depends on how your definition of "fit" is, really. Like, if you wanted to take Judo/Juijitsu, endurance is a big part in it[as it is every other art, I'm sure], but in my opinion, you'd want to start lifting and getting some bulk on ya if you wanna get good, but with TKD, especially if it's WTF[olympic-style] you'd want to try to work on your speed and not weightlift all that much[if you lift, you lose speed/flexibility in exchange for power] and I'd recommend looking at Collegiate Dojos for membership. Generally,[I don't know all the dojos in the world, so I can't say for sure, but mostly, this is true] collegiate clubs accept members that aren't students and are much cheaper[private clubs=$70-120 a month/collegiate clubs=$60-100 a SEMESTER], and aren't hung up about making money, like a lot of private dojos. [But, I'm in a dojo outside of school, so there are exceptions.] And they offer a lot of variety on campus - for instance, U of I Champaigne in Illinois has ~40 martial arts clubs on campus, and there are collegiate competitions [if you're into that kinda thing]. Personally, I want to take TaiChi[stop laughing], but they don't teach the right style here in the US, apprently. If you want to learn some straigt-up fighting, take Wing Chun, that's what Bruce Lee learned when he was young.