REI Co-op Flash Shorts - Men's
Fast-and-light adventures? Move freely in these stretchy REI Co-op hiking shorts with a 7 in. inseam. The quick-dry fabric has a durable water repellent and provides UPF 50+ sun protection.




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- Flash hiking shorts perfectly balance weight, durability and function
- Lightweight, 4-way stretch nylon/spandex fabric breathes well and dries quickly
- Durable water repellent (DWR) made without PFAS helps moisture bead up on the surface
- UPF 50+ sun protection
- Roomy hand pockets
- Right hand pocket has an internal stow pocket for a card or key, holding contents closer to your body for less bounce
- Secure, zippered thigh pocket allows you to easily access contents even while wearing a pack with a hipbelt
- Low-profile, pull-on waistband sits comfortably under a pack hipbelt and has an internal drawcord for adjustability
- Waistband uses our breathable, quick-drying and moisture-wicking Swiftland Grid material
- Crotch gusset panel also uses Swiftland Grid material for great venting and moisture management
- Standard rise
- 7 in. inseam reduces weight and takes up less space in your pack on thru-hikes
- Machine wash cold; do not bleach; tumble dry low
- Contains materials that meet the bluesign® criteria
- REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
Imported.
View the REI Co-op Flash Product LineView all REI Co-op Men's Hiking Shorts| Best Use | Hiking |
|---|---|
| Fabric | 87% nylon/13% spandex (bluesign approved) |
| Inner Liner | No |
| Sun-Protective Fabric | Yes |
| UPF Rating | 50+ |
| Quick Drying | Yes |
| Number of Pockets | 4 |
| Inseam (in.) | 7 inches |
| Gender | Men's |
| Weight | 5.6 ounces |
| Sustainability | Contains materials that meet the bluesign® criteria From a Climate Label Certified brand |
Fits slightly large based on reviews
| XS | S | M | L | XL | XXL | XXXL | 24 IN Waist | 26 IN Waist | 28 IN Waist | 30 IN Waist | 31 IN Waist | 32 IN Waist | 33 IN Waist | 34 IN Waist | 35 IN Waist | 36 IN Waist | 38 IN Waist | 40 IN Waist | 42 IN Waist | 44 IN Waist | 46 IN Waist | 48 IN Waist | 50 IN Waist | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chest | 35 | 36 - 38 | 39 - 41 | 42 - 45 | 46 - 49 | 50 - 53 | 54 - 57 | |||||||||||||||||
| Sleeve Length | 32 | 32.5 | 33 | 33.5 | 34 | 34.75 | 35.5 | |||||||||||||||||
| Waist | 27.5 | 28 - 30 | 32 - 34 | 36 - 38 | 40 - 42 | 44 - 46 | 48 - 50 | 24 | 26 | 28 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 38 | 40 | 42 | 44 | 46 | 48 | 50 |
| Hip | 33.5 | 34.5 - 36.5 | 37.5 - 39.5 | 41 - 43 | 44 - 46.5 | 47.5 - 50.5 | 51.5 - 54.5 | 32 | 33.5 | 34.5 | 36.5 | 37 | 37.5 | 38.5 | 39.5 | 40.25 | 41 | 43 | 44 | 46.5 | 47.5 | 50.5 | 52.5 | 54.5 |
| Inseam | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 |
Sizing Notes
Measurements are stated in inches unless otherwise indicated. Size chart values represent body measurements, not garment measurements.
SHORT: Some pants are available in short sizes, which generally means an inseam that is 2.5 inches shorter than regular sizes.
TALL: Some pants, shirts, jackets and parkas are available in tall sizes, which generally means an inseam that is 3 inches longer and a rise that is 1 inch longer, a shirt or jacket body that is 2 inches longer, a parka body that is 2.5 inches longer and sleeves that are 2.5 inches longer than regular sizes.
Capri or cropped pants have an intentionally shorter inseam—reference the technical specs instead of this chart.
Inseam is measured to the floor.
Better gear is built together
From feedback to field testing, all of our gear is dialed-in by REI Co-op members. Their adventures informed every stitch and detail—making for better, longer-lasting gear.


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Customer Images
Solid all-around active shorts
I've tested these on multiple trail runs and gym sessions. The fit works well for my frame (6'4", 31" waist, 36" inseam) in a Medium. The drawstring keeps them secure without slipping during activity. The 7" inseam is a good length for active use. The nylon/spandex material is stretchy and quick-drying. Ventilation panels are located on the back just below the waistline and along the inseam, which helps manage moisture during high-output activities. The pocket setup is pretty nice, both main pockets are very large but hold items well. The main right pocket includes a smaller inner pocket for keys or small items. There's no keyring attachment, but the zippered pocket handles secure storage. The pockets sit on the front/outside of the thighs, which helps prevent items from bouncing during running. The Odyssey color is gray with a subtle blue tint. No chafing issues on longer runs, and the waistband stays comfortable throughout my workouts.
Ultra Light Shorts
These shorts impress me with their extreme lightness. I do not have a scale for weighing light items but they feel undetectable. The material offers enough elasticity to allow freedom of movement. But, it also offers enough strength to not feel fragile. We currently have winter weather here so Icannot try them outside for walking or hiking. However, they feel very comfortable indoors and I believe they will function well in the heat. They do not have a liner and I would not be comfortable wearing them without a brief. But that will be a personal decision.
Exactly what you want in this type of shorts
These shorts are great overall. So far, I have worn them for light yoga and a short hike. The material is surprisingly stretchy and breathable, leading to a comfortable fit. The breathability is enhanced by a mesh lining in just the right spot (i.e., along the upper back). I also love the pockets, as shorts like these too often go without them. They easily fit my iPhone 16 Pro with room to spare. The zipper option is also great for a set of keys. I am also a fan of the inseam length, as it rests just at my knee. Highly recommend!
Lightweight and super comfortable
From the first time I put these shorts on, they felt like they were my favorite shorts. They're made from a nylon and spandex blend, thus are breathable and lightweight with that stretchy-ness that spandex provides. There is a zipper pocket on the right pantleg that is perfect for keys, but because of how lightweight the material is, a phone might be uncomfortable to have since it'll bounce around with its heavier weight. The pictures show the mesh lining in the back of the shorts, and the drawstring in the front. I like how the drawstring is inside the short, so they wont hang outside the shorts. Because they are active shorts, they don't have a front zipper, which doesn't bother me but is something to be aware of.
Great all-around shorts
These are great, lightweight shorts that you can use for a whole bunch of different activities. They have a nice amount of stretch in them, and the zipper pocket on the side is useful for securing things like a key. I really appreciate the above-the-knee length. It makes it easy to move in without being too short. The waistband is very comfortable and doesn't pinch at all. As the weather gets warmer I will be reaching for these for a lot of the outdoor activities that I do.
No Flash, No Problem
These 4-way stretch hiking shorts are certainly comfortable. The pocket configuration is well done and practical. They’re lightweight, but not so much so that I’d worry about doing some heavy lifting in them. The Swiftland Grid material is excellent and will be wonderful in warm summer weather. These run large for “XL”. Including a photo showing comps with other XL’s in my rotation. These are the largest of the bunch. Note: the REI sizing chart does reflect a more relaxed fit.
Amazing shorts
These shorts are amazing! They are very comfortable and despite this being a size up from what I usually wear (I’m usually an XL in shorts) the drawstring works very well in tightening up the shorts. Based on the material alone these could definitely double as swimming trunks or if I am fording a deep stream on trail. I mostly use these around the house however but will be testing them more outside when the weather breaks
Runs Large
I received these products for free from the REI Trailblazers sampling program in exchange for my honest review. These shorts are a nylon (87%) and spandex (13%) blend. I like nylon hiking products, and these are very comfortable on the skin. Like the two ample pockets. Not sure about the front zippered pocket. The shorts appear to run large; I am a 36 inch waist and normally wear large, but these large shorts are too big on me. I think these are good shorts but recommend trying them on before purchase to get the best fit.
Comfy but not baggy shorts
I used these shorts at home and on hikes in the Anza Borrego desert. They are board-shorts long, with slightly stretchy, super soft, quick-drying fabric. I found the fit to be "classic", which is to say loose enough to be easy to be move in but not so loose as to be baggy like many swim trunks are. These have a smooth drape when on you. They are terrific!




