I do about 15 minutes on the exercise bike and 5 or 6 sets of exercises with a kettlebell. I divide and alternate between sets, though, so it looks something like this: 3 mins on the bike high-intensity, break for a minute, a set with the kettlebell, break for a minute, back onto the bike for another 3 mins, so on and so forth.
I have no illusions that this is a comprehensive routine for weight loss or general health, but it keeps me from degrading into an entirely useless lump of fat that would inevitably fuse with my computer at the molecular level.
