three times a week
A set phrase used to state a weekly frequency. Often appears in schedules, routines, or recommendations.
I go to the gym three times a week.
Please take this medicine three times a week.
Also means 'three times a week', but emphasizes 'every week' more explicitly.
Compound of 週 (しゅう, 'week') + 三 (さん, 'three') + 回 (かい, counter for occurrences).