IMO 50% reduction is very different to 50% of the energy. The average person would be hating their life if you took away 50% of what they do (and replace those hours with lying in bed). That they could only work half the hours (so their income is halved) and spend only half the time going out, half the time with family, etc. However IMO you could take many average people and cut their energy in half, and they could still do most of what they normally do, because I think people usually have excess energy and don't use it. They could be out running 10 miles a day (once they worked up to it) but instead they sit at their computer or TV or in a restaurant. So half their energy, and now they can only do 2 miles a day without pushing themselves... they can easily still go out shopping, drive to see friends, work at a desk 40 hours a week. I have dreamt of having 50% of a healthy person's energy. That's confusing. I wonder if expected means the minimum a person could do and support themselves? The amount you would expect every person could do? That seems more like it. And it's 30-50% of expected so not keeping up.