Many of us seem to place much store by of FEV - which in many respects may be mis-placed. FEV typically goes up and down, day-to-day depending on many factors. (My FEV was 17% in April 2012; 25% in September 2012 and currently stands at between 17-18%. My respiritory specialist (one of the leaders in this field) cited examples with one of a chap whose FEV was in the 500s and an oxygen saturation level of 99-100%, and he could not walk 50 metres. Another expample was of a chap whose FEV was around 14-17 and yet he continued to enjoy life including walking a half-marathon. He did not break any records - taking more than 7 hours - but he did it. These anecdotes give me some comfort as does Michael McBride in the US (Google him). Thus recorded FEV is just a figure and does not wholly determine what we can achieve.