around the ankle. The KSO manages to "keep stuff out" by way of this seal leaves it looking somewhat like an ankle sock.
  • The KSO has a 2mm insole, which reduces "barefoot feel" as compared to the Classic or Sprint. Many users don't notice this small amount of cushioning. Some find it more comfortable for more varied surfaces such as trails.
  • The KSO is the most popular model for men!

Sizing and fit

If you've never sized your foot for Vibram Five Fingers, you need to consult the Vibram Five Fingers sizing chart (image) and measure the length of your feet as presecribed. Vibram sizing does not correspond to standard shoe sizes!

If you've sized in Vibrams before, note that KSOs size slightly larger than the same size in the Classic or Sprint models. So a 43 KSO will fit larger than a 43 Classic or 43 Sprint. For this reason, Vibram prescribes you size down in the KSO compared to the Classic or Sprint models. Generally, it is better to size up if you're in between sizes — you don't want your toes bending out of lack of room! Also, the KSO's closed-top design means that if you have particularly high arches or "high feet" the KSO may not fit properly and you might consider the Sprint or the Classic. Finally, some have anecdotally observed that black KSOs size smaller than other color combinations.

Read (and see!) more about the Five Fingers KSO via these reviews:

Modifications and other considerations:

Okay, I want some KSOs. How much are they? Where can I get them?

The KSO retails for around $85 and can often be purchased with free shipping from most online retailers. Find the Vibram Five Fingers KSO in stock via the Store or subscribe by email to inventory alerts.

Of course, there are other barefoot shoes worth checking out!

More Vibram Five Fingers KSO posts below —

Tags: kso

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Sandy Sommers, Russian Kettlebell Certified Instructor and owner of Charm City Kettlebells in his red Vibram Five Finger Sprints
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By pinching the fabric of the KSO Vibram Five Fingers, I can demonstrate just how thin it is.
By pinching the fabric of the KSO Vibram Five Fingers, I can demonstrate just how thin it is.
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