Indoor cycling for Android
Gradient connects to your smart trainer over Bluetooth and sets the resistance for you: structured workouts held in ERG, rides by heart rate, and real climbs and classics with every change of grade.
Gradient is in early access: install it from Google Play and get every update as it comes. Android 12 or later. Tried it? Tell us what to build next.
Pick a workout and pedal. Gradient tells the trainer what to do, step by step, and shows you exactly where you are in it.
The trainer holds each step's power whatever your cadence or gear. You see the step, its target, the time left, what comes next, and the whole session in zone colors.
Ride by heart rate and Gradient sets the power that brings your heart into the zone and keeps it there. Because a heart lags behind the effort, it shows the heart rate you should expect by now, so you don't overshoot trying to catch up.
The trainer gets every change of grade, and your speed comes from your power, your weight and the road. The profile ahead is colored by grade, with the distance and the climbing left.
Power with its zone, cadence, speed, heart rate and the trainer's resistance, plus the route on a topographic map and the last five minutes as graphs. On a tablet in landscape your ride's numbers stay beside every page. The screen stays on while you ride.
Swipe to the last page and the route you're riding becomes a road in front of you, rising where the trainer gets harder. Simple on purpose, so it runs on any phone and keeps your eyes on the effort.
The road follows the route's map coordinates and its elevation: the hairpins of Alpe d'Huez, the climbs of Il Lombardia. Your power, cadence and heart rate stay above it, the grade, elevation and distance below.
Switch on the pacer and a rider in red sets off on the same road at a power you choose, a share of your FTP or a number of watts, with a head start. It weighs what you weigh and rides the same physics, so the gap is only about the watts. You see it in metres and seconds, a marker over its head even behind a hill, and a note when one of you passes the other and who reached the finish first.
Every choice in the 3D road comes from what it's for: showing you where the road goes and how hard it's about to get, on a phone that's already busy talking to your trainer.
Plain polygons and distance fog, like late-1990s games with their textures off, in a warm sepia. No game engine and nothing to download: the road is drawn with the same graphics as the rest of the app, in a sliver of each frame, so it runs on modest phones and works offline.
A real 5 % looks flat on a screen. So the road is drawn one and a half times steeper, the view tilts with the slope and the asphalt darkens the steeper it climbs: you see where the climb starts before your legs do. The numbers stay true.
Marker posts every 20 m, tufts of grass on the banks, patches in the asphalt and the centre line stream past close by, so even 9 km/h up a hairpin feels like progress.
The scenery is placed by the distance along the route, not at random. Ride a route again and the chimneys and the farmhouse are where you left them, so you learn it as you would a real climb.
Smooth while you ride, at 60 frames a second, and nothing at all when you stop: not a frame is drawn while you stand still.
Your speed, the pacer and the trainer's resistance come from the same model of the road: the grade, rolling and air resistance, your weight and your bike's. What you see is what your legs feel.
Every ride is saved as a FIT file, the format of Garmin's devices, every minute while you ride. Take it to any app that reads FIT, or open it in the free Rides page for graphs, zones and best efforts.
Standard Bluetooth profiles, so it isn't tied to one brand. Your sensors are remembered and connected again when you start.
Any trainer with Bluetooth FTMS (Fitness Machine Service), which most current trainers support, and Tacx trainers on older firmware.
Chest straps and armbands over Bluetooth, such as a Polar H10.
Power meters and cadence or speed sensors. When two measure the same thing, you choose which one the app uses.
Make routes and workouts for the app, and look back at what you rode. No account, nothing to install, and your files stay in your browser.
Click the map and the route follows the roads, with smoothed elevation and grades. Export a CSV for Gradient or a GPX for your Garmin, Wahoo or Karoo.
Plan a route →Build structured workouts from steps of power or heart rate: intervals, ladders or a template, then export them for the app.
Build a workout →Drop in the FIT files the app records: numbers, graphs, time in zones, best efforts, laps and a weekly history.
Open your rides →Gradient doesn't need the internet and doesn't track you. Your rides, workouts and settings stay on your phone.
Gradient