Another article in the NYT (subscription required) telling us what is blindingly obvious...but still needs to be pointed out. That we can do better work if we take breaks—you "can't be expected to lift weights all day" as Gloria Mark puts it in the article.
It reminds me of what Rich Hickey (the man behind the Clojure programming language) calls "hammock-driven development." We all know it...the best ideas come when you're switched off, taking a snooze in your hammock...see Hickey's full talk here.