Planned out a one-way 10K run/walk to an area that is slightly unfamiliar to me -- ending at a small shopping centre , where my wife could pick me up and we can have a coffee!!! I knew that the coffee shop was at the top of a bit of a hill-- but didn't appreciate that it was at the top of a 60 metre rise over 1.5 Ks - and I thought I was doing so well after the first 8.5K!!!
Lesson learned -- don't plan a run which finishes in a big hill!!!!