The phrase goes hand-in-hand with the philosophy of, "If it's a cold day and you are warm to start, you are probably overdressed."
I just checked the Weather Channel App, and for Sunday's Philadelphia Marathon and Half Marathon, the high temperature is only supposed to reach 48 degrees. It will be partly cloudy, with 10-15 mile per hour winds.
In short, conditions will be near-prefect for the 28,000 runners who will run on the streets where it all began.
They will run past Independence Hall, where the Declaration of Independence and the United States Constitution were debated an signed. And they'll run in the shadow of the Liberty Bell.
Runners will run through portions of Fairmount Park, 9,200 acres of one of the largest park systems in the nation.
They will follow the course of two rivers: the Delaware and the Schuylkill, between which the city is cradled.
28,000 runners will run in the footsteps of Pope Francis, who awed huge crowds as he rode down the Ben Franklin Parkway just weeks ago. Runners will start and finish the race there.
Along the Ben Franklin Parkway, runners will pass the flags of most of the nations of the world. In this time of deep division, both in our nation and around the world, the flags of nations should be an inspiration and a reminder of our global status.
With a mile to go, weary runners may summon up the grit and courage displayed by Rocky Balboa, immortalized by Sylvester Stallone in the 1976 film, "Rocky." Rounding the Philadelphia Museum of Art, the Rocky statue, gloves raised, located at the top of the museum's steps, will inspire magnificent finishes.
At the finish line, the mayor of the City of Philadelphia, Michael Nutter will high-five runners as they complete their journey.
It is a magnificent race, in a magnificent city, filled with gritty, hard-working folks who appreciate the efforts of extraordinary of folks who run long distances.
It might be a bad day to watch, but I guarantee you, it's going to be a great day to run.
Best of luck to all!