Just 6 months after giving birth to Cristiano Ronaldo's kid ... Georgina Rodriguez is working out like a beast -- and looks damn good.
CR7's girlfriend was crushing a kettlebell workout in Madrid on Thursday -- while a personal trainer ran the session like a drill sergeant.
The 24-year-old gave birth to baby Alana Martina back in November ... just about 5 months after the birth of Ronaldo's twins from a surrogate mother.
Alana is Ronaldo's 4th kid -- he also has a 7-year-old son, Cristiano Ronaldo Jr.