Just finished the last W4 run. It has taken me 10 days to complete the 3 runs for W4, not becase I found them terribly difficult, but because other things have got in the way. Today was my first run in 4 days. Out of all the W4 runs, this one I found very hard, and had to stop for 10 secs for each of the 5 min runs. Am now feeling very apprehensive about W5....... Also only managed 3km.