I don't really understand the problem here. This is a fairly binary problem, if you love your wife you will skip the race. Come on now, running is just a hobby of yours, your wife is your soulmate. During the exchange of vows you promised for better or worse and this just so happens to be one of the 'or worse' times. While I am sure you would like to run the race you shouldn't forsake your wife for the opportunity. Valentine's day should be treated as a sacred day by those that pledge their love to one another. Not spending the day with your betrothed would be like not eating turkey on thanksgiving, or not exchanging presents on Christmas, or not counting down for New Years, or not watching fireworks on July fourth, or not drinking beer on St Patrick's day, or not hunting for eggs on Easter, or not dressing up on Halloween, or not reading the Declaration of Independence on President's day, or not pretending to have a heart attack on April 1st, or not calling your parents on Mother's/Father's days. There are just certain things one MUST do to live a respectable life.
Just grow the f*ck up and realize that this world is not all about you.