Park roads, again

After Iron Works this evening, I went out to the park and ran 5 miles up and down on the park road hills.  This Saturday, I will be running the 10 for Texas in The Woodlands.  I ran this race in the late 80's before it was discontinued and brought back in 2006.  I ran the race on October 15, 1988 in 1:25:16 (my PR for 10 miles).  I was 47 then, but still wonder how I ran that fast.