My knees hurt.  Do you know why they hurt?  
I ran.  
I know I know, running is stupid and goes against everything I stand for.  I never intended to run when I went to the gym today.  I was just going to walk on the treadmill for a few miles.  I only really like the treadmill cause you can watch television when you walk.  Unfortunately for me I was in front of the TV with the Home Garden network on.  I think that's the only official way to get your heart rate to rise when you watch that network.  So I was walking minding my own business when a hefty lady got on the treadmill next to me.  I was walking at a brisk pace of 3.9, not a neurotic New York pace, but fast enough to lose an elderly man who was chasing you with a heavy axe.  I look over at the portly lady to glance out of curiosity at her pace and she is at 4.5!  Oh no you don't, I was not about to let her go faster than me.  So I upped my pace and before I knew it I was jogging.  I couldn't believe it, jogging, how disgusting, I felt so dirty, but she could not win!  All I know is that I ran 2 miles at a 5.5 pace and I beat her!  She quit first because she couldn't hang with me.  
I'm sure she had no idea of the drama that was going on next to her but I owe her a lot.  From now on when I go to the gym I will pick the treadmill next to her and those of like poundage to motivate my heart rate and help my self esteem.