It looks like an ordinary sports bra (albeit a cute one), but the | Here's How to Seamlessly Track Your Heart Rate With Wearables | POPSUGAR Fitness Photo 7
Sports bra monitors heart rate with built-in heart monitor
Mocha Basic Seamless Padded Sports Bra | PrettyLittleThing USA
Adidas Powerreact Training Women's Medium-Support Bra | Bridge Street Town Centre
adidas Women's Running Medium Support Pocket Bra, Black, X-Small C at Amazon Women's Clothing store