In a quest for balance

I see how i love it all yin. But how do I bring about some yang activities? I am finding myself rejecting anything that requires serious amount of effort. For example i object to going to a challenging yoga class, while I am happy to go to a dancing sort of class. But is what I feel comfortable with doing, the best criteria to make choices? Should I push myself or not?

I know that's something personal that's different for each, but what's your take?