If you find that your interval blocks are too short or too long during your FulGaz workout, it is likely that your ride mode is set to either reactive or challenge.
For workouts in FulGaz, please ensure you have selected STEADY mode.
Riding in steady mode keeps the video speed locked in, thus keeping the interval lengths (and overall workout length) correct. To set your ride mode, click on the settings "cog" in the top right corner of the main ride screen.
Under Ride Modes, select STEADY from the three modes.
Riding in REACTIVE mode during a workout will mean the video speed is constantly changing, this will affect the length of any intervals.