FTMS

What is FTMS?

FTMS stands for Fitness Machine Service. It is the Bluetooth standard that lets an app read a smart trainer and control its resistance, and it is the reason one trainer can work with many different apps.

The short version

The Bluetooth SIG, the group that runs the Bluetooth standard, published FTMS for fitness machines: smart trainers and indoor bikes, and also treadmills and rowing machines. A trainer with FTMS sends its numbers to an app several times a second and accepts instructions back. Because it's a shared standard, any app that supports FTMS works with any trainer that has it, whoever made the trainer.

What goes back and forth

The trainer sends power in watts, cadence, speed and distance. The app can send one of three things: a fixed resistance level, a target power (this is what apps call ERG mode), or a description of the road, meaning the gradient plus wind and rolling resistance. That last one is simulation mode. longvoie uses simulation mode, because it's the one that feels like a road.

FTMS and ANT+ FE-C

ANT+ FE-C does the same job over ANT+, a different kind of radio. On a computer it needs a USB dongle, and phones and browsers mostly can't use it. FTMS runs over Bluetooth, which every laptop and phone already has. Most trainers from the last few years support both, and some makers also have their own protocol alongside them.

Checking your trainer

The manual or the maker's app will say "FTMS" if it's there. Many trainers got it through a firmware update, so update yours first. Current trainers from Wahoo, Tacx, Elite, Saris and JetBlack have it, as does the Zwift Hub. More on trainers that work with longvoie.

A free app to try it with

longvoie is free and runs in Chrome or Edge. It connects to your trainer over FTMS and sends it the gradient of real roads, like Alpe d'Huez or Mont Ventoux, or of any GPX file you bring.

Questions

What does FTMS stand for?

Fitness Machine Service. It is the Bluetooth service for smart trainers, indoor bikes, treadmills and rowing machines.

Is FTMS the same as ANT+ FE-C?

They do the same job over different radios: FTMS over Bluetooth, FE-C over ANT+.

What is the difference between ERG and simulation mode?

In ERG mode the app picks a power and the trainer holds you to it, whatever your cadence. In simulation mode the app gives the trainer a gradient and it resists the way that road would.

Are there free FTMS apps?

Yes. longvoie is free and works with any FTMS trainer.