Since Dad lives nearby, could he take them one night a week and get them to school the next day? It would free up one morning for training.
Barring that, I'd go over the morning routine with them in detail the night before. Homework? Done. Clothes? Laid out. Breakfast? Ready to prepare - something that doesn't require cooking, of course. Cereal, maybe, or toaster waffles with PB&J. Lunches? Made ahead the night before and ready to go out the door. Backpacks? Loaded and ready by the door.
I think if they're used to getting up and ready to go by themselves -- maybe even do a trial run one morning, or let them start doing it all for themselves every morning, whether you're there or not -- they'd be okay.
I think my 12-year-old would still be in bed if I called after my workout.
Be really careful, though. Once upon a time I was a social worker in Florida and one of the things I learned there is that it is (was?) illegal for children under the age of 14 to stay home alone and unsupervised. (Not that people don't do it.)
Would a next-door neighbor check in with them in the morning to make sure they're up and fed?
Roxy
Getting in touch with my inner try-athlete.