wow, this thread is getting a bit nasty.
no one has any idea what is going on through that girl's head. chris, you have a good point and girl has a good point too. she could be interested and just has been extremely busy with training or shy, or she could be a people pleaser/attention whore like girl said.
girl tried explaining to you why a girl would be like that and it seemed like you were just ignoring her explanations...just because you don't understand it doesn't mean it's wrong. girls and guys think very differently so keep that in mind when you are getting advice from both men and women on this forum.
a woman like girl describes as being a people pleaser is someone who wants others to have a good opinion of them and has problems saying no, so they make excuses that someone would consider valid to get out of any commitments. an attention whore is someone who just likes getting attention from guys. a girl could be NOT interested in you, but maintain conversation and continue giving you false hopes just so that she can feel the pleasure of another guy being attracted to her. it's messed up and selfish, but it does exist, keep that in mind.
call one more time and tell her that you understand she is really busy and such, that your schedule is more flexible and that she should just give you a call when she is free and wants to hang out. the ball will be left in her court. if she calls you and schedules a date, then you'll know she was just busy or too shy to go out of her way those 2 weekends. if she doesn't call you and continues giving you the run around when you see each other at the gym, then you know she just likes the attention or isn't interested and just wants to remain friendly. at that point, just move on...