Before you move anything
Decide what actually has to come with you. In practice it is three things: who your clients are, what they are doing now, and what they are paying. Four years of completed sessions feel precious and are almost never opened again. Bring the live roster; archive the rest as a file you keep, not as a migration you perform.
Pick a cutover date and tell people. A migration that runs in parallel with the old system "for a while" runs in parallel forever, and every client learns that the new app is optional. One date, announced a week ahead, does more than any feature.
Do it between blocks. The natural seam is the end of a training block, not the middle of week three.
Step 1 — Bring the roster
Names, contact addresses, and the one or two facts you actually use — goal, training days, anything medical you must not forget. Not the whole spreadsheet.
Every client gets an invitation to the app. Expect the invitations to go out over a couple of days rather than all at once: a client who installs the app the same evening they hear from you is a client who is already using it by the weekend.
Step 2 — Rebuild the current block as a template
Do not port the whole library. Take the block your clients are on now, rebuild it once as a template, and assign it. Rebuilding one block is an afternoon; porting a library of forty is a fortnight and most of it was never going to be used again.
Prescribe against percentages or RPE rather than fixed loads while you are in there — it is the moment the template stops being a copy of a spreadsheet and starts being reusable. There is more on this in the programme templates guide.
Step 3 — Move the conversation
This is the step people skip and the one that decides whether the migration holds. As long as clients can still message you where they always did, they will, and the app stays half-used.
Say it plainly, once: from the cutover date, training questions go in the app. Keep the old channel for anything personal if you want to — but the training thread moves, and it moves on a date.
Step 4 — Move the money last
Get the training working first. Once clients are logging sessions, move subscriptions and invoicing over at the next billing cycle, so nobody is charged twice and nobody has a gap.
What to expect
The first week is the whole cost. Most coaches are through it in an afternoon of setup plus a week of clients installing the app and asking where things are.
Adoption is not instant and that is normal. A handful of clients will need a second nudge. A short message that names what they are missing — "your Thursday session is in the app" — works better than another invitation email.
Keep your old files. Export whatever you are leaving and keep it somewhere you control. You will almost never open it, and you will be glad it exists.
Getting help
On Team plans we do the import with you. On any plan, contact@agonos.app will get you a person who has done this before — send a sample of what you are moving from and we will tell you honestly what is worth bringing.