Hi Dr Dan,
You are right my long run is too long now. But without writing a book... it didn't start like that. 6 months ago it was like 2,3,2,4 (4 runs per week). Gradually increasing so it was 3,4,3,5 (last long run being on a Sunday). So over the months I'd get up to something like 4,6,4,8... and I am real comfortable at this mileage... but around 20 to 22 miles... I can stay at... week after week. But it's not really enough for a half marathon. But once I move up to 4,7,4,9 (24 miles per week) my problems start... I don't ever seem to be recovered. Even though I am adding barely a mile to the weekly total to get there... so I ease back to 4,6,4,8... (22 miles per week) and all is fine again... but I know it isn't enough... ok... 4,7,4,8... (23 m/w) borderline... niggles start... back to 4,6,4,8... (22m/w) ok again... try again... but this time... drop a day... 4,6,9... (19m/w) I'm ok as my weekly mileage hasn't changed much.... then 4,7,9... (20m/w) still ok... 4,7,10... (21) borderline but ok... just... 4,7,11 (22m/w) starting to get uncomfortable again... so I drop another day... 7,11 and I feel ok... but I know it's only a matter of time...
I just can't work out a way to get past 20-22 miles a week... consistently... without getting injured/recovery fatigued.