That’s something not within the scope of Intervals. There are plenty of other free and payed (low budget) apps for trainer control integrating with Intervals.
Just to name a few:
- Breakaway
- TrainerDay
- BikeTerra
- ICTrainer
- Auuki
- InCyclist
…
And I’m sure I’m unintentionally forgetting other ‘Intervals minded’ apps. I’m sure you will find something to your likings.