istrenirati

1. (of a person, an animal) to train
   Istrenirao je psa da donosi novine. — He trained the dog to fetch the newspaper.
   Novi trener je odlično istrenirao ekipu. — The new coach trained the team really well.
2. (of a skill, body part) to train; to build up
   Za tri meseca sam istrenirala noge. — In three months I built up my leg muscles.
   Sudoku pomaže da istreniraš pamćenje. — Sudoku helps you train your memory.

The imperfective is trenirati.