REI Co-op  Flash Shorts - Men's

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.

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.

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!

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.

I’ve been using the REI Co-op Flash Shorts for workouts, hikes, and general outdoor adventures, and they definitely punch above their weight for the price. Pros Lightweight & comfortable. These shorts feel feather-light when you’re on the move, so you barely notice them even on long hikes or runs. The fabric has plenty of stretch and breathability, making it comfortable for rapid movement and heat management. Quick-drying performance. Built with a fast-drying nylon/spandex blend, they handle sweat and unexpected wet conditions very well. They dry quickly after rain or river crossings. Great for active use. These are especially well-suited for running, trail hiking, or any activity where low weight and quick drying are priorities. The UPF protection is an added bonus on sunny days. Cons Lack of practical pockets. While there is a zippered pocket and standard hand pockets, you quickly notice what’s missing. The front pockets are quite deep — so deep that smaller items like keys or cards feel like they’re disappearing down a rabbit hole. They’re not great at securing things without a lot of movement or digging around. No back pocket. These don’t include a traditional back pocket, which limits how much you can comfortably carry. If you need to pack multiple items (phone, wallet, snacks) without a pack, these shorts feel lacking. Not ideal for storage-heavy use. They’re awesome when you want to go light, but if your adventure means carrying more gear in your pockets, these might feel frustratingly limited. Verdict The REI Co-op Flash Shorts are a solid pick if lightweight comfort and quick dry performance are your top priorities especially for exercise, running, or minimalist adventures. Just be aware that the pocket situation isn’t ideal for carrying multiple items without a bag or pack.

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.

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.

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

I am an REI member and they always offer up good sales in the spring. We went to the local store and I really didn't need anything, but I stumbled on a rack of these flash shorts. Very lightweight and comfortable; just perfect for the summer heat down here in the southeast. I've owned them for 5 weeks and I tend to wear them around the house daily. They launder in cold water very well. I've worked out a few times in them on the rower, but mostly they are just for being comfortable. Apparently these are designed for hiking, but I haven't really tried them out in that fashion but since they are so lightweight I suspect they would be perfect. There are two side pockets and one zippered that is good for keeping a money clip and ID. The size pocket holds me mobile phone with a case and it doesn't overload the shorts like others do. The waist band stays right in place. If I took the case off, it would be even better. The draw string adjusts well in case your weight goes up or down a few pounds. The pairs I bought are in the blue/gray category. They also have black, but that doesn't appeal to me. I loved them so much that today I decided to buy a 2nd pair and was able to get them for the same price as May. Picked them up in the store an hour ago. I am a 32 inch waist and these fit great in a medium. Some say they run large, but to me they run true. At the lower price, these are an easy purchase. I suspect they will last a long time if maintained properly.

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.