[tweetmeme source=”elizabethev” only_single=false]This is why my legs feel like lead this morning. It’s also my excuse for falling up the stairs in my office building this morning. [youtube http://www.youtube.com/watch?v=52wRx7DkjS0&w=560&h=349] That last hill was no joke. The cheering crowds and breathtaking scenery, however, kept me smiling for the full 7 miles. And this is why my arms are going to feel like spaghetti tomorrow morning. And this is why I won’t…