Leaf for Mac · ERG training over Bluetooth FTMS
Structured training, set in ink.
Leaf is a native macOS app that drives your smart trainer in ERG mode. Import a workout, clip in, and do the work while the trainer holds the target for you.
Sweet Spot 4×12
ERG · Interval 3/8 Bias 100%The Ride Sheet: live power, cadence, and heart rate at 1 Hz while the trainer holds the target.
What's on the sheet
From workout file to FIT file, without leaving your Mac.
ERG that actually holds
Leaf requests FTMS control only once the trainer is listening, and re-sends the target if permission ever drops. If a device disconnects mid-ride, it reconnects on its own.
Bring your library
Import .zwo, .erg, and .mrc files, or ride the built-in set. Ramps, steady states, and percent-of-FTP or absolute-watt targets all resolve correctly.
Bias and skip, on the fly
On a rough day, nudge the whole workout's intensity down a few percent, or skip a segment entirely. The trainer settles on the new target within a second.
History and FIT export
Every ride is stored locally and exports as a standard .fit file, ready for any platform that reads one.
intervals.icu, built in
Upload rides and read your fitness, fatigue, and form straight back into Leaf's analysis view.
A voice in the room
A deterministic in-ride coach speaks only when it has something useful to say: an interval about to start, power fading off target, the final push. The voice is neural and entirely on-device, and a calm chime turns the page between blocks.
Seven plans, grounded in the literature
From Metabolic Health & Weight Loss to Criterium Prep: periodized multi-week plans built on published training research, with recovery weeks that are actually lighter and hard days that never stack.
Reads your recovery
Weight, resting heart rate, and HRV flow in from Apple Health to inform the plan — advisory only, never auto-piloting your training. Outdoor rides and gym sessions count toward your load too — never double-counted.
Your data stays yours
Rides live on your Mac. Health data never leaves your devices and your private iCloud — not to AI providers, not to anyone's server. No account, nothing to sign up for.
The plan brain
The AI coaches. It never steers.
Leaf's plan brain watches your training and suggests what comes next. Every change moves through the same quiet loop, page by page.
The model reads your recent rides and drafts a change: an easier week, a swapped workout, a nudged target.
A deterministic rules engine on your Mac tests the draft against hard training limits before it can touch the plan.
You ride the updated plan. Only the ride engine talks to the trainer, holding each interval to target.
The ride lands in your history, the plan brain reads the result, and the loop starts again.
The Leaf rule: the model suggests and observes. It has no path to your trainer's resistance.
Leaf for iPhone · in the workshop
The same calm, in your jersey pocket.
Leaf for iPhone brings the Ride Sheet to the trainer that isn't next to a desk. Start today's planned workout, glance at live watts, and sync your history with the Mac app.
The full instrument: ERG control, plans, analysis, and the coach.
BetaRide and review anywhere. Shares the plan brain with the Mac.
In developmentTurns the watch you're already wearing into a standard heart-rate strap. One less thing to find, charge, and wet before you clip in.
BetaAn e-paper display for your handlebars. See below.
PrototypeLeaf Sheet · hardware prototype
Your next interval, on actual e-paper.
A 4.2-inch e-ink display that clamps to your handlebars and pairs with Leaf. The panel reads like paper whether the light comes from the morning sun or a shop lamp, and it runs for weeks on a charge. It shows the ride in front of you and nothing else.
Tilt it with your cursor ·
Status: prototype. The Sheet exists as a bench build around a stock 4.2″ panel. Want one when it's real? Say hello: hello@leafapp.ink.