Sorry to sound negative, and I am not sure what the demographics of your area are as well as your goals, so my post could be total garbage......but in my experience the greater profit potential is not with the 'hardcore' crowd, more the 'general population.' Best of luck with your new business venture in any case
Edit, forgot my point like a idiot, but I would go for not too much of a hardcore name, in case you ever want to change your target market.
no offense but i dont think he asked for your business opinion
in any case i think that there is room for bothe in the same gym have a sort of power room and a seperatearea for cardio as well as circuits
there are plenty of gyms with hardcore guys workingout harmoniously and inspiring the regular folk
you just have to accomidate bothe and have a good staff to make people feel comfortable thats where sales and personal trainers play an important role