Posted: 28/10/2014 at 21:51
The problem with all these long distance runs is, if you're a 'slower' runner, they take a long time. 15 miles at 9:30/mi is getting on for two and a half hours. The 20milers over three hours which can't be doing you any good at all.
I'm convinced running for time is going to be much better. Long run two and a half hours, maybe 16miles, then some 10miles midweek, nothing shorter than 7miles. So even if you're doing intervals or speedwork, pad your session out to 7miles with easy warm up and cool down miles.