Applescripting Numbers to save, close and quit in an App instead of the Script Editor
You need to direct the save command to Numbers app...

This should work for you.

tell application "Numbers"
    save document 1 in POSIX file "/Users/name/Desktop/Workout.numbers"
    delay 0.1
    close document 1 
    delay 0.1
    quit
end tell


Or if you want to make the code a little prettier...  This should work also.

set saveToFolder to path to desktop folder as text
set numbersDocName to "Workout.numbers"
set numbersDoc to (saveToFolder &amp; numbersDocName)

tell application "Numbers"
    close document 1 saving yes saving in file numbersDoc
    delay 0.1
    quit
end tell