phase.fitness plans your training and runs it — and then gets out of the way, into the app you already log in and onto the watch you already wear. Here is exactly what travels, which way, and where it doesn't need to.
All three are written by the AI into your phases, and all three can be run in the built-in player — on a phone at the rack, or a laptop on the kitchen table. What follows is the second half of the journey: where a session also goes once it exists.
| Session | GarminWatch | Intervals.icuEndurance | HevyStrength | LiftosaurStrength |
|---|---|---|---|---|
Strength Barbell, dumbbell and machine work, periodized across your phases. | Sent and returned Sets and reps on the watch | Comes back only Counted in your load | Sent and returned | Sent and returned |
Cardio Structured intervals with heart-rate and power targets. | Sent and returned Six sports by name, the rest as generic cardio | Sent and returned Intervals and zones intact | Strength apps — your cardio goes to Garmin or Intervals instead | |
Calisthenics Skill work toward a movement: its own catalogue, roadmaps, holds and progressions. | Built-in player — no exercise catalogue out there has a tuck front lever, so there is nothing to send | |||
These arrive with their own sport, so the watch counts laps and zones properly: Running, Cycling, Swimming, Rowing, Walking, Hiking. The rest — triathlon, kayaking, cross-country skiing, mountaineering — arrive as a generic cardio workout: the session is there, the label is less precise.
A front lever isn’t a movement Hevy or Garmin know about — their exercise sets are built around barbells and heart rates. So a calisthenics session has nowhere to be sent, and doesn’t need one: the player walks you through the holds and the progressions, and the session counts in your program exactly like the others. The roadmap for the skill is the thing doing the work, and it lives here.
Everything below lands in one place, and that one place is what the AI reads when it writes your next block — whichever app it came from.
| Source | Direction | What it brings |
|---|---|---|
| Garmin | Comes back only |
|
| Strava | Comes back only |
Receive only — Strava has no way for us to send a planned workout back. |
| Intervals.icu | Comes back only |
Also the way Apple Health data reaches phase.fitness. |
| Hevy | Comes back only |
|
| Liftosaur | Comes back only |
Mutually exclusive with Hevy — you connect one or the other. |
You don't have to change app to train with a real program. Connect one, or all of them, and phase.fitness works around what you already do.
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