First off, putting the optical heart rate sensor on your forehead is supposed to be more accurate than conventional designs, according to the company, partly because there's less skin in the way. Your forehead also moves a lot less than your arm does during a workout, and that motion makes it harder to get a precise read. Sweat and muscle constriction also get in the way of an exact measurement. Because the Moov sweatband absorbs moisture and stays pretty firmly in place, these interferences are kept to a minimum, in theory making for better results.

In a recent demo, this was indeed effective. I placed my hand on my jugular while trying on a Moov HR sweatband and looked at the visualization of my pulse on an interface the company made for demo purposes. A bouncing dot plunged each time I felt my heart beating. I also watched as my pulse increased when I stood up and walked about after a period of sitting down.

That information is then sent to your phone, where Moov's voice-based AI coach will tell you what actions (burpee, jumping jack, etc.) to do and what cardio zone you're in. This is why the precision of your heart rate data is so important to Moov: If your readout is off, you could be exercising in a completely different zone than you need to. I also appreciated the app telling me (and showing me, with visual aids) exactly what to do -- kind of like following an aerobics video that knows what you're doing.

In addition to being accurate, the new placement also made more sense than I initially thought. After all, a lot of people already wear swim caps or sweatbands when they work out. The headbands are available in black and teal at launch, and the one I tried felt secure and didn't budge while I moved around a small room. It was, however, a bit of a hassle to get my bangs out of the way and make sure the heart rate sensor was sitting just above my eyebrows so it would work well.

The Moov HR Sweat and Swim are available for $60 each or $99 for both until Nov. 18th. After that, they'll cost $99 each. That's relatively affordable, considering most wrist-worn heart rate trackers, such as the Fitbit Charge 2, cost about $200. But those devices also do more than just monitor your pulse. Chest straps are cheaper, starting from $50 for one from Garmin, but they require a companion Garmin device, are unwieldy and move around a lot during a workout. The Moov HR specifically targets those who want super-accurate cardio info and don't mind buying a dedicated gadget to do that, and its seemingly precise measurements (from my brief time with it, at least) could win those people over.