I came to the conclusion a few years ago that what we should be striving for is not to be productive but to be effective. We can be highly productive doing things all day, but did we really achieve anything? But this is even harder to assess than productivity. And then you have to take into account that some things you do are, in themselves, neither productive nor effective but may lead to increases in both - nurse training, in your example, or even something as simple as tidying your desk (something I admit is far overdue for me).