RX
As Prescribed
Doing the workout exactly as written — same weights, same movements, no modifications.
What it means in a class
RX (short for the prescription symbol, ℞) means you completed the workout exactly as programmed: the prescribed loads, the prescribed movements, the prescribed reps. If you changed anything, you scaled.
RX is not the goal in itself. Intensity and good movement are the goal. Plenty of our fittest members scale workouts regularly because the scaled version gets them the intended stimulus — and that's the whole point.
On the whiteboard
"That was RX'd" — the workout was done exactly as written.