Eat, relax and enjoy

Hiring a personal trainer as a way to save money makes no sense, because most gyms require one to become a member before hiring a personal trainer, and limiting workout sessions to those involving a trainer means only working out once a week.
Not having a gym membership may save money in the short term, but also make it less likely that one will work out less often and less intensely. Trips to the gym (whether fancy or no-frills) that are part of a daily routine are more likely to be consistent in the long term.
Free passes are basically promotion, or advertising, by the gym, to encourage new customers, or as a courtesy to the friends or family of members who are in town for a few days and who want a place to work out. It's not free - someone has to pay the overhead at the gym (rent, employees, insurance) while she is working out there. Why should fee-paying members subsidize your blogger, who has no intention of purchasing a membership, and who is using the free passes intended to benefit our family or friends visiting town for a few days or to increase the gym membership and revenue? Apart from being cheap, it is also short-sighted: if she were to spend less time scrounging for free gym passes all over the city, she could spend more time working and generating income, which she could then use to pay honestly for the services she uses.