As long as you're wearing the stuff in a way that makes it look like you care about your appearance. A lot of guys, like myself, would rather have a girl like that than one that is always wearing the classic "hot" girl clothes. It shows that you probably like sports and like doing things which a lot of athletic guys like.
He's got to remember you're a girl hunny. You need to flaunt your body sometimes.
Guys want to see your figure. Wear clothes that show off your figure. Generally, sports clothes aren't made to flatter a girl's figure, they're made to be comfy when playing sports.
I recently started dressing in sexier, guy-friendly clothing, and this one guy can't get enough of me. He told me flat out he'd laugh if I wore a hoodie. He said it would look like I don't care about myself if I dressed like that.
It's up to you... but personally I like that this guy can't get enough of me, so I'm going to keep wearing sexier clothing.