Incidental exercise is the stuff you do when you don’t even mean to do exercise. Easy things to do include taking the stairs, not the elevator (which always takes ages to get to your floor anyway), getting off the bus/train a stop early and walking the rest of the way, or popping into your colleague’s pod to ask a question instead of flicking them an email or calling them (you’ll probably get a quicker answer too!). I would also recommend having standing meetings or introducing walking meetings to ensure you’re not in the same position at your desk all day. Also don’t keep a jug of water at your desk, just keep a cup and get up to fill it every time you want a glass of water–this will ensure you get to move around as well.