Sure, the weather looks nice for now, but what if it turns on you quickly?  Bring the Pearl Izumi Infinity Jacket along, and you’ll be ready for your long trail run regardless of what springtime conditions you encounter.

Pearl Izumi Infinity Jacket Features:

  • Main panel material 100% polyester 90g/m2
  • Mesh panels 92% polyester, 8% elastene
  • Weight 70z (200g)
  • ELITE barrier fabric
  • 2.5” mock neck with soft wicking liner
  • Direct-Vent back and underarm panels
  • Full length internal draft flap with zipper garage
  • One zippered arm pocket with media cord hole
  • Internal sleeve mitt
  • Semi-form fit
  • MSRP $80

Pearl Izumi Infinity Jacket Review

From a trail runner’s standpoint, spring is the “just in case” season: if you’re heading out for a long run, it’s always a good idea to have a weather-resistant layer on hand in case the temperature drops quickly, or in case a quick shower blows through.  However, you don’t want anything too heavy or bulky, or you might end up just wearing it around your waist all day.

Pearl Izumi’s entry in the lightweight shell category is the Infinity jacket, featuring a barrier fabric called ELITE that is windproof and water-resistant, even in relatively harsh conditions.  I’ve been caught in a handful of cloudbursts with this jacket, and was pleased with how it performed: there’s enough protection to help you ride out temporarily foul weather, but it’s thin and breathable enough to stay comfortable before and after the storm passes.

Water beading off ELITE barrier fabric

Additional protection from the elements is provided above the neckline with a collar that sits comfortably below the chin in the stand-up position, and below the sleeves with internal hand mitts.  The latter is a pretty cool innovation that lets you warm your fingers up without having to stow a pair of gloves with you.  When the mitt isn’t used, the cuff of the sleeve is asymmetrical, longer on the upper arm and shorter on the palm side, and doesn’t feel remarkably different than a standard cuff.  I’d like for the mitts to be a bit longer, as they stretch the sleeves pretty tightly when I use them.

Mitt cuff for finger insulation; mesh underarm surface

Ventilation for the Infinity is managed by a perforated mesh material that starts in the armpit area and runs down the length of the arm on the undersurface.  The mesh also contains elastene to allow mild stretchiness and improved range of motion.  There’s a thin strip of mesh fabric running diagonally down the shoulder blades that is covered by a flap of the ELITE fabric.   The total surface area of mesh is smaller than similar jackets in this category, so the Infinity tends to run on the warm side; the most comfortable temperature ranges from my testing were high 40s to mid 30s with a short-sleeve base layer underneath.  If the mesh portions were extended down the sides of the trunk or across a wider portion of the  back, that would be ideal.

Good Infinity Jacket

  • Great weather resistance for such a lightweight garment
  • Very comfortable fit, material, and flexibility for multi-hour use
  • Sleeve mitts are a great innovation for cold fingers

Bad Infinity Jacket

  • Increased surface area of mesh would improve ventilation
  • Finger mitts need to be a little bit longer

Bottom Line: Pearl Izumi Infinity Jacket

If you’re unsure of the conditions, there’s not much downside to wearing the Infinity jacket; it has a great protection to weight ratio, and stays comfortable for as long as you decide to stay out there.

Buy Now: Find Pearl Izumi Jackets at

About Author

Donald is a physical therapist, ultrarunner, barefoot aficionado, and father of three with more than 20 years of experience in endurance sports. When he's not training for ultramarathons, he enjoys hiking or slacklining with his family in Monterey County, CA.

1 Comment

  1. I just got this jacket and love it. For temps below 30 degrees I pair it with an Arcteryx fleece and works great. Pearl Izumi has one of if not the best running gear and is far superior to Nike when it comes to technology. Great gear!

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