The Portugal captain, who has missed Real's last four matches with knee and muscle problems in his left leg, is the top scorer in Europe's elite club competition this term with 14 goals, equalling the record for one edition.
"Cristiano Ronaldo ... completed the entire session with the group," Real, chasing a record-extending 10th continental crown, said on their website.
Wales winger Gareth Bale was unable to train due to a bout of flu, the club added without specifying whether he was expected to recover for the match at the Bernabeu.
The return leg is in Munich next week and the winners of the tie will play Atletico Madrid or Chelsea in the final in Lisbon on May 24.
- Sports & Recreation
- Cristiano Ronaldo