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Run light—run right.

The Smartwool PhD Run Ultra Light Micro Sock is a super-lightweight, micro sock that features a blend of moisture-wicking nylon, non-itchy merino wool for comfort and odor prevention, and elastane for just enough stretch to keep your feet moving free on the road or trail.

  • Merino wool/nylon/elastane blend
  • Ultralight

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Here's what others have to say...


True to fit even after multiple washes

  • Fit:True to size
  • Height: 5'11"
    Weight: 190 lbs
    Size Purchased: Large

These pad run socks are incredible! I have multiple pair and use them for all my outings. The large fits my wide 9. They are true to fit even after multiple runs and washes.


Great Socks!!!

  • Familiarity:I've put it through the wringer
  • Fit:True to size

These are by far the best socks that I have ever owned. They are incredibly comfortable and durable. After wearing them all day they are virtually odor free.


Good socks but pills easily

  • Familiarity:I've used it several times
  • Fit:True to size
  • Height: 5'8"
    Weight: 170 lbs
    Size Purchased: Large

I have used this sock for about one month and around twice per week. They are so far durable but the bottom pills a lot. It doesn't seem to be worn out soon but my other smartwool socks don't pill so mush. I think it is maybe due to the ratio of nylon to wool. My personal conclusion is more wool means less pills.


Sock that keep going

  • Familiarity:I've put it through the wringer
  • Fit:True to size
  • Height: 6'0"
    Weight: 210 lbs
    Size Purchased: L smell even after multiple times wearing them. Durable and versatile even on short hikes. Second pair purchase. Large fits a 10 foot. Very limited show if any around shoe line.

Men's PhD Run Socks

Professional Ultra Runner & Fan Field Tester Timothy Olsen shares how the PhD Run socks help him go far, and feel good.



  • Familiarity:I've used it several times
  • Fit:True to size

great sock, i'm an 8.5/9 usually and the M was just a bit too small