Run Don't Walk

Now that I am able to walk/run 5 miles, I need to run-walk the distance i.e more run than walk. I can hike more than that distance, so why do I feel so tired when I try to walk-run? I wonder if it is a mental thing. I have hiked with heavy climbing involved just recently and am sure I can do 10-12 miles of such hiking even today. Why can't I jog half the distance slowly? It must be a mental thing. I am mentally challenged when it comes to running.

Today is the day for my personal run.