Editor's Note: This article originally appeared on Business Insider.

Members of the U.S. Special Operations Joint Task Force stationed in Kuwait conducted a training session dubbed “Chuck Heavy” in honor of a U.S. Navy SEAL who was killed four years ago this week during a firefight with ISIS fighters in Iraq.

U.S. Navy Chief Petty Officer Charles Keating IV, 31, was a member of a quick-reaction force responding to a request for assistance from US advisers who were assisting local Kurdish peshmerga forces in Tel Askuf, about 20 miles north of what was an ISIS-held city of Mosul.

After around 120 ISIS fighters and 20 armored vehicles assaulted the town, a group of Navy SEALs were called in to repel the advance. The ensuing battle was so fierce that aerial support was also dispatched — A-10s, F-15s, F-16s, B-52s, and drones were all scrambled to assist the ground forces.

Keating, who was on the rooftop of a building picking off the militants, was fatally shot by small-arms fire.

“This was a large fight, there's [no] question about it,” Col. Steve Warren, a Defense Department spokesman, said at the time.

Keating was the leading petty officer of the SEAL's sniper and reconnaissance training cell in the West Coast of the US, according a military press report.

“Everybody loved Chuck,” Lt. Cmdr. Jeff Gardner, an executive officer for the Special Operations Joint Task Force, said. “There's not a person that didn't love him, and he always had this huge smile on his face. He was just a fun guy that everyone wanted to be around.”

In honor of Keating, the special operations community in 2016 created a new “workout of the day” (WOD), a training session consisting of “functional exercises for the type of role they undertake.”

At the completion of the exercise in Kuwait, service members shared non-alcoholic “near” beer, the only authorized drink resembling the alcoholic beverage in the country, from an emptied ammunition can.

Here's what the “Chuck Heavy” consists of:

  1. 1-mile run
  2. 100 push-ups
  3. 1-mile run
  4. 100 thrusters using equipment or air squats
  5. 1-mile run

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