Pearl Izumi Infinity In-R-Cool SS Shirt


Manufacturer Description

The men’s Infinity In-R-Cool Short Sleeve features our innovative In-R-Cool fabric
technology that cools the body while you exercise. This is the ultimate lightweight hot weather running top.


  • Semi-Form Fit
  • ELITE Transfer fabric with In-R-Cool technology provides optimal skin cooling and moisture management when you perspire
  • Direct-Vent panels provide superior ventilation
  • Screen-print design on the back
  • Reflective elements for low-light visibility
  • Body Fabric – 100% polyester/ UPF 50+ with Ice-fil, 100 g/m2
  • Mesh Fabric – 92% polyester 8% elastane/ UPF 50+, 185 g/m2
  • Available in 5 colors
  • Measured size medium
    • Weight – 124 g (4.4 oz)
    • Pit to Pit – 52 cm (20.5 in)
    • Center back – 68.6 cm (27 in)
  • Retail – $45

YMMV Review

I was looking for a lightweight summer running top. I decided to try one of Pearl Izumi’s Infinity In-R-Cool SS Shirts. Part of the Infinity Collection, Pearl Izumi’s performance collection, it is a mix of technical elements and performance.

Design ★★★★☆

When you pick up the Pearl Izumi Infinity In-R-Cool SS Shirt the first thing you notice is how light the fabric s. The shirt is made out of 2 fabrics. The main fabric is a polyester fabric with In-R-Cool technology built in. In-R-Cool fabric reflects UV light like white fabrics no matter the color. This allows you to wear colored shirts with the same performance of a white shirt. The Ice-fil technology is a sweat-activated cooling technology which reacts with perspiration to cool the body surface temperature by 5%. The second fabric is a mesh fabric over the shoulder blades, under the arms, and down the sides. This fabric is a polyester and Elastane mix for more stretch and breathability. The fabrics combine to create a lightweight and breathable shirt that is made for hot weather running. All the seams are flat locked to reduce chafing. In the upper back Pearl Izumi has added some screen printed graphics for style as well as adding a bit of structural support to the upper back. There are 3 reflective logos on the shirt for night visibility, on the chest, back, and left sleeve.

2 Fabrics Used

Fit ★★★½☆

It is hard to rate how a shirt fits, especially if it is not a tight fitting one. The Pearl Izumi Infinity In-R-Cool SS Shirt fit me as expected but did not wow me. The medium is what I normally wear and did in this as well. It is supposed to be semi-form fit meaning it will fit close but not tight. That is a pretty good explanation of the fit. There is a little room around the whole shirt but no excess material. It sits slightly lower around the neck than some other running shirt I own. On one sunny run I got a little sunburned in those areas that have been covered by my other shirts. The seams are well placed, I did not have any issues with chafing on longer runs. It feels so light and soft you will not even know you have it on.

Back View

Performance ★★★★☆

The shirt has been great for running in the summer. It is so light you do not feel it but it blocks the UV rays and aids in moisture transport well. When wet it dries really quickly. As most polyester shirts will, it does smell after using it. The shirt has the In-R-Cool technology built in which I am not sure I can tell it is working or not. The shirt feels cool but I am not sure this is from the lightness of the shirt or the In-R-Cool fabric. Might be from both but it is difficult to truly test these properties of the shirt. The reflective elements are a nice touch, they are small but they do flash when hit with light. I have not had any issues with the durability of this shirt and will check back if I do.

The Fit on Me

Overall ★★★★☆

The Pearl Izumi Infinity In-R-Cool SS Shirt is a good option for hot summertime running. It is lightweight and soft to the skin while having many performance characteristics. The fabrics have UPF 50+ for blocking UV rays and the mix of fabrics move moisture well. The fit is to be as expected, similar to other Pearl Izumi garments. There are no pockets on this shirt but all the other performance features are. At $45 it is a bit more expensive than other more basic running shirts out there but I think if you try it you will be able to tell the difference. It also comes in a singlet, sleeveless, and long sleeve version. As always, Your Mileage May Vary.


  • UPF 50+
  • Lightweight
  • Flat lock seams


  • Sat slightly lower on neck


About the Author

I am an avid runner, cyclist, swimmer, hiker, climber, skier and many other activities that would make this list too long. I started Your Mileage May Vary Reviews in Early 2011 to combine two of my passions: sports and gear.

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