Feif Un:
“(provided it isn’t against halachah)”
But Zumba is against halacha; that’s the point.
“Variety is the spice of life”, goes the expression. That does not mattir wife-swapping CH”V. (It’s like wanting to be cultural and modern so – completely contrary to Rav JB’s wishes, too – we trample on the Torah and attend Broadway shows to do so.)
But that’s not the point; Zumba is anyways not uniquely “marriage-enhancing” any more than any other aveira and/or a muttar form of exercise might be.
Music is an expression of the soul. There is no way listening to that kind of music (Latin) is good for your neshama. And I’d be embarrassed if anyone I knew went to Zumba.