Posted: 29/09/2014 at 09:08
You need to do long runs in one piece really, to develop the mental toughness to just keep going. Having said that, there's no need to be superstitious about it, and sometimes breaking it into chunks helps you get round if you really need to get the distance under your belt.
I'm still feeling a bit weak after a cold a fortnight ago, but I really needed a three hour run for confidence purposes. June was the last 30 km/3 hr. So I ran 7 km while waiting for the GF to get ready, picked her up at home and ran 5 km together. Dropped her at home and went out again, taking it easy up to 3 hrs/28 km total. At that point I was home and had a bit of a drink and half an energy bar. Then I thought I might as well run the extra 2 km to make it 30.
A long run is still a long run even if it has short mental or even actual breaks. So long as you keep the breaks short enough so that there is no real recovery it can help you complete the goal.