I had a nasty cold / sore knee combination that took me out of action for about two weeks. It's crazy how much you can regress by taking two weeks off from running.
I was up to running 8 miles before I stopped and I've just gotten 4 2 mile runs in this week as I try to build back up again. Part of it is definitely my fault as I am trying to run on a very significant caloric deficit and it's pretty easy to bonk by the end of the runs.
I was running on a caloric deficit and once you start hitting 6+ miles I find it gets pretty tough. Just so much less energy, and more risk of injuring yourself or passing out. It's sort of hit and miss too, some days will be ok and others will be torture.
I started having about 200-400 calories, something like a piece of bread or a granola bar or something, with a good about of carbs, about an hour to an hour and half before my runs and I end up being able to do miles and miles without even being out of breath. So much easier!
I'm getting pretty nervous about my half next month... I have yet to run more than 9 miles, and this one is 13 miles! Though, honestly if I allow myself to take 5 minute walking breaks I think I'll be fine. It's still too cold and snowy to run outside so I've been doing the treadmill at the gym...
I run 7 miles on the "hill challenge mode) which alternates 1 minute of flat and 1 minute of incline, with the incline increasing from 1.5-3.5 and then repeats. After, I'll run a few miles on flat after a 5 minute walking break. Unfortunately, I have no choice as the treadmills at the gym kick you off after 1 hour, so I need to let it do the 5 minute cooldown cycle before I can restart it again.
I figure the hills on the treadmill are bigger than any I will be running during the half, as it's a pretty flat course. And I certainly won't be running uphill for 1 minute intervals at any point, so I figure I'm preparing myself for the worst this way. I also find that running uphill is like running a longer distance flat... I use a few running trackers but the pedometer in my ipod adds on almost an extra 1.5 miles over an hour when I do a run with hills, compared to flat. My last run was about 13 km and my ipod estimated it was 16 km.