Hi! Marathoner-in-training here. As someone who has *quite* a long way to go before I set off on the Staten Island bridge at the 2022 New York City Marathon, I've been pretty generous about treating myself to special activewear as a little motivator, if you will. One of my favorite things to purchase is one-piece styles [1], which not only make getting ready to work out easy but also don't distract you by riding up or rolling down while you exercise. That said, I've been on a mission to find the most comfortable and functional option for marathon training. My quest led me to Lululemon's new arrivals page and the SenseKnit Running One-Piece [2] ($198), which, in theory, checked off all of my boxes. The website marketed it as tight and body-contouring but breathable, sweat wicking, and long, with shorts that extend eight inches. I was sold on every detail, so I decided to take the plunge, adding my usual size six to cart. Check out my complete review ahead.

What I Like About This Running Onesie

Initially, my only hesitation in adding it to my shopping cart was that this onesie looks legit, like something a pro runner would slip into for a race worthy of the evening news. As someone who's just barely coming in at under nine minutes a mile, I feared that I'd look and feel like a fraud in this. But once I slipped it on, my fears were expelled. I knew I would want to live in it, let alone just wear it running. It really, truly feels like a second skin thanks to its ultra-stretchy combination of 75 percent nylon and 25 percent elastane. And when I run in it, the sleek, compressive material stays in place and keeps me focused, so I don't have to keep messing with them while running like I sometimes have to do with leggings.

Another thing I love is this one-piece's long length. I tend to gravitate towards leggings over running shorts [3] because I hate the feeling of my legs rubbing together. But this length lands right above my knee, so I can save my full-length running tights [4] for the fall and winter.

What's Worth Noting

My one and only complaint about this onesie is that none of its pockets are really ideal for holding a phone. It features a large pocket in the back, gel pockets at the chest, and a hidden pocket at the front waist, all of which are super convenient for small items like my ID, energy gels, and keys. Other than that, I have a feeling you'll be obsessed, too. After all, the reviews on Lululemon's section are similar to mine. One person who purchased a size 10 said: "I have tried pretty much all of the bodysuits that Lululemon has put out in the past few years. This is, by far, the best for my body type.

"Usually, I have issues in the bust area because I have a larger chest for my height but being able to leave the chest area unzipped is perfect."

Who Is This Running Onesie Best For?

This running one-piece is a must for runners of all skill levels. I regret being hesitant about buying it at all because — not to sound corny — it makes me look and feel stronger. And since running is such a mental sport, I'm convinced it's helped me maintain a quick mile pace. Now all I need is a second one because I've been washing and wearing it on repeat.

Additional Details

• This one-piece comes in sizes 0-20.
• This running one-piece comes in black and a purple color called "Charged Indigo."
• To keep it in optimal shape, machine wash in cold water and tumble dry on a low setting.
• The brand's SenseKnit fabric comes in other silhouettes, too, like the SenseKnit Running Tank Top [5] ($54, originally $78) and the SenseKnit Running High-Rise Short 10" [6] ($108).

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