One of FitBit’s more useful features is its ability to automatically detect exercise. I think it uses a combination of your heart rate and how the device is moving.

The pattern of motion and heart rates must be categorised by FitBit so the app can tell the difference between “swimming” and “running”, etc.

It’s not a precise system though. Yesterday I went skating for a few hours, and then spent the afternoon working on my allotment.

I can see how walking and skating are similar. They both take relatively low amounts of effort and have a rhythmic stepping pattern.

Gardening and cycling though don’t seem that similar. Then I remembered I spent a while using my awesome battery powered rotavator to turn over some of the ground, and I guess the shaking of my arms and the effort of trying to stop the thing escaping looks a bit similar to a bike rolling along a dirt track.