Evening hours between 4pm - 8pm during weekdays are normally filled with 30-40 people, other times are less busy.
This would be your go to gym if you do not need swimming pool. It has most of the tools and machines you need for a good workout, no skipping ropes nor water fountain though. It has 3 massage chairs and 2 massage beds for black memberships (9.99 bi-weekly).
Although the gym operates 24/7, you probably will have a tough time entering after mall hours since it is located inside the mall entrance.