Using a heart rate monitor in the pool has never been ideal because looking down at your wrist for a reading means interrupting your stroke. With this inconvenience in mind, Finis designed an underwater device that uses bone conduction technology (the same used for waterproof MP3 players) to audibly give you a real-time heart rate reading. You simply clip a sensor to your ear like an earring and slide the AquaPulse onto your goggle strap. You can opt for announcements every 10 seconds up to five minutes, and the volume is easily adjustable. It plugs into a USB port to recharge.
Be sure to figure out the controls before starting your swim, because—although there are only four—the buttons aren’t labeled. I first used it while cooling down after a tough set, and it was satisfying to hear “130” and know my heart rate had properly lowered. The device works best when it’s right on your cheekbone, otherwise the sound is a little muffled and tough to hear.
I’d recommend the AquaPulse for: (1) newbies trying to figure out “easy” vs. “hard” ranges; (2) experienced athletes who are curious about heart rate in the pool or need an extra push to swim within a certain range; or (3) long-distance swimmers who want to keep a steady pace.