Sometimes you just want to train without following a routine. ＋ Quick workout, on Dashboard or Workouts, starts an empty session — add exercises as you go, from your phone or your watch, and keep adding through the whole session.
Anything you add mid-session shows up on both devices, so a set logged on the watch and an exercise added on the phone land in the same workout either way. Newly added exercises prefill their starting weight from the most recent time you actually logged that lift, so you're not starting from a guess.
When you finish, you're asked whether to save it as a routine. Saying yes turns exactly what you did — the exercises, sets, and weights you actually used — into a real, repeatable routine you can start again later. Saying no just keeps it as a one-off in your history.
A quick workout is logged under the name "Quick Workout" and, on its own, never advances any planned routine's targets — it's off-plan by design. Progressive overload only picks it up once you save it as a routine, and even then that first session can't advance the very targets it was used to create.
Related: "Logging a workout", "Picking an exercise", "How progressive overload works"