“Work out” is a phrasal verb with a couple of different meanings. Firstly it can mean to do some kind of intense exercise (workout is also often used as a noun meaning a sessions of exercise, for example: “I did a short workout before work”). “Work out” can also mean to find a solution to a problem. Both meanings for this phrasal verb could come up in all parts of the B2 First exam.
She used to work (2)…… for thirty minutes every day before work as she knew how important is was to do regular exercise.
John and Mark used to always exercise together on Saturday mornings.
John and Mark would ………………………… together on Saturday mornings