Recommendations for gym based work wear?

[StyleFlow]

Greetings,

I own a hot yoga/fitness studio and am looking for appropriate recommendations for daily attire.
I generally need clothes that are loose and comfortable. I often have to go into the hot room to adjust (95-105 degrees) to adjust equipment or grab an instructor.
It wouldn't be appropriate for me to wear a button down shirt, dress shoes. I'd look out of place.

I usually lean towards cargo pants and a black v-neck t-shirt and cool shoes.. But I want to by stylish. I don't want to wear Nike, under armor, etc.

So what does a man wear when he is moving around a hot yoga studio all day long?

ex: All my shoes (like John Varvatos style) have zippers so I can get in and out of them quickly..

Thanks