Meet Gym Girl: A Workout-First Wardrobe With Retro-Sport Energy

September has its own fresh-start energy. If you’re ready to return to a routine—or try a new one—you don’t have to wait until January.

Meet Gym Girl, Curtsy’s edit of secondhand activewear and sporty layers. The formula is simple: start with pieces that make sense for your routine, then add the retro details that make the outfit feel like you. (curtsyapp.com)

Below, we’ll help you build that formula for lifting, Pilates, running, HYROX, or court time. You’ll also find practical secondhand search terms, outfit ideas, and tips for checking activewear listings before you buy.

The Gym Girl Formula

The collection starts with what your workout asks of you. The styling comes next.

Begin with a functional foundation: dark leggings or shorts, a tank or bra with your preferred level of support, and shoes designed for the activity. Add a layer you can wear from the workout to the rest of your day. An oversized tee, track jacket, zip-up, or pair of swishy warm-up pants can all work.

Then bring in some personality. The current version feels more mixed than matched. Black, navy, espresso, and heather gray sit next to primary-red accents, contrast piping, striped socks, and vintage athletic graphics. Instead of looking like one set purchased at once, the outfit can feel collected over time.

That mixed approach is especially easy to build secondhand. A vintage track jacket can sit next to the leggings already in your rotation. An old ringer tee can give simple bike shorts a more personal finish.

Capri leggings and foldover flares fit the retro-sport mood, but they’re options, not requirements. If they aren’t your thing, skip them. A reliable pair of 7/8-length leggings is still an easy foundation.

This year’s “lock-in” conversation is also bigger than one workout. TikTok’s 2026 trend report connects the mindset to goals ranging from studying to fitness, with community encouragement and accountability as part of the appeal. (ads.tiktok.com) Maybe your reset is public. Maybe it’s simply a promise to yourself.

There is no single Gym Girl workout—and there shouldn’t be a single Gym Girl outfit.

Start With How You Move

For strength training, look for a waistband that stays secure and a cut that gives you comfortable range of motion. Your preferred coverage and support will depend on the workout, so adjustable straps or a longline silhouette can be useful options. For many lifting sessions, a stable cross-trainer may feel steadier than a very soft, highly cushioned running shoe.

For Pilates, try 7/8 leggings, capris, or foldover flares with a fitted tank. A close-to-body fit keeps extra fabric out of the way and can make alignment easier to check. Add grip socks if your class or studio requires them, then throw on an oversized zip-up or track jacket for an easy extra layer.

For run club, start with storage. Pocket shorts or leggings can keep a key or phone secure, while a small zip pocket can handle the true essentials. Choose the bra support that feels comfortable at speed. If your club runs on pavement, look for a shoe designed for road mileage rather than assuming your lifting shoe will work the same way.

For HYROX or functional training, choose pieces that can stay secure, manage sweat, and move between running and strength stations. The official HYROX format alternates eight one-kilometer runs with eight functional workout stations, so versatility matters. (hyrox.com) A training shoe with dependable traction and enough comfort for the running portions may be a good starting point.

For a rec league or court time, this is your chance to bring in the playful pieces. Try contrast-trim shorts, a vintage athletic tee, swishy warm-up pants, or a striped jacket. Shoes should still suit the sport and surface, but the layers around them can carry more of the retro idea.

You don’t need separate wardrobes for every activity. Start with the movement you do most, then add pieces that expand your options.

Add the Retro Details

Retro-sport details can give a practical outfit more personality without changing its function.

For a subtler version, choose one or two details and let simple workout staples ground them. Pair black 7/8 leggings with a red-and-white ringer tank. Wear navy pocket shorts with a heather-gray tee and primary-red crew socks. Add a color-blocked track jacket to an espresso-and-cream base.

Contrast piping is another easy update. It adds definition to a tank, bra, or pair of leggings without requiring a bright head-to-toe look. Vintage athletic graphics can create the same effect—even if the team is simply you versus Tuesday’s workout.

Prefer more color? Take the idea further. Try striped socks with a bright track jacket, or pair swishy pants with a fitted contrast-trim tank. A foldover flare can work with a cropped zip-up for a full throwback silhouette. You can also mix several primary colors if that feels more like you.

The point isn’t to follow one styling formula perfectly. It’s to find the level of retro energy that makes your workout staples feel personal.

Shop Your Closet First

Before you buy anything, check what you already have. Dark leggings, a fitted tank, an old team tee, a zip-up, or a track jacket may be enough to start the formula. Even one pair of striped socks can shift the mood.

When shopping secondhand, get specific. Try searches such as 7/8 pocket leggings, 5-inch bike shorts with pockets, adjustable high-impact sports bra, vintage track jacket, contrast-trim running shorts, or foldover yoga pants. If you already know a model that works for you, searching its exact brand and style name can narrow the results faster.

Read each listing closely. Check photos and descriptions for waistband condition, pilling, thinning fabric, stretched straps, working zippers, and shoe tread. Look for confirmed product details such as pockets, inseam, adjustable straps, or the type of activity a shoe was designed for. If something isn’t clear, ask the seller for a close-up or measurement.

Listing activewear from your own closet? Include the exact style name when you know it, along with the size, inseam, pocket placement, strap details, and any visible wear. Clear information helps the next person decide whether the piece fits her routine—and gives it a better chance of getting back into rotation.

Ready to find your formula? Explore the Gym Girl collection on Curtsy and choose the pieces that make showing up feel a little easier.