Kicker wrote:
... The key for the second run was to get to it without all the "Jeez, I can't run because there's no shower."
The runners who thought that way were people I generally beat in races because they couldn't run the mileage I did because there was no shower available.
Kicker -- I see you are not a fan of lame excuses ;-)
So here's my doubles experience. I am 51 & female. A couple of years ago my husband thought I should try doubles in my marathon training, and run ~70 mpw. So I basically tried to run 5 miles every 12 hours. For some reason 70 mpw wears me out WAY more than 60. Every now and then I'd skip a run and then do a longer one on the weekend, or do a 4 & 6 instead of 5/5. Well, I was tired all the time, and felt like I never quite recovered from the previous run and #$%@! it'd be time to run again. I didn't have the energy for much speed work, and only did 2 long runs which were kind of disastrous. So I went to this marathon all crabby and thought I didn't do enough speed work, I didn't do the necessary long runs, and I was going to prove to my husband that his recommended training methods would not work for me. I'd run about 40 marathons before, but I PR'd in this one by 7 minutes, at the ripe old age of 49, and beat my Boston qualifying time by 47 minutes.
Soooo, as much as I dislike them, and like many others who responded here, doubles worked for me, increasing mileage without getting injured.
With regards to family, my husband likes to run doubles, and our kids are old enough to not care if we're gone for an afternoon/evening run. I do lots of my p.m. runs from the house, or (gag) on the TM, to minimize the time away (when kids think I should be doing stuff like making dinner!) The hard part for me, aside from being kinda tired all the time, was that as soon as you finish one run, you're immediately planning the next one. Also the afternoon/evening run could potentially interfere with your social life, if you have non-running friends ...