KIRTLAND AIR FORCE BASE, New Mexico -- The 21st Explosive Ordnance Disposal (EOD) Company hosted the 3rd Annual Blackjack Challenge here in May.

Five Soldiers, two Airmen and seven civilians participated in the three-day challenge.

The 21st EOD Company is part of the 71st EOD Group, 20th CBRNE Command (Chemical, Biological, Radiological, Nuclear, Explosives).

Headquartered on Aberdeen Proving Ground, Maryland, the 20th CBRNE Command is home to 85 percent of the Active U.S. Army's CBRNE forces.

Sgt. 1st Class Joel L. Koekkoek, the coordinator of this year's challenge, said the most difficult part was the first day, which included the Army Ranger physical fitness test, an 8-mile foot march with a 35-pound pack and a 1050-meter swim carrying a brick.

The Army Ranger physical fitness test alone includes pushups, sit ups, curl ups and a five-mile run.

The participants took part in a weight lifting circuit on day two and the challenge culminated on day three with a seven-and-a-half mile run up the La Ruz Trail, which reaches 3,500-feet above sea level.

Koekkoek said the event was started by Capt. James Akins in 2012 as a fitness challenge for the different teams within the 21st EOD Company.

Since then, the challenge has evolved to include Airmen and civilians.

According to Koekkoek, being an Explosive Ordnance Disposal technician requires a high level of physical fitness.

"You are expected to be able to keep up with the Infantry while working dismounted, work for multiple hours in an 80-pound bomb suit and be able to pick up and carry loads in excess of 100 pounds over long distances," said Koekkoek. "All of this is required while keeping a clear head, thinking critically and communicating clearly."

Koekkoek said the Kirtland Air Force Base-based 21st EOD Company holds intense physical fitness training but none of those training sessions are as hard as the challenge.

"The challenge is much longer in duration than any typical PT session and requires almost inhuman amounts of endurance," said Koekkoek, a native of Springfield, Oregon, who deployed to Iraq twice.