On an unseasonably hot Wednesday at the end of May, a little voice in my head was telling me to run faster. “It’s time to get your heart rate up,” she told me. This wasn’t my inner masochist, like it usually is. On this particular run, it was the voice of Vi, a digital assistant baked inside a pair of prototype in-ear headphones.

Vi is the first consumer product from wearable technology company LifeBeam, which has provided the tech backbone for products from Samsung, Under Armour, and JBL, among others. Now LifeBeam is partnering with Harman/Kardon for Vi, which debuts on Kickstarter on Wednesday.

Who is Vi?

At first glance, LifeBeam’s wrap-around headset resembles the LG Tone, a pair of Bluetooth headphones with neck controls for volume. And while Vi can be used to jam out on your daily commute like any other Bluetooth headphones, this product is like no other I’ve used.

LifeBeam You can listen to music, answer phone calls, and get workout inspiration from this pair of Bluetooth earbuds.

Vi combines a voice-activated digital assistant similar to Apple’s Siri or Amazon’s Alexa with the activity-tracking features of a Fitbit band in a pair of LG-like headphones. The earbuds have a slew of sensors packed inside that track your heart rate, heart rate variability, motion, and elevation while you’re running. While you’re running, Vi will analyze your heart rate and tell you to speed it up to really burn some fat. With Spotify and Apple Music integration, Vi will select up-tempo tunes with the right beats per minute to get your blood pumping, and you can ask her to skip songs. Instead of glancing at your wrist to see your stats, just ask Vi.

There is no shortage of smart assistants, but none of them are a suitable personal trainer. That’s where Vi comes in.

How it works

When you unbox the headphones, you’ll pair them to your iPhone or Android device like any other Bluetooth product. Then you’ll enter your goals in the Vi app. Do you want to lose weight? Do you want to maintain your current fitness level? Are you training for a race? With all of this info, plus the data Vi collects from your body, you’ll get incredibly personalized training advice—or so LifeBeam co-founder and CEO Omri Yoffe told me during my demo of Vi on a treadmill in an office building just off Park Avenue.

You can chat with Vi verbally or via SMS, same as you would a real life personal trainer. If the weather is crappy, Vi will text you some advice to adjust your normal outdoor workout to an indoor training session. You can message Vi about your sleep or what you’re eating. Vi is HealthKit-integrated so the assistant can read data from your other health apps if you grant access. Unlike an actual fitness coach, Vi won’t admonish you for skipping workouts or make you run stairs for eating poorly. It’s all about positive reinforcement, Yoffe told me.

LifeBeam Vi will text you with exercise advice just like a personal trainer would.

First impressions

Before I hit the treadmill with Vi’s voice in my ear, I was skeptical. “I’m not sure I would ever wear this running,” I wrote in my notes while watching another journalist take her turn on the treadmill. I’ve used a gazillion fitness trackers before, but none on my head.

I laced up some sneakers and hopped on the treadmill, earbuds snugly placed around my head. I started walking, and Vi told me my heart rate. Then she told me to increase my speed to get in the fat-burning zone.

We’re all used to talking to our devices by now, and chatting with Vi was no different. She reponds to various commands, but you’re not gonna have a full-blown conversation. (Not that you’d be able to do so while running anyway.) When she told me my heart rate, I could actually hear the thump of my heart beating in my ears, which was both cool and slightly strange. The earbuds themselves were more comfortable than the cheap sport pair I bought but almost never use. The Harman/Kardon sound was above average, as expected. I’m more interested in Vi’s possibilities, though. Yoffe told me that Vi is sort of like a fitness-minded version of Samantha from the Spike Jonze film Her. One day, LifeBeam’s headset will be a pair of wireless earbuds that you can chat with any time.

I only tested out a prototype of Vi for a few minutes, but I’m intrigued to see if the final product turns out to be the personal trainer I so desperately need but don’t want to pay for. At launch, the device will work best for runners, but software updates will expand Vi’s training capabilities to swimmers and bikers down the line. The headphones will run continuously for eight hours on a single charge—not bad for a pair of Bluetooth earbuds.

Vi is currently available to preorder on Kickstarter for $199 and will retail for $249. The device starts shipping in December.