Probably the 'not very fit' category for me. Back when i was about 14/15, I was dead skinny, although still not particularly fit. Then, when I got to 17/18, I started to drink from time to time, and I passed my driving test, so i stopped walking places, and my bike went into permanent hiding.
Since last summer though, i've joined a gym, and while I don't have the time or commitment to go more than once a week most of the time, its improved my fitness, and improved my physique a bit. Sadly, since christmas, due to various things, like bad backs, and illnesses, i've managed the gym once, and my fitness has gone again, as running for a train in London today proved to me. Although my chest's still a bit off from being ill, so that undoubtedly didn't help!