This is how the US military finds its ultimate tactical athletes

The Marine Corps is most famous for stripping away one's individuality at boot camp and spitting recruits out 13 weeks later as Marines, formed into bands of brothers (and sisters).

But those bonds were tested when some of its strongest, toughest competitors battled one other in the second-annual High-Intensity Tactical Training Tactical Athlete Championship. When the dust settled after the fourth day of competition, the top male and female Marines were crowned "Ultimate Tactical Athlete."

Sgt. Calie Jacobsen chewed up the final obstacle course event and took the top prize among 13 women who competed along 19 men to vie for bragging rights in the Aug. 15-18 service-wide competition at Miramar Marine Corps Air Station in San Diego, California.

Jacobsen, 23, a nondestructive inspection technician at Miramar, spent eight weeks preparing for the championship and held the lead going into the final event, the obstacle course. The other women wouldn't make that easy, but it was her strongest event. "I wasn't planning on winning. I just wanted to go out there and do good," she said. "The females definitely were at a higher level than I was expecting to see."

Jacobsen and the male winner, Cpl. Ethan Mawhinney, each received a championship belt and 53-pound kettle bell.

Mawhinney, a 22-year-old from Pittsburgh, Pennsylvania, beat 18 other male Marines in his second shot at the service championship. He placed sixth last year in the inaugural contest. "I trained a lot harder for the prelims this year," said the Marine air-ground task force planner from Camp Allen, Virginia. Winning "was surreal. I had left last year really hoping to take the title."

HITT is like CrossFit, but for and by Marines. That means using brute strength, endurance and determination to survive tactical battles against fellow Marines on the athletic field, in the water and on the paintball battlefield.

"Competition was tough," said Lance Cpl. Isaac Namowicz, an admin clerk with Marine Security Guard headquarters and this year's Quantico Marine Corps Base, Virginia, HITT champ. "There's a lot of passion."

Marines traded tips and even encouraged each other during the championship, but each had a mission: Win. "You're a brother, but at the same time, you are trying to beat everyone," Mawhinney admitted. That included the male 2015 Ultimate Tactical Athlete, Cpl. Joshua Boozer.

Boozer, ammo tech with 1st Tank Battalion at the Marine Corps Air-Ground Combat Center in Twentynine Palms, Calif., was champ this year at his home base but met his match at Miramar.

"It's not easy competition," he said, catching his breath after enduring the "500 Yard Power Shuffle" where competitors did nearly a dozen events including tire flips, box jumps, dummy carry, weighted sled pull and push and a variety of weight lifts — on a sweltering athletic field. It was the longest event, time-wise.

The Marine Corps organized its first HITT competition last year, held at Twentynine Palms. Like last year, Marines learned events' details at the start of the competition, so they didn't really know what they'd face.

Ryan Massimo, the Corps' HITT program manager and event coordinator, said the intent is to include some base-specific events – this year's "Maneuver Under Fire" took place at Miramar's paintball park – with physical challenges that reflect the strength and conditioning program. Last year, the run up and down the desert base's hills while lugging heavy items made "sugar cookies" of a weakened competitor.

This year's championship included a timed water event, the "Amphibious Tactical Challenge." Competitors in boots and utes swam multiple laps bearing their pack and rubber rifle, and then they traversed the pool, diving and ducking with a pack under markers before cranking out 10 (men) or 5 (women) pushups wearing the pack. "It did definitely throw a curve ball for some people," Mawhinney said.

Namowicz said he struggled in the pool.

"I was not expecting all that weight. It felt like cinder blocks," he said. "My upper body was getting tired."

At times, he'd talk to himself as he pushed weighted sleds or carried 35-pound ammo cans and 120-pound dummies in the sweltering heat. "I just kept saying, 'Finish this.' You have people in the stands pushing you, and it just keeps you motivated," he said. "You just want to be done."

Jacobsen hadn't real plans to become competitive until the Miramar HITT Center coordinator encouraged her to the local HITT combine challenge. "I didn't know how big it was, that it was Marine Corps-wide," said the Nebraska native. "We just went in unassuming."

And she finished first among the women, getting the ticket to compete against other installation winners for the championship.

She's a HITT convert. The isolation workout she previously did for weightlifting "isn't applicable to everyday life," she said. Interval training demands endurance and strength and "is a lot more applicable to everyday life. That's definitely changed my mindset."

Thin crowds watched this year's competition, but Jacobsen said she was glad to see her station commander and sergeant major on the sidelines. "It's an awesome event, and it needs to be more widely broadcast," she said.

It's certainly not as well-known as the military's most famous tactical-physical competition, the "Best Ranger."

The 60-hour event at Fort Benning, Georgia, pits Army Rangers against each other in two-man teams to test their skills, including land navigation, small-arms firing, obstacles and, in true Ranger style, parachuting.

Not to be outdone, Marines run the less-known but still grueling and gung-ho "Recon Challenge" at Camp Pendleton, California. After a predawn swim in the Pacific, two-man Marine Recon and Marine Raider (and Navy recon corpsmen) teams run in boots-and-utes with rucksack and weapon, enduring a nonstop series of grueling events in the pool, on the range and along Pendleton's roller-coaster scrubby hills.

A close parallel to the HITT championship may be the Army's "Best Warrior" competition, a four-day contest where soldiers complete tactical challenges, written exams and fitness events in more battlefield-like environments. The top 10 soldiers and 10 noncommissioned officers who've bested their local competitors will vie for the title at this year's contest, to be held Sept. 26-Oct. 3 at Fort A.P. Hill, Virgina. The Army National Guard held its own contest on June 22 at Joint Base Cape Cod, Massachusetts. Events included a 14-mile ruck march.

The Air Force's 1st Air Support Operations Group put airmen through grueling individual challenges and 22 events over a week in July for "Cascade Challenge 2016."

The contest, held at Eielson Air Force Base in Alaska this year included navigating the wild Alaskan forests with body armor and 50-pound rucksack.

The Navy takes a different tack in sailor competition. Its surface fleet of destroyer, cruiser and frigate crews each year showcase their athletic and professional naval skills during "Surface Line Week." Sailors went toe-to-toe in firefighting drills, valve packing, welding, small-arms shooting, sailing and stretcher-bearer races. Team events include dodgeball and soccer, so fun is the operative word.

East Coast units this year even raced off in a cardboard boat regatta.