just did not feel up to it

Sunday--planned to run what's become my usual 11.5 on Sunday, but just did not feel up to it. I was running at a good pace of 7:15 for the first few miles, then I dropped the pace to 7:00. I hit the 5.75 mile mark in 40:50, took a sip of gatorade as I passed my mailbox. I continued and then stopped at about 7 miles. I walked for a bit and then finished the last .5 mi.