Always on
It never asks you to start it.
No session button, no reminder to put it on, no nightly charge. It reads continuously from the moment you fasten it, which is the only way a baseline that means anything gets built.
Terrifit V1
Stop guessing how hard to train
V1 reads your heart rate, sleep and recovery 24 hours a day. Every morning the app tells you how much your body can handle, and shows you the arithmetic it used. There is no screen to check and nothing to switch on.
TERRIFIT BAND 360°Ember
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From $229
Hardware comes next. Start with the app today.
15daysBattery on one charge
24/7Continuous heart rate
ECG+ PPGTwo ways of reading your heart
5coloursWoven straps, swapped by hand
Fifteen days
Charge it twice a month.
Two weeks of continuous heart rate on one charge. Long enough that you stop thinking about the battery, which is the point — a band on a charger measures nothing.
ECG and PPG
Two ways of reading the same heart.
Optical sensing runs all day. A second electrode records a single-lead ECG trace when you rest a fingertip on it. Recording, not diagnosing — if something looks unusual, the app tells you to see somebody who can actually say.
No screen
Nothing to look at.
There is no display, no notification, no buzz on your wrist mid-set. The band is a sensor. The reading, and the reasoning behind it, belong on a screen you were going to look at anyway.
Woven
Made to be worn, not stored.
Two colours of yarn woven together rather than a single flat dye. It takes sweat and chlorine without fading, dries flat in about twenty minutes, and does not look like gym equipment at a dinner.
Your numbers
Every score opens up.
Tap any figure and you get the readings behind it, the baseline each was measured against, how much of the score it carried, and what the day was missing. No other band shows you its working.
It measures. The app explains.
Five colours
Straps that are woven, not printed
Each strap is woven from two colours of yarn instead of being dyed a single flat colour. It looks different as the light moves across it, it hides the scuffs a training week puts on a wearable, and it won't fade the way a printed band does after a few months of chlorine and sweat.
Every V1 comes with one strap. Changing it takes a few seconds and you don't need a tool.
What it tracks
It's reading you the whole time
Five LEDs and four sensors take a reading a hundred times a second, awake or asleep, in the gym or in a meeting. You never have to start a session or remember to stop one.
- Heart rate
All day and all night, not just during workouts
- Heart rate variability
Measured in your deepest sleep, which is when the number actually means something
- Breathing rate
Breaths per minute overnight. It's usually the first thing that moves when you're coming down with something
- Blood oxygen
Overnight SpO₂, and how you're adjusting if you're training at altitude
- Skin temperature
Compared against your own baseline rather than an average of everybody else
- Sleep
Light, deep and REM, plus how long you were actually awake, against how much sleep you needed
- Strain
How much work your heart did today, on a 0 to 21 scale
- Recovery
One score each morning, worked out from your HRV, resting heart rate, sleep and breathing rate
- Movement
A six-axis accelerometer and gyroscope, for activity detection, sleep staging and how much of the day you actually moved
- Automatic sessions
It works out you have started training and logs it. Over forty activities recognised
A normal day
Four times a day it's worth looking
You don't need to check the app constantly. These are the moments the band actually changes what you'd do.
- 06:40Recovery score
It's waiting for you when you wake up, and it already knows what last night did to you.
- 12:00Today's target
How much training your body can take today, based on the recovery you actually have rather than the plan you wrote on Sunday.
- 17:30During the session
Live heart rate and strain on your phone, and rest timers that start when the band sees you stop.
- 22:50When to go to bed
The bedtime that gets you to tomorrow's target, adjusted for how hard you just trained.
Battery
Two weeks and then some, between charges
Two weeks is the point where you stop thinking about charging a wearable and just wear it. When it does need power, the PowerPack clips on and charges it while it's still on your wrist, so you don't lose a night of sleep data.
15 daysPer charge
With continuous heart rate monitoring running the whole time.
30+ daysIn the PowerPack
A wireless battery that clips on and tops up V1 while you're wearing it.
~2 hoursEmpty to full
Plug it into USB-C and one charge covers a fortnight.
No gapsIn your data
Because you never take it off, your sleep and recovery baselines stay intact.
Water and sweat
You can swim in it, shower in it and sweat all over it
V1 is IP68 rated, so rain, sweat and the shower are fine. It is not a dive watch — take it off before you swim laps or get in the sea.
IP68 sealed
Rain, sweat and the shower are fine. Take it off before you swim laps or get in the sea.
Sweat and salt
The weave lets sweat through instead of holding onto it, and it dries flat in about twenty minutes.
Sauna and cold plunge
Rated from −20 °C to 60 °C, so recovery sessions get logged like anything else.
Chlorine won't wreck it
No fading, no stiffening and no smell after a full season of lane swimming.
Works with your other apps
Your data goes wherever you already keep it
V1 writes into Apple Health and Google Health Connect on its own, so anything on your phone that reads those can read your band. The rest connect directly, and you can switch any of them off in one tap.
Both directions. Workouts, sleep, heart rate, HRV and breathing rate.
Syncs both ways with any Android app that supports it.
Sessions, sleep and daily activity.
Posts your sessions automatically with heart rate and strain attached.
Puts V1 recovery next to your Garmin activity history.
Live strain on your wrist while you're training.
Sends finished sessions into your coach's plan.
Class heart rate and strain end up on the same timeline.
Broadcasts your heart rate straight into the ride.
Brings in sleep from a ring you already own.
Imports your history if you're switching over.
Puts what you ate next to the work you actually did.
Apple Health is live in the app today. Health Connect and the direct connections below are being built and will arrive before the first bands ship — we will say here if any of them slips.
You can export everything as a CSV whenever you want. We don't sell health data, and no coach or creator sees any of it unless you specifically share it with them.
In the box
What you actually get
- The V1 sensor
Five-LED optical array, accelerometer, gyroscope and skin temperature sensor
- A woven strap
In the colour you pick, sized to your wrist
- V1 PowerPack
The wireless charger that works while you're wearing the band
- USB-C cable
One metre, braided
- First month of membership
Maps, your full history and creator channels included
Specifications
The full spec sheet
Sensors
- Optical
- PPG heart-rate sensor
- Motion
- 3-axis accelerometer
- Temperature
- Skin temperature
- Blood oxygen
- Overnight SpO₂
Power
- Battery life
- 180 mAh, over 15 days
- Charging
- Magnetic charger
- Cable
- USB-C
Build
- Waterproofing
- IP68
- Strap
- Woven nylon and elastane
Connectivity
- Wireless
- Bluetooth LE 5.4
- Offline storage
- Up to 30 days
- Phones
- iOS and Android
- Export
- CSV, Apple Health, Health Connect
- Updates
- Over the air
Your health data stays yours
Everything the band measures is private unless you decide otherwise. Coaches and creators see nothing until you share it with them, you can take that back in one tap, and we don't sell health data to anybody.
Read how we handle your dataFirst production run
Put it on and forget about it
Pre-orders ship in the order they came in from November 2027, and the founding price holds for the whole first run.