The purpose of the active breaks is to remove enough lactic acid to be able to complete 4 x 4 minute intervals at the correct intensity level.
If you do not remove enough lactic acid, you will not be able to complete the session at the correct level. Even if you don't know the lactic acid, it's there. To remove sufficient lactic acid, the active breaks should be a minimum of 3 minutes. It is also possible to increase the length of the active breaks, but they should not be longer than 6 minutes.
Adjust the active breaks according to your needs
In Myworkout GO, the active breaks are set to 3 minutes when you train on a treadmill or machine. Outdoors, the active breaks are set to 4 minutes - this is to give you time to get down the hill. If you want longer/shorter breaks, you can change this yourself in the settings in the app.