Updates to Vibram FiveFingers Trek Ascent Insulated

  • One of the biggest differences in the FiveFingers Trek Ascent Insulated over its standard model is the use of the Ice Trek rubber compound, which is tailor-made for running in wet, icy conditions.
  • Because the insulated model is built for the cold months, the shoe is also lined with wool in the collar, the interior, and the sockliner. The wool works as intended as it keeps the foot warm as long as the foot does not get wet in the first place.
  • To prevent the foot from getting wet, Vibram added a water-repellent upper. Although this is far from being fully waterproof, the water-resistant properties should be able to make runs very comfortable during wintry conditions.
  • The slight padding in the collar and the tongue makes the shoe more comfortable than the regular model. Plus, it also adds to the warmth in winter.

Size and fit

Vibram confirms that the Insulated version of the Trek Ascent runs at least a size smaller than the usual fit in most Vibram shoes. Still, it would be a very good idea if runners can try on the shoe as it would significantly help in getting a more comfortable run. The fit is snug in a good way with plenty of toe box room. As always, the toe slots accommodate all five toes for a natural splay.


One of Vibram’s premium outsole technology, the Ice Trek, is used in the underfoot of the Trek Ascent Insulated. The rubber compound is a beast in wintry conditions, particularly on the trails. It has a very aggressive lug design that will raise the confidence of users while running, walking, or hiking. There are also “flex grooves” between the lugs that add flexibility to the shoe. The 4mm outsole provides decent protection and ground feedback at the same time.


Handling “midsole” duties is the 4mm PU and wool sockliner. It gives added protection and a little cushioning in the Vibram Trek Ascent Insulated.


The upper of the Trek Ascent Insulated is one of the most innovative in Vibram’s line. It features a high-tenacity nylon and polyester for a durable, water-resistant, and glove-like fit. As the collar and the interior have wool, the shoe keeps the foot deliciously warm during winter. The fit is snug and really feels like a second skin. A traditional lace-up closure keeps the fit tight and secured throughout the run.


The current trend of Vibram FiveFingers Trek Ascent Insulated.
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Jens Jakob Andersen
Jens Jakob Andersen

Jens Jakob is a fan of short distances with a 5K PR at 15:58 minutes. Based on 35 million race results, he's among the fastest 0.2% runners. Jens Jakob previously owned a running store, when he was also a competitive runner. His work is regularly featured in The New York Times, Washington Post, BBC and the likes as well as peer-reviewed journals. Finally, he has been a guest on +30 podcasts on running.