Workouts belong to one client, so reusing work means copying it. Basecamp gives you two clipboards rather than one, and knowing that saves a lot of rebuilding.
Copying a whole workout
Copy workout, switch to another client, Paste workout. The confirmation names what you copied, and pasting tells you it worked. The exercises come with it.
Copying a single exercise
A separate action with a separate clipboard: Copy exercise, then Paste exercise into this workout. This is the one that does not exist on the phone, and it is the more useful of the two day to day.
It is how you move a well-built exercise (the one with the right cues, the right units and a video already attached) into somebody else's workout without rebuilding it field by field. Over a roster, that is where the time goes.
The two clipboards are independent, so you can hold a workout and an exercise at the same time.
They expire
Both are temporary. Leave one too long and you are told plainly: the copied workout expired, or the copied exercise expired, copy it again. Nothing is lost; the original is untouched.
There is a Remove copied workout and Remove copied exercise control for clearing one deliberately, which is worth using when you have finished a run of pasting rather than leaving something stale on the clipboard.
Because each holds one item, rolling a workout out to six clients is six round trips. Do them in one sitting.
A copy is a starting point
It arrives carrying loads, rep targets and notes chosen for somebody else. Nothing in it is adjusted for the client you pasted it into.
Go through what you pasted and check the weights, the rep ranges and anything in the notes that referred to the original client. The exercise selection is the reusable part; the numbers rarely are.
Duplicating within one client
The same mechanism works inside one program. It is useful when next block is last block with the loads moved on. Copy, paste into the same client, rename, and edit from there.