Derny › Ellipticals
Ellipticals
Derny connects to your elliptical over Bluetooth and reads your heart rate as you go. When your heart rate climbs past where the workout wants it, the target comes down. As you recover, it builds again. The workout follows your body instead of a fixed script.
How it works
Ellipticals differ in what they let an app control. Derny checks when it connects and uses whatever your machine offers.
Derny sets the elliptical’s target power, and the resistance adjusts on its own to hold it. You just keep moving.
The elliptical doesn’t take a power target, so Derny shows you the target and you set the resistance yourself.
Derny can read the elliptical’s power but can’t control it. You see your target, your power and the difference, and set the resistance yourself.
In every case your heart rate is what moves the target. Derny holds back the next increase until you’ve caught up with the current one, so the target never runs away from you.
Compatibility
Derny talks to ellipticals and cross trainers through FTMS, the open Bluetooth fitness machine standard. If your elliptical pairs with other training apps over Bluetooth and shows its power or speed there, it very likely speaks FTMS.
Ellipticals are new in the beta. If yours doesn’t behave the way this page says, send the make and model to [email protected].
Workouts
You hold one steady heart rate, well under your max. Derny eases the effort as you tire so you can keep holding it.
Harder sessions built around how your heart responds. Derny offers the ones your elliptical can run once it knows what the machine reports.
Record with no targets, or build your own workout with power targets and heart-rate rules, in the app or by chatting with Claude or ChatGPT.
Finished workouts upload to Strava and save to Apple Health on iPhone or Health Connect on Android. See all workouts.
Questions people ask
Derny does this on ellipticals that speak FTMS, the Bluetooth fitness machine standard. If your elliptical takes a power target, Derny sets the watts from your heart rate and the resistance follows. If it doesn’t, Derny shows the target and you set the resistance yourself.
Ellipticals and cross trainers that speak FTMS over Bluetooth. Machines that only use their maker’s own protocol, and ANT+ connections, aren’t supported.
Yes. Connect Strava once and every finished elliptical workout uploads on its own. Derny also saves it to Apple Health on iPhone or Health Connect on Android.
For the adaptive workouts, yes: any standard Bluetooth heart-rate strap works, or an Apple Watch running the Derny watch app on iPhone.
Try it
The beta is live on iPhone through TestFlight and on Android through Google Play. Your invite arrives by email.