Is successful, 7 letters
Makes a lot of headway, 7 letters
Makes a lot of progress, 7 letters
Makes good progress, 7 letters
Makes great progress, 7 letters
Succeeds, 7 letters
Balloons, 7 letters
Puts on pounds, 7 letters
Tones one's body, 7 letters
Breaks loose, 8 letters
Deserves a slap, perhaps, 9 letters