I am slowly starting to increase my distances in preparation for a 14K race in August - still 3 months away. Today I did 8Ks - run/walk 2min/1.5min averaging 7&1/2 minutes per K. I run the 5K in 7 minutes or just a little less- but that pace would just be too much for me over the longer distance. I am aiming to be able to maintain approx 8 minutes per Klm for the duration of this training (up to 15KLm) - this way I would be able to sneak in under 2 hours for the race. So at the moment I have about a half a minute per K up my sleeve if the longer distance starts to slow me down. Not that there is anything special about that figure -- just to be able to finish it is good enough, but I think I would be able to walk it in around 2 &1/2 hours, so 2 hours for running would satisfy me.
I didn't have any problems finishing this distance this morning although it is the longest distance that I have transported myself over land on foot in my lifetime!! -- but I must admit that I am feeling a little weary right now -- may have to have a little lie down later!!