As someone who is trained in research methods and the importance of empirical evidence I'm always on the lookout for what current research says about weight loss, healthy eating, weight maintenance, etc.
I came across this article today that discusses a research study that found couch potatoes who get 1-2 hours of moderate exercise a day are just as bad off as those who don't exercise at all when it comes to longevity. Essentially the more hours you sit, the less likely you will live as long. And here's the shocking part: that's true even if you freaking exercise for 2 hours of the day - if you sit for the rest of the day you a goner (especially if you sit longer than 8 hours a day). In this study, exercise didn't decrease sitting time.
Of course, the researchers say that exercise has other benefits (blood pressure, weight maintenance, etc.) so they aren't saying you might as well just sit down. But what they are saying is that you shouldn't fool yourself into thinking if you run 5 miles in the morning you can sit on your butt the rest of the day.
Now I don't know about you but I have a desk job. It's really hard to work at a computer standing up. I know there are people who have "standing desks" but that just seems kind of strange to me (and I'm pretty sure my work isn't going to install those any time soon). So what's a girl to do? The message I took away was keep up the daily exercise but try to make sure I get up frequently throughout the day.
I do take a 30 minute walk at lunch. I try to get up and walk to coworker's offices to ask questions instead of emailing. And I drink enough water to have to make a trip to the bathroom every hour or so (I know, TMI). Hopefully it's this extra effort to keep moving as often as possible throughout the day that will help keep the grim reaper away, at least until the zombie apocalypse. But that's a whole different issue.