The Stio Trax Power Grid Half Zip Hoodie is the perfect base layer for women who are after a lightweight, highly breathable, and feature-rich synthetic design to wear year-round. Although not our favorite for stand-alone warmth, it is perfect for women on the go, effectively trapping body heat and shedding sweat during high-output adventures.
While the Trax Power Grid has the look of a midweight base layer, it's important to clarify that this layer performs best when you are actively moving and is not our first choice for sedentary warmth during the coldest months of the year. That said, the raised Polartec Power Grid fleece, along with a large hood, high neckline, longer torso, and sleeves complete with thumb loops, effectively traps body heat while releasing sweat through the lighter portions of the fabric.
The Trax Power Grid is constructed from 91% Polyester and 9% Spandex, with a relatively lightweight fabric measuring only 119 g/m2. The magic of this layer is its ability to shed moisture and trap body heat within the raised Polartec fabric, while maintaining a lightweight, comfortable design that's perfect whether you're on the skin track, out for a skate ski, running, or climbing your favorite route. The versatile warmth makes this layer your new go-to for all times of year.
If ever there was a layer designed to provide maximum thermoregulation along with fast moisture wicking capabilities, it's the Trax Power Grid. It quickly became our favorite layer for activities where we knew we would quickly work up a sweat. The raised Polartec Power Grid fleece fabric, along with a slightly loose/regular fit, leaves room for air to circulate and wick away moisture, keeping you warm, dry, and comfortable.
Whether we were pushing the pace on the skin track, shoveling the driveway after an infamous Sierra Atmospheric river, or working on our winter climbing project, the moisture control allowed us to maintain body heat without building up a ton of sweat in the fabric. The downside of this excellent thermoregulation and moisture control is that the layer doesn't provide a ton of standalone warmth. If you try to wear it on a slower-paced hike, or when riding up the chairlift at the resort, you might feel the breeze more than you'd like.
It's obvious that Stio put a ton of thought into the overall comfort and fit of the Trax Power Grid, it has a goldilocks fit that doesn't feel too restrictive or too baggy. Action gussets and spandex allow for a full range of motion, along with heat-transfer labels so you don't have to deal with a big, itchy tag on the back of your neck. Flatlock seams are great for both durability and next-to-skin comfort, while the elastic-lined hood traps even more body heat by fitting close to the head.
Although the raised Polartec fabric feels pretty good on the skin, it could be a little softer and stretchier. We noticed this especially when we wore the Trax hoodie back to back with some of the finer woven merino options. That said, the structure of the design helps maintain its shape and durability. If this becomes a go-to layer for you (like it did for us), it will likely see a ton of use, and the added durability will be an easy trade. There is a zipper at the lower hemline that allows you to store a car key, credit card, or energy gel, but the climbers in our testing crew noted it interfered with their harness.
Despite the raised grid pattern and see-through fabric sections on the Trax Power Grid, it's easy for our testers to stand behind the durable construction thanks to a sturdy synthetic blend built to last. Flatlock seams and a YKK zipper up the quality of this design, while the synthetic fabric withstood some pretty aggressive field testing.
In addition to a durable construction, we really appreciated the anti-odor finish that prevented the Trax from collecting sweat from all of our adventures. This synthetic-blended design remained odor-free after multiple days of wear, a performance feature typically only found in merino wool. While we didn't notice any snags or tears during our testing period, we can imagine the more delicate see-through sections of the design are prone to failure due to their ultralight, thin design.
The synthetic, raised-fleece fabric of the Trax Power Grid, along with its see-through grid pattern, allows this layer to dry extremely quickly in the sun. It was rare for the layer to absorb sweat when worn on its own, so you probably won't have a problem with dry time anyway. But if, for some reason, it gets super sweaty (like when layered under a heavy jacket), it only takes about 10 minutes to dry once exposed to fresh air.
Even though this is a midweight layer, it still boasts a faster drying speed than even some of the lightest-weight layers in our lineup. In our controlled drying tests in 30°F at 7,000 feet in Crowley Lake, California, the layer only needed 40 minutes to fully dry in the sun. While it may not be the warmest layer that we tested, it is most certainly the most breathable and offers a competitive drying speed.
Our testers found the raised fleece fabric of the Trax Power Grid hoody was rather easy to layer under and over, but it plays best with other synthetics. Anything wool or fleecy would often be harder to layer, as the Polartec fleece panels grab the textured fabric, causing uncomfortable bunching. It layered nicely under our ski bibs and climbing harness; we just didn't load the pocket at the hemline while climbing, as it interfered with our harness. Likewise, it could interfere with the hip straps of a backpack if you choose to take this on an overnighter.
We love that you can tuck the thumb loops away when you're not using them for additional warmth, sun protection, or to keep the sleeves in place while you throw another layer over top.
If you're an active female seeking a stylish, highly breathable, and comfortable base layer that will trap your body heat while also shedding sweat, the Stio Trax Power Grid Half Zip Hoodie is worthy of your investment. Although a little more expensive than your average base layer crew, this feature-rich design includes a high neckline, center zipper for trapping or offloading body heat, a large hood, discreet thumb loops, and a stash pocket that combine to create the perfect layer for women on the go.
If you prefer a synthetic base layer that better optimizes stand-alone warmth, one of our favorites is the Arc'teryx Rho Hoody. We've tested many versions of the Rho over the years and love the high-quality construction, along with the hood, balaclava neck line, and longer torso that better trap body heat when it counts. If you're on a budget, we love the REI Co-op Midweight Base Layer Crew thanks to its comfortable, stretchy fabric that feels great next to your skin.
| Awards |  Best Breathability for Fast Paced Movers |
|---|---|
| Price | $129 List Check Evo (on sale!) |
Overall Score  |
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| Star Rating | |
| Bottom Line | This lightweight hoody is a perfect base layer designed for year-round use, thanks to warm Polartec fabric with grid-patterned breathability that thrives during active cold weather pursuits |
| Pros | Highly breathable, great four season layer, durable material, fast drying speed, solid wicking performance, excellent performance fit, discreet and comfortable thumb loops |
| Cons | Not best for sedentary warmth, fabric interface could be softer, spendy, difficult to layer with wool |
| Rating Categories | Stio Trax Power Grid... |
| Warmth (25%) | |
| Breathability (20%) | |
| Comfort and Fit (20%) | |
| Durability (15%) | |
| Drying Speed (10%) | |
| Layering Ability (10%) | |
| Specifications | Stio Trax Power Grid... |
| Fabric Weight Class | Lightweight |
| Material | Polartec® Power Grid™ Fleece, 91% Polyester, 9% Spandex, 119 g/m2, Wicking and Anti-Odor Finish |
| Fit | True to size |
| Odor Control Fabric | Wicking and Anti-Odor Finish |
| Avaliable Cuts | Crew, Hoody |
| Torso Length | Medium |
| Thumb Loops | Yes |
| UPF Sun Protection | None listed |
| Flat-lock Seams | Yes |
| Measured Weight (Size Small) | 7 oz |
