I’ve been doing this for a week now and it’s been fine. The only problem is I’m not leaving my office at lunchtime, as I don’t have to wander down the hill to Subway, so I think “I’ll just finish this bit of work and then go for a quick walk…” and then, of course, it’s 3pm and it’s too late. I must balance making my lunch with still taking a break at lunchtime.