Friday, March 18, 2016

Tested: Fitsok Isolwool Trail Cuff socks

I'm kind of a sock junkie. I have a ridiculous number of socks for both athletic stuff and regular wear - like an entire dresser drawer overflowing with nothing but socks. Unfortunately, some of my original pairs of running socks have started to show their age (after more than 7 years - seriously, Smartwool socks used to be bombproof), and so I found myself looking for some new ones a couple of months ago.

It being winter, I wanted some that would keep me warm but would also be useful when the weather gets warmer, and to me that says wool. I also wanted some with a taller cuff, because I have a 32" inseam and most of my tights make me look like I'm waiting for the flood. I strongly believe that wearing socks that left a gap between the top of their cuff and the bottom of my wool longjohns at Oracle Trail last month was a contributing factor in the frostbite to my left big and 2nd toes, as the veins in my ankle were more exposed to cold air (despite my winter tights and gaiters overtop to seal out as much as I could), resulting in a cooling effect I've discussed before.

Being most chagrined to find that neither Smartwool nor Icebreaker was currently making socks that fit the bill - all either too short or too thin to provide real winter warmth - I decided to gamble on a 3-pack of socks I'd never heard of before: Fitsok Isolwool.

Product image from their website

What it is: Cushy crew-height socks in a 39% merino wool / 39% polypropylene / 20% nylon / 2% spandex blend.

Why you want them: Because merino wool is amazing for thermoregulation - it keeps you warm in the cold and cool in the heat - and polypropylene has excellent sweat wicking capabilities.

Duration used: About 2 months

My phone's camera dulls the VERY VIVID fluorescent green details

Inside of foot showing how nicely they hug my arch.

Price paid/purchased from: I paid $24.99 + tax for the pack of 3 pairs at the Running Room in Kitchener.

Manufacturer's description: "Reinforced Trail Cuff? Check.

The new ISW is a power-packed running sock built for the trail and beyond. Constructed with Isolwool®, the ISW utilizes merino wool and polypropylene to deliver superior moisture movement. A light cushion prevents blistering and enables prolonged performance in the harshest conditions. Wool naturally fights bacteria allowing the sock to remain clean and fresh. The ISW is designed to perform in hot or cold environments - and to excel on the trail."

Top of the sock laying flat. They are not specific to left or right foot.

Not a "seamless" toe, but I've had no issues with friction from the nicely finished seam.

What rawks: My biggest two criteria for buying socks was that they have a large wool content (eeh, we'll call 39% "large") and have a cuff that I figured would keep my ankles warm. I've also worn polypropylene liner socks for backpacking and know that they're very good at transporting moisture away from the skin, because in cold weather the biggest factor that will lead to hypothermia or frostbite is being wet. The nylon content should help with durability, as merino wool on its own can be a bit fragile, and the spandex helps them fit just right so they don't move around and cause blisters. I've seen absolutely no evidence of wear and tear on my 3 pairs yet, and they've been in regular rotation - I'd say each one has been used at least half a dozen times. I wear either a size 9 or 9.5 (sometimes 10) women's shoe - European size 41 is pretty reliable for me - and went with the size Medium in Fitsoks. With running socks, I find it's always better to have a fit that's on the snug size rather than have too much material to bunch up and raise blisters or hotspots, and in this particular case I feel I got a perfect fit. They're snug, but not too tight, and I haven't experienced any shifting when running - they even make a pair of shoes I'm a bit iffy about fit more comfortably. The cushion is of medium thickness, which is enough to fill a bit of space if your shoes are a tad too large but not enough to require that you go up a half size, and runs throughout the whole foot of the sock save for the top of the arch. The sole seems to have some extra stretchiness to it in the form of some white stripes that really hug my foot nicely. I am most impressed, though, by the cuffs - they're a double layer of material that not only bridges the gap to the bottom of my shortest set of tights (with at least 3/4" of overlap), but feels very warm and even protects my skin from my occasional tendency to catch the sole of my shoe on the inside of my ankle during my stride. Yeah, I'm clumsy.

Very snug, stretchy sole.

Good cuff height for those who find their tights a bit on the short side.

Double layer of material shown by turning the sock partially inside-out.

What sucks: I really would prefer that these socks have a higher wool content (>50%), as I find it better for keeping me warm and I already have plenty of thinner merino wool socks for summer running. That said, I have run in these down to -13c/9f and my feet stayed warm. I haven't had much opportunity to test them in slushy conditions, which is where I've found that my old Smartwool socks really save my bacon (or rather, my toes), but what I've seen so far makes me reluctant to rely on them as much as I do my older, higher-wool-content pairs. It would be a little more fun if the 3-pack were different colours (which don't seem to exist in this model - if you don't like charcoal grey and eye-searing green, you're SOL), but I will admit it sure makes mating them up after doing laundry very easy. If you're in the middle or at the lower end of the range for a particular size, you may experience some bunching - I essentially went a half-size down to achieve what I consider a perfect fit.

A nice, snug fit even if your feet are a bit mis-shapen

What I'd like to see: Higher wool content and different colours.

What I'm saying: While they're not perfect, at $25 for 3 pairs these socks are a steal compared with other brands for which I've paid $20 for a single pair. If you're in need of some ankle protection, they're well worth the gamble for the price, even if you may want to stick with something with a higher wool content for long runs in cold or wet conditions.

For further edification: These were reviewed by Run Oregon and on, or you can check out Amazon reviews.


  1. I love Fitsok. They were in the swag bag at a race I did a few years ago, and it may or may not have been a contributing factor for why I signed up for the same race a year later.

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