Early hours are good, you would be surprised how many students wake up early to go to the gym though.
The Pulse opens typically at 6am. If you go real early, you can usually beat the rush of students that are sleeping in till 7-8.
Weekends seemed to be less busy as well when I was at Mac, typically because a number of students go home for the weekend. Less students - less busy.
Here are the hours of operation: