Boost productivity with breaks, it sounds counterintuitive. After all, productivity means that you are doing effective work. And no effective work happens on a break. In fact, this is a limited view on productivity.
In the past, more hours of work had a direct effect on production. More man-hours, meant more manufactured goods. The relation between time and the items produced was obvious.
Yet even then people had the right idea about productivity. Allegedly, Ford shocked the world by adopting the 40-hour workweek. And it worked! Even thought it made no sense at the time, it boosted productivity.