Johnylee
There are several things to raise with the Decision Maker, obviously, the distance that you actually walked but also that this occasion is in isolation, I assume that you do not go shopping and as a one-off, it should not be considered, lastly, that the assessor has not considered any pain, breathlessness or follow on effects that you might suffer from.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
