I am contemplating taking a martial arts course (I'm leaning towards
Tae Kwon Do) - primarily for the
fitness aspect.  I'd also like to try something different than the
self-imposed gym grind for regular fitness. I am 34 years old, a
non-smoker and slim, though I
haven't exercised vigorously for about 6 months.  I played sports in
high school in college and since then have had stints of gym
memberships and regular jogging.  I live in Carroll Gardens, Brooklyn,
NY and work in Soho, Manhattan.  I usually work around 9-10 hours a
day.  I have two related questions: 1. what are the pros and cons of each
variation of martial arts (Karate, Tae Kwon Do, etc), and 2. where can
I take evening (or perhaps early morning) classes within a reasonable
distance to my home and work? Any anecdotal knowledge/experience of
said classes would also be appreciated.