Sports bras have come a long way since the ’70s, when amateur runner Lisa Lindahl made the first one by sewing two jock straps together. (Seriously.) We now have our pick of zip-front options, bold patterns and colors, and long-line crops that double as going-out tops, all of which are way more comfortable, cute, and supportive than their predecessors from even 10 years ago. But the latest addition to the elevated sports-bra boom is one that feels a little counterintuitive from a performance perspective: single-shoulder styles.
I first noticed this look on a few of my favorite fitness app trainers, and I was instantly shook. How were they avoiding nip slips as they cycled through burpees and Arnold presses? Could one shoulder sports bras possibly hold up boobs that are bigger than an A-cup? And wouldn’t that one strap dig into the shoulder, given that it’s doing the work of two?
To find out, I reached out to Avocado activewear—the brand responsible for the one-shoulder Mercury bra ($50) I kept seeing onscreen during my at-home workouts. Although it may look like a flash-in-the-pan trend piece, creative director Jessica Laursen says the Mercury is actually part of Avocado’s core assortment and is a firm customer favorite thanks to the bra’s seamless, yet supportive construction.
“The stitch composition is body-mapped, meaning that each type of stitch is placed specifically in order to create a better fit that perfectly hugs a woman’s body,” she says. The Mercury is made from double layers of sweat-wicking fabric, which means there are actually two straps on the left side of the bra. It also has subtly shaped cups, which further help hold the girls in place, and boasts four-way stretch technology. According to Laursen, this helps the one-sided straps “move with you and not off you” while keeping the bra secure around your torso.
Although the Mercury bra is recommended for low-impact activities like yoga, Pilates, and barre, I decided to give it the ultimate test and try it out during a HIIT workout. When I first put it on, I was impressed by how weightless it felt and was pleased to see that uniboob wasn’t an issue. During the workout, I initially felt like a flashing risk every time I lifted my arms overhead or did any kind of plyometric move, but my anxiety abated once I confirmed that the strapless side of the bra was staying put no matter what. I did notice that my upper boob was spilling over a bit around the armpit of the bra’s strapless side, but this is the case for me with most sports bras thanks to my breast shape—a strap usually just hides it better.
My colleague, Zoe, had a similarly uneventful experience when she worked out in the Mercury Bra. “I did The Class in it the other day and it was fine,” she says. (If you’re not familiar, The Class is another vigorous cardio workout with lots of arms-overhead movements.) That being said, we both coincidentally wear a size 32C, so someone over a D-cup might have a different experience. It’s also worth noting that the Mercury bra only goes up to a size 12 (M/L), although Avocado is currently developing the style in an XL, which will fit up to size 16.
Long story short, I was comfortable enough in a single-shoulder sports bra to make it a permanent fixture in my top drawer, although I’ll stick to wearing it as directed—for low-impact workouts. It’s also more of a special-occasion sports bra that demands to be seen, rather than something you’d hide under a t-shirt or wear to work out at home. But honestly, how great is it that we live in an era in which “special-occasion sports bras” are a thing?
These genius dressing-room tips will help you avoid sports bra-related wardrobe malfunctions during your workouts. And here are the best sports bras for those with DD-cups and above, according to the women who love them.