What you don’t want to know:

I know this is not nice reading for all of you sitting at work. I also know I’ve never been as out of shape (and frequently ill) as I was when I had a desk job – a real desk job, with 8hrs of computer work each day and only the occasional sprint to the coffee machine to break up the hours. So if you’re there too, make sure you do whatever you can to move those arms and legs – whenever you can!