ARDMORE, Okla. (KXII) - It's called the Murph Challenge.
It starts with a one mile run, followed by 100 pull ups, 200 push ups, 300 squats and ending with another one mile run - all while wearing a weighted vest.
The challenge takes place on Memorial Day every year to remember Lt. Michael P. Murphy, a Navy Seal who was killed in the line of duty in 2005.
"This was his favorite workout and so every Memorial Day gyms from all over the United States get together and honor him and all the fallen heroes," Jeff Miller said.
Miller is the head trainer and one of the owners of The Fitness Professionals gym.
He says they started hosting the challenge three years ago.
"They're fighting for our freedom and that's why we are actually able to get together and unite and do this today because of what they've done," Miller said.
This year's participants included a group of local police officers.
"if it wasn't for some of those guys that did lay down their lives and paid the ultimate sacrifice, they wouldn't be able to come home and see us." Cpl. Matt Miller said.
Ardmore Police Corporal Matt Miller says it's his second year completing the challenge which he finished under an hour.
"The easiest thing you can possibly do is look at somebody else that is struggling and say come one man lets go, keep going, " Cpl. Miller said. "Because that in turn keeps you going, it makes you forget about the pain you are going through and try to help your fellow man out."
The money raised by those who register online on the challenge's website go towards the Lt. Michael P Murphy Memorial Scholarship Foundation.