Superior Laziness

Many people, if not of the Young Dude species, when entertaining the thought of doing martial art training, may be put off by the assumption of extreme physical demands relative to flexibility, endurance, strength and so on. They may also be put off by the thought of hard contact sparring. The good news is that, while any of the aforementioned kinds of training can be beneficial when properly done, they are not all usually needed at anywhere near maximal development. Endurance is important, but not "combat sport" endurance: most street fights are short, and while the adrenaline dump involved in a fight can be exhausting, there is not going to be a "round two" to worry about. As for flexibility, if you can get your foot up to average knee or thigh height comfortably, that's quite good enough. And strength, sure it's valuable, but if someone wanted to just be in decent to good general shape, that's fine as long as they understand that they need to be smarter and more efficient (read "nastier," e.g., jab the throat if possible rather than the nose) than the opponent. This is not just an optimistic theory, as it has actually panned out that way for a number of guys I know that did not have to endure hard contact sparring and are not exactly the greatest of physical specimens. The main point of all of this is that whatever shape someone is in, self-defense is a feasible possibility within their limitations.