The more you run, the more you'll love the men's REI Co-op Swiftland long-sleeve T-shirt—it's made with microventilated SwiftTex™ fabric that's so light and cool it's like running in nothing at all.

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If you like running long trails on warm days, you'll love the men's REI Co-op Swiftland T-shirt—it's made of microventilated SwiftTex™, a fabric so airy and cool it's barely heavier than the breeze.

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Made for the modern hiker who takes a fresh, unconventional approach to life, style and the trails, the Marmot Syrocco shirt breathes easily and dries fast, so you stay cool from trailhead to brewpub.

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Whether you're exploring new trails or city streets, the men's O'Neill TRVLR Traverse shirt will keep you cool, covered and comfortable in a lightweight, sun-protective fabric that wicks moisture.

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Whether you're running a marathon or lapping the neighborhood, the men's On Tank-T running Shirt keeps you light, cool and comfortable so you can focus on your pace and not be bogged down by sweat.

Tank TopsRunning Tank Tops - DEPRECATED

With a looser fit and fabric that wicks away your hard-earned sweat, the men's Under Armour Tech 2.0 T-shirt is a go-to for high-intensity workouts and hot-weather adventures.

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Lightweight and breathable, the men's Icebreaker Tech Lite II Crewe T-shirt is a versatile top that's ready for it all. It helps regulate your temperature, wicks sweat and even stays warm when wet.

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A versatile adventure tee, the men's Icebreaker Tech Lite II Polar Paddle T-shirt lets skin breathe, provides stretchy comfort and keeps you cool when it's hot, warm when it's not.

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A versatile adventure tee, the men's Icebreaker Tech Lite II Trail Hiker T-shirt lets skin breathe, provides stretchy comfort and keeps you cool when it's hot, warm when it's not.

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Crafted from Manduka PRO tech fabric, the Manduka Tech tee performs well for any workout. Its moisture-wicking properties and breathability will keep you cool no matter the challenge.

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A moisture-wicking and UV-blocking essential, the men's Columbia Tech Trail Novelty polo shirt keeps you comfortable under the sun while hiking, golfing and bopping around town.

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Designed with quick-drying fabric and UPF 50 sun protection, the men's Columbia Tech Trail polo shirt offers optimal performance for sunny days spent on the golf course or the hiking trail.

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Want the bare minimum on the trail? The ultralight and comfortable Helly Hansen Tech Trail men's T-shirt wicks to move moisture away from your skin and the 4-way stretch offers freedom of movement.

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Stay dry and in your zone when hiking or climbing in the men's adidas Terrex Multi Half-Zip Long-Sleeve shirt. Backpack-friendly and moisture managing, it's a go-to layer under your jacket or alone.

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