Really depends what part of town you want to be in - Louisville has a pretty great selection TBH. Derby City is off Dixie Highway, pretty deep in the southwestern part of the city. As said before they have great BJJ and striking instructors. Area 502 MMA is in the Iroquois area Triumph Combat off poplar level , newer and smaller gym but with lots of great experience. Real Fighters in J-Town is great for Dutch style kickboxing. Fight Factory in St Matthews does a good mix of bjj and striking Core Combat in the East End has boxing, bjj and Krav Maga. All of these spots cater to adults and kids and will definitely give you a great cardio kick.