Does the FitBit Ultra work properly with an outdor bike ?

[Charlotte63]

Does the FitBit Ultra work properly with an outdor bike ? I have recently started using the FitBit Ultra. Mon- Thursday I do an eleven mile bike ride over a very hilly route and cycling in high gear most of the time. This means that the bike wheels are more resistant to turn and my legs move more slowly and cycling is much harder work and produces some quite fast times. However, by Friday I am tired and take it easy. I do a less hilly route but cycle in much lower gear and hence my time is much slower. However, where I am cycling in lower gear, although the bike does not go as fast my legs have less resistance and are going around twice as fast. The Fitbit Ultra always records that I do the most steps and hence burn the most calories on a Friday when I am actually taking it easy. Is this because the Fitbit does not recognise effort and time taken to cover a distance so is hence giving me a false reading ?

[JohnnyRow · Accepted solution]

Assuming you are referring to the Alta, without heart rate monitoring, it cannot detect how hard you are working, only the "steps" and estimates calories from steps. In the Fitbit models with heart rate sensors, including Alta HR and most later models, it would be looking at your heart rate to determine effort and thus calories.

Slightly off-topic, when I used to bike, I often read that it was generally better to stay in lower gears and pedal faster, partly for being easier on your knees.