CrossFit – the grueling fitness program that began as a way to train first responders and military – has workouts named after men and women who have died in the line of duty.
They're called "Hero WODs" (workouts of the day).
On Memorial Day, nearly every CrossFit gym in the world runs the same workout, the most famous Hero WOD: Murph.
Murph is named for Medal of Honor recipient, Navy SEAL Lt. Michael P. Murphy, 29, of Patchogue, N.Y., who was killed in Afghanistan June 28, 2005. You might know him from the book and movie, "Lone Survivor," written by Marcus Luttrell.
Here's the workout:
"Murph"
For time:1-mile run100 pull-ups200 push-ups300 squats1-mile run
It was Murphy's favorite workout, except he called it "Body Armor" because he'd wear a 20-pound vest when he did it.
In this video, you can see professional athletes "doing Murph."
But what's really amazing is when everyday people come together in their gym to do the workout, honoring a hero they might never have known about.
Many gyms register with The Murph Challenge, a fundraiser led by the Murphy family's foundation, The Lt. Michael P. Murphy Memorial Scholarship Fund, which awards 18 educational scholarships each year.
Related: CrossFit gyms honor veterans with Armistice workout.