This is the 8879th most frequent Russian word.
приобретенные
"Acquired" or "obtained."
In this sentence, 'приобретенные' is an adjective describing 'навыки' (skills), expressing that these skills were obtained or learned over time.
Опыт положительно влияет на приобретенные навыки.
Experience positively affects the acquired skills.
Here, 'приобретенными' is an adjective agreeing with 'знаниями' (knowledge), indicating that this knowledge was gained through study.
Она гордится приобретенными знаниями после окончания университета.
She is proud of the acquired knowledge after graduating from university.
'Приобретенным' refers to 'тренировкам' (training) as a participle, emphasizing the idea that the training was obtained and utilized effectively.