Isn't it interesting, how certain people are quick to criticise the obese for being "lazy," but won't reveal their own exercise regime here
To be in good shape, I walk at least 30 minutes each day. Most days I walk for 40 minutes twice a day (to and from my place of work/study, which is up a steep hill!) In addition, I have a dance lesson once a week, and I do kick-aerobics, dance, or yoga, whenever I have time. I used to train martial arts every evening, but I can't at the moment

I try to stay active during the day - getting up from my desk every hour to get a drink or visit the library

This is important for your circulation and metabolism.