en pleine forme
You're certainly looking fit as a fiddle today.
Tu as vraiment l’air en pleine forme aujourd’hui.
Tom seems to be as fit as a fiddle.
Tom semble être en pleine forme.
Your old lady will get you fit as a fiddle, without a cast.
Ta femme te remettra en pleine forme, sans plâtre.
— The Diamond Arm (1969)
Fit as a fiddle.
En pleine forme.
— Office Romance (1977)