This review photo shows the author testing a Under Armour UA Iso-Chill Shorebreak Long Sleeve fishing shirt on a sunny beach.

Under Armour UA Iso-Chill Shorebreak Shirts Review

- Field-tested -

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The Under Armour UA Iso-Chill Shorebreak sun-blocking fishing shirts come in two basic versions, with a hoodie and without. They’re made of polyester, but the thread and weave does more than just block the sun — UA says it sucks the heat out of your skin.

Which they very well might. Kind of. Probably a little.

To get us a closer look at the UA Iso-Chill Shorebreak shirts in person, Under Armour sent Man Makes Fire several review units to try for ourselves. After testing the UA Iso-Chill Shorebreak shirts in temperatures up to 106° Fahrenheit, this is what we learned:

UA Iso-Chill ‘Shorebreak’ Review

Under Armour claims the UA Iso-Chill Shorebreak line of shirts helps dissipate body heat and feels cool to the touch. But how?

This review photo shows the author wearing the Under Armour UA Iso-Chill Shorebreak shirt during testing.
What’s the outdoor temperature on this day? Over a 100° Fahrenheit. Turns out, wearing the UA Iso-Chill Shorebreak fishing/sun shirt feels better than going shirtless when it’s this hot out.

Many sun-blocking sun shirts, including those created for and marketed to anglers who fish in bright sun, are simply made of lightweight polyester. They’re sometimes made with nylon. Rash guards, which tend to be thicker and stretchier, will sometimes be a nylon/spandex blend.

In the case of Under Armour’s Iso-Chill fabric, the company uses a bit of science to create a special polyester fabric that feels cooler than other polyester fabrics on your skin.

According to Under Armour, the company uses flattened polyester fibers — think tiny ribbons instead of round threads — to create the weave. UA then treats the flattened fabric with titanium dioxide. That, according to UA, does a better job of pulling heat from your skin and into the fibers, which keeps you cool longer.


Staying Cool

This photo shows the author testing the UA Iso-Chill Shorebreak Long Sleeve shirt with a SUP at the beach.
The fit is slightly loose but also athletic. I’m about 6’3″ 225 lbs wearing an XL.

UA says that testing showed that athletes who wore Iso-Chill took 7-12% longer to hit their VO2 max. Why is that important? Heat causes your body to work harder to stay cool, and working hard affects your endurance, so if you stay cooler longer you’ll likely be able to exercise longer.

Under Armour talks about all this in a news release but doesn’t include links to a research study or provide any detailed evidence. So is ‘Iso-Chill’ just marketing hype?

It might be marketing hype . . . but it also seems to work.

The UA Iso-Chill Shorebreak in Action

Over the last few years, I’ve started wearing long-sleeve rash guards and lightweight sun shirts for much of the time I spend at the beach and on the river. With a good UPF 50+ sun shirt, I can avoid slathering on as much sunscreen (and I don’t need anyone to get my back).

Before I take you outside, I first tested the feeling of cool compared to other polyester shirts I have in my closet. When I touch the UA Iso-Chill Shorebreak and other shirts with my hands, I can’t feel any difference. The Iso-Chill Shorebreak shirts don’t feel any cooler.

However, when I drape the competing sun shirts over my forearm — and drape an Iso-Chill Shorebreak shirt over my other forearm at the same time — the Iso-Chill Shorebreak shirts feel a tiny bit cooler for a few seconds.

After a few seconds, I think the heat from my forearms warms the fabric and they just both feel the same.

This photo shows the author testing the UA Iso-Chill Shorebreak Long Sleeve shirt during the review process while getting ready for a whitewater rafting trip.
The wildfire smoke kept the temperatures under 100 degrees. After lots of splashing and swims to cool off, the Shorebreak dries fast.

Consequently, I think the Iso-Chill is technically working . . . but I’m not sure how noticeable it will be to real anglers who are out fishing in the sun . . . compared to other polyester fishing shirts. To test it, you’d have to find fishing shirts that are the same color, fit the same, and have the same weight of fabric. And even then, the variables of sun position, wind, and time spent outside would make it tough to come to an accurate conclusion. And who knows what happens when the ambient temperature rockets up to 106° Fahrenheit. If the Iso-Chill fibers are 106°, can they still pull heat from a 98.6° body or skin that’s at an even lower temperature than the fibers?

Need a great water-ready sun hat? Read our Shelta Hat Review!

Subtle Indicators

This produce photo shows the Under Armour UA Iso-Chill Shorebreak Long Sleeve fishing and sun shirt.
Long-sleeve version.

All that said, I can tell you two undeniable things about the Under Armour Iso-Chill Shorebreak long sleeve shirts and hoodies:

First, when it’s 106° out in the sunshine on the beach, I very much prefer wearing the Iso-Chill Shorebreak shirts over going with bare skin. It feels as if the sun’s rays warm my skin and I get hotter than when I wear the UA Iso-Chill Shorebreak. That’s not to say that I’m not warm, I’m just saying that I prefer to wear the Iso-Chill Shorebreak shirts over going shirtless when it’s super hot out. Plus, the Iso-Chill Shorebreak shirts are way better than typical cotton t-shirts. The UPF 50+ protection is also an obvious bonus.

Second, every time I’m walking out the door this summer to go do something outside, I’m grabbing an Under Armour UA Iso-Chill Shorebreak shirt to take with me. I’m not always choosing to wear the shirts every time I do something outside, but I want it handy in my pickup.

As a guy who tests a lot of different outdoor gear all the time, this is an important point because I found myself reaching for the Shorebreak shirts even when I didn’t need to have them specifically on-hand for testing and review purposes. (BTW, this is the kind of thing that helps great gear make it into our guide to the best outdoor gifts for men — and yes, the Iso-Chill Shorebreak is in there.)


Wicks & Dries Fast

Many lightweight synthetic shirts do a good job of wicking perspiration from your body. As near as I can tell, the UA Iso-Chill Shorebreak shirts still wick well despite the flattened fiber construction — which is not noticeable to the naked eye. It just looks like a high-quality weave.

This produce photo shows the Under Armour UA Iso-Chill Shorebreak Hoodie fishing and sun shirt.
Hoodie version.

To test in-the-water performance, a Man Makes Fire gear tester and I wore the UA Iso-Chill Shorebreak shirts on a whitewater rafting trip. Not only did we not get sunburned, the shirts dried quickly after going for swims and getting repeatedly splashed.

Some synthetic shirts will absorb a bit of water and stretch quite a bit when wet — the UA Iso-Chill Shorebreak shirts stretch very little, if at all, when they’re saturated. I really appreciated that the fairly loose-but-athletic cut maintained the fit even when wet.

Shop UA Iso-Chill Fishing Shirts at Under Armour and get FREE Shipping!

Competitive Alternatives & Options

Many companies are now making lightweight, long-sleeve, sun-blocking fishing shirts. If you don’t plan on hitting your VO2 max while you’re out fishing, these competitive fishing shirt alternatives might also work well for you.

Orvis PRO Sun Hoodie — The benefits of the Orvis PRO Sun Hoodie include Polygiene for odor control, integrated thumb holes, and a hidden seam pocket. The drawback is the price. The PRO Sun Hoodie costs twice as much as the UA Iso-Chill Shorebreak Hoodie.

L.L.Bean Tropicwear Knit Hoodie — If you need extra length because you’re a tall guy, the L.L.Bean Tropicwear Knit Hoodie comes in both regular and tall size options.

Simms SolarFlex Hoody — Simms offers some light camo patterns to help break up your profile while fishing, and for Simms fans, there’s no reason to stray. The thumb loops help keep your sleeve down on your forearm while casting a fly rod.

Huk ICON X Series Shirts — Compared to the lightweight fishing shirt competition, Huk makes the most color and pattern options. The biggest drawback is that most of the Huk shirts have a lot of branding in the designs, for instance, “Huk Performance Fishing” on the chest and a frequent “Huk Fishing” on the sleeves. Of course, you can also see the branding as a benefit, akin to other lifestyle performance branding that you find in other top brands — like Under Armour, for instance.

The Verdict: Just Get One

All-in-all, the Under Armour UA Iso-Chill Shorebreak long sleeve fishing shirts and hoodies are simply excellent. The fit is spot on, the cut is loose but athletic, and the price-to-value ratio is competitive. They look good and they feel good. More importantly, if you haven’t started wearing lightweight fishing shirts with a UPF 50+ rating . . . you should — and you can’t go wrong with Under Armour’s UA Iso-Chill Shorebreak shirts. Very highly recommended.

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Wicks moisture and dries quickly
UPF 50+ sun protection
Excellent lightweight fit and finish
No thumb loops
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