I'd say it's much worse than that. If I stop to walk in a marathon, I can probably expect to run faster for a little bit afterward. But I work slower after chec

I'd say it's much worse than that. If I stop to walk in a marathon, I can probably expect to run faster for a little bit afterward. But I work slower after checking email. It's more like drinking a beer during a marathon. (Taking a short walk outside during mentally difficult work does help.)