Hello There,
I am a Female but not Dutch, but I can surely help you with your marketing task required as explained in your project desc.
I can create a new facebook account for this task and start liking following pages of fitness clubs which you would suggest me to e.g. Within particular area, some specific names, criterion etc.
And then can share you the screenshots with you.
Please let me know if you liked my idea, we can discuss more if you want.
Thanks!
Kalyani