My first 5 mile run

I did my first 5 mile run in Central Park on Saturday. I had a lot of fun but I noticed a trend in myself that I am not sure is a good or bad thing. The park is very hilly which saps my strength, so I tend not to overexert myself with the intention of saving some for later. When I hit the last mile I knew I was going to finish and finish well under my goal time. I finished sprinting and felt I had more in me. A lot more. My friend, who doesn't run regularly, joined me in the race. Today he is sore, every muscle hurts. I feel fine. Should exercise exhausted me? Will I only progress to the next level if I feel some burn?

Next month I am doing a 4 mile run benefitting Central Park, my favorite place in the world. For my training I will focus on running up the hills. My goal for the entire 4 miles is not to walk.

I ran/walked the 5 miles yesterday in 1 hour 02-minutes and 40 seconds. That's a 12:32 pace. I know I can do better than that. But it was my first official run so I am happy with my performance.