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Due to their flattening silhouettes and practical design for movement, workout one pieces and bodysuits are no stranger to activities like Pilates and dance.
When I noticed Bandit, a running brand from Brooklyn, New York, was offering running one pieces in their latest collection, though, I was initially skeptical. Could a onesie be comfortable or practical for intense cardio, given my short torso and need for chest support?
To determine the best one pieces for working out versus just doing errands, I tested onesies from various brands, evaluating their comfort, support, and functionality across different activities. Here’s what I found…
Why Workout Onesies Are Everywhere Right Now
There’s a reason this trend is taking off:
-No outfit planning! One piece and you’re done.
-No adjusting mid-workout so nothing riding up or shifting.
-Streamlined fit: fewer seams = less chafing.
-Flattering by design with built-in shaping and support.
It’s the easiest way to look put-together at the gym with minimal effort (which, honestly, is half the battle).
What to Look for in a Workout Onesie
Before you add to cart, here’s what actually matters:
Support
If you’re doing high-impact workouts (like running), look for a built-in bra or compressive fabric. Lower-impact workouts can get away with lighter support.
Fabric
Moisture-wicking, breathable fabrics are key, especially for cardio. Ribbed textures can also help disguise sweat.
Functionality
Pockets, adjustable straps, and ease of getting in and out (yes, bathroom breaks matter) can make or break your experience.
Activity Match
Not all onesies are created equal. Some are built for running, others for Pilates or lounging.
The Best Workout Onesies, Tested by Activity
Best for: Running + high-impact workouts
When I pulled this Bandit one piece out of the bag, I immediately knew the fabric was incredibly compressive because the garment was about the size of a toddler. After double checking it was in fact the correct size, I wiggled into the one piece, relieved once the straps were over my shoulders.
This was compressive in the way you want shapewear to be tight because you know it is doing its job. For the first time ever, my chest even felt supported in the built-in bra. I usually need to double up by wearing a sports bra under tops with a built-in bra. Another plus is that this particular one piece includes plenty of pockets.
I packed my fuel and phone, and I set off on seven miles in Central Park. It was an unseasonably warm day where I sweat like it was midsummer and because of the black ribbed fabric, no one could even tell. The built-in bra reduced bounce without being so tight that my shoulders were sore. I was truly shocked at how much I loved running in this garment. Also since it is one continuous garment, there are fewer seams and edges to ultimately cause any chafing.
My only complaint was that it was difficult to go to the bathroom, which is the only reason I did not wear it during my half marathon. Sure, $128 is not cheap but when I wear this one piece, it is the only item of clothing I am wearing for my run. Usually I wear shorts, a sports bra, and a top, which could easily exceed that total. This one piece absolutely sold me on the concept.
We like
- Compressive
- Ribbed fabric hides sweat
- Ample storage
- Supportive
We don't like
- None
Best for: Studio workouts + low-impact training
Split59 has long nailed soft, elevated basics, and this onesie is no exception. The fabric is buttery, breathable, and ideal for workouts where comfort matters just as much as performance.
It’s supportive enough for lighter workouts, though those with a larger chest may want extra support.
We like
- Soft and supportive fabric
- Built-in bra for smaller chest sizes
We don't like
- No pockets
- No contour seams
Best for: Pilates, lounging, and “clean girl” athleisure
437 is the epitome of the “clean girl Pilates” aesthetic that is all over TikTok. This studio inspired activewear brand comes in trendy colors like espresso and french blue and flattering minimalist silhouettes. While I would not run in this onesie due to the lack of a built-in bra and pockets, its seam details and low back are flattering. This option is ideal for yoga, barre, or Pilates.
I packed this for a quick weekend trip where space in my bag was limited, and wore it all weekend while hanging out and running to the grocery store. There is something so freeing about knowing I am fully covered and do not need to worry about anything riding up. I had no issues doing a virtual Pilates class, but for anything more intense, I would have to wear a sports bra for any support. At under $100, this would be a great gift for anyone who loves living in athleisure on the weekends.
We like
- Flattering seam details
- Tight but not uncomfortable
We don't like
- No pockets
- No built-in bra
- Not enough support to intense cardio
Best for: Reformer Pilates + low-impact workouts
FORM offers some of my favorite virtual Pilates classes. I know that if I only have thirty minutes I can still get in a workout that has me sweating. They also make tons of cute workout and lounge basics in flattering cuts and their halter onesie is no different. Granted I would not recommend doing any running in this, besides maybe to catch the train, but that does not mean it is not supportive enough for a reformer class. The welcomed two-layer bust panel gives the chest plenty of coverage, and the full length pants means you do not have to worry about anything riding up during leg circles and scissor kicks. Also the v-waist seam is incredibly flattering. Once it gets a little cooler, this will be an absolute staple in my rotation with a sweatshirt.
We like
We don't like
Best for: Running + high-impact workouts
When I pulled this Bandit one piece out of the bag, I immediately knew the fabric was incredibly compressive because the garment was about the size of a toddler. After double checking it was in fact the correct size, I wiggled into the one piece, relieved once the straps were over my shoulders.
This was compressive in the way you want shapewear to be tight because you know it is doing its job. For the first time ever, my chest even felt supported in the built-in bra. I usually need to double up by wearing a sports bra under tops with a built-in bra. Another plus is that this particular one piece includes plenty of pockets.
I packed my fuel and phone, and I set off on seven miles in Central Park. It was an unseasonably warm day where I sweat like it was midsummer and because of the black ribbed fabric, no one could even tell. The built-in bra reduced bounce without being so tight that my shoulders were sore. I was truly shocked at how much I loved running in this garment. Also since it is one continuous garment, there are fewer seams and edges to ultimately cause any chafing.
My only complaint was that it was difficult to go to the bathroom, which is the only reason I did not wear it during my half marathon. Sure, $128 is not cheap but when I wear this one piece, it is the only item of clothing I am wearing for my run. Usually I wear shorts, a sports bra, and a top, which could easily exceed that total. This one piece absolutely sold me on the concept.
We like
- Compressive
- Ribbed fabric hides sweat
- Ample storage
- Supportive
We don't like
- None
Best for: Studio workouts + low-impact training
Split59 has long nailed soft, elevated basics, and this onesie is no exception. The fabric is buttery, breathable, and ideal for workouts where comfort matters just as much as performance.
It’s supportive enough for lighter workouts, though those with a larger chest may want extra support.
We like
- Soft and supportive fabric
- Built-in bra for smaller chest sizes
We don't like
- No pockets
- No contour seams
Best for: Pilates, lounging, and “clean girl” athleisure
437 is the epitome of the “clean girl Pilates” aesthetic that is all over TikTok. This studio inspired activewear brand comes in trendy colors like espresso and french blue and flattering minimalist silhouettes. While I would not run in this onesie due to the lack of a built-in bra and pockets, its seam details and low back are flattering. This option is ideal for yoga, barre, or Pilates.
I packed this for a quick weekend trip where space in my bag was limited, and wore it all weekend while hanging out and running to the grocery store. There is something so freeing about knowing I am fully covered and do not need to worry about anything riding up. I had no issues doing a virtual Pilates class, but for anything more intense, I would have to wear a sports bra for any support. At under $100, this would be a great gift for anyone who loves living in athleisure on the weekends.
We like
- Flattering seam details
- Tight but not uncomfortable
We don't like
- No pockets
- No built-in bra
- Not enough support to intense cardio
Best for: Reformer Pilates + low-impact workouts
FORM offers some of my favorite virtual Pilates classes. I know that if I only have thirty minutes I can still get in a workout that has me sweating. They also make tons of cute workout and lounge basics in flattering cuts and their halter onesie is no different. Granted I would not recommend doing any running in this, besides maybe to catch the train, but that does not mean it is not supportive enough for a reformer class. The welcomed two-layer bust panel gives the chest plenty of coverage, and the full length pants means you do not have to worry about anything riding up during leg circles and scissor kicks. Also the v-waist seam is incredibly flattering. Once it gets a little cooler, this will be an absolute staple in my rotation with a sweatshirt.
We like
We don't like
Quick Breakdown: Which Onesie Should You Buy?
For Running: Bandit
For Pilates: FORM or 437
For Lounging + Errands: 437
For Soft, Everyday Workouts: Split59
Workout Onesie FAQs
Are workout onesies actually practical?
Yes, especially for workouts where constant adjusting is distracting. The one-piece design keeps everything in place and eliminates outfit planning.
Can you run in a workout onesie?
You can, but only if it has enough support. Look for compressive fabric, built-in bras, and functional details like pockets.
Are workout onesies flattering?
Very. Most are designed with contouring seams and compressive fabrics that create a streamlined silhouette.
What’s the biggest downside?
Bathroom breaks. It’s the one tradeoff but for many, the benefits outweigh it.
Why You Should Trust Us
At The Quality Edit, we test products in real-life scenarios. For this guide, each onesie was evaluated based on comfort, support, functionality, and versatility. The result: a curated list of pieces that actually hold up in motion.
