ABERDEEN PROVING GROUND, Md. -- Heart pumping, pulse racing, and feet pounding the pavement, runners sprint toward a distant point in the horizon only visible to themselves. Runners brave the scorching heat and freezing cold, with dripping sweat or a white plume of breath the only indication of the amount of energy being put forth.

But, why do they do it? Why do runners run? Some say they do it for the long-lasting health benefits; others do it so they can continue to indulge in their favorite desserts; while others do it simply to be at one with nature.

Still, some runners run for a sense of camaraderie and esprit de corps they experience when running with a group of other runners. Right here at the U.S. Army Test and Evaluation Command, there are several groups of dedicated runners, and each year they participate in the third largest 10-mile running event in the world--the Army Ten-Miler.

This year marked the 28th running of the Army Ten-Miler that started in 1985 and is held each year in October in Washington, D.C. Lorrie Chieffo, an Acquisition, Readiness and Development branch chief, and ATEC's Ten-Miler team captain and team coordinator, ran her first Ten-Miler in 2006 and swore she would never do it again because of the sheer number of runners (the maximum number of runners for the Ten-Miler is 30,000).

"I ran it in 2006 and it was a really bad race for me," said Chieffo. "It wasn't one of my best ten-milers. It was too many people. I spent 10 miles just weaving in and out of people so it was just a negative for me all around."

Over the years she had a change of heart because so many people have asked her to set up another ATEC team. When Chieffo sent out a recruitment email in March, she said that the response she received was overwhelming.

"I initially had doubts, but I thought I would give it another shot and if it didn't work out then I wouldn't do it again if I had the same type of experience," said Chieffo. "But it was much better this time around. It was much more organized and it's a much bigger race. Plus, I was better prepared."

ATEC had six teams, A1 through A6, for a total of 47 runners (eight runners max per team) who participated in this year's Ten-Miler. The teams were comprised of a mix of civilian, active duty military, contractors, family members and friends. Starting back in August, the teams met twice weekly for group runs and their last group run was Oct. 18; three days prior to the race which was held Oct. 21.

Chieffo comes from a family of runners, many of them who've run marathons together. For some runners on her team, this will be the first major running event in which they have participated. Brian Simmons, executive technical director and deputy to the commander, has been a runner since high school, but only for exercise and the fun of it. This was his first time in a competitive running event. Nearing retirement, he felt that the ATM would be an opportunity to participate in something he hadn't done before and also to be a part of a long-standing Army tradition.

"It's yet another motivational Army event I have the opportunity to do to celebrate the Army's camaraderie. It's much farther than I've ever run before, so this has been a personal challenge," said Simmons. An added bonus is that he will be running the ATM with his daughter, Stephanie. "While she will finish well before me, this will be a great event together."

For Christen Sinclair, a contracted technical writer for the U.S. Army Aberdeen Test Center, this will also be the first race in which she has participated. For her, running is simply a way to get fit and, with a toddler at home, something she could do indoors or out. She signed up for the ATM because she was ready for a challenge. "I used to think if I could run 10 miles I could do anything," said Sinclair.

Libby Richardson, senior test officer and team lead for the Soldier Systems Division at ATC, started running five years ago when she tried out for her first triathlon. These days, Richardson's passion for running has become a very personal one. She runs in honor of and in memory of her son, Cody, who was killed in a tragic car accident in July 2011, only one short month after his high school graduation. In remembrance of Cody's life, who like his mother was also an amazing runner, Richardson formed the Cody G. Richardson Memorial Scholarship Fund and organized the first CGR Relentless Run. The first Relentless Run was held in June this year in Cody's hometown of Perryville, Md.

"Through it all, I've kept running; for Cody and for his legacy. It is the reason I still run today and for the ATM. He'll help carry me through," she said.

For other runners, running is a regular part of their Army lifestyle. According to Ken Jackman, general engineer with the U.S. Army Evaluation Center and an Army National Guard Soldier, running a competitive race is just one of the ways he motivates himself to run throughout the year. The same holds true for Capt. Brian Knutson, executive officer for AEC, who ran the ATM for the third time. Knutson ran track and cross country in high school, but he says that running and his cardiovascular health are a huge part of his Army physical fitness program.

"Although running is exercise and can be quite a workout depending on the course and distance, I find it to be relaxing and helps calm me mentally in ways that I can't get through other exercise," said Knutson.

Regardless of the various reasons that make runners run, Chieffo believes that the Army Ten-Miler provides an opportunity for runners to come together and represent their organizations in a spirit of competition and camaraderie.

"I think runners run for a variety of reasons that are usually personal," said Chieffo. "Some have weight loss goals, are trying to manage cholesterol or blood pressure, enjoy the peace that the great outdoors affords them, et cetera.

"Me personally? I run to escape my day to day life for an hour, and so I can fit in my clothes."

Her goal for this ATM was simply to have a great time and to lend support to the other runners on her team.

"There is a small amount of dread because despite all the training and preparation, you never really know how the race is going to go for you until you start running it," said Chieffo. "You could have done everything right leading up to the race and just have a bad day."

Command Sgt. Maj. Allen Fritzsching, ATEC's command sergeant major, who along with Chieffo helped form teams for the ATM, ran in this year's event, as well as assisted in conducting training runs and getting information out to ATEC employees.

"I was very excited for the opportunity to participate in this run with so many of our ATEC teammates," said Fritzsching. "I really enjoy the atmosphere and all of the people that are there. It's exciting."

Chieffo has already decided that she and her teammates will be running in next year's ATM.

"The ATM is such a great event. It isn't often that a race leaves you feeling proud to be an American and proud to support our Soldiers," said Chieffo. "Who wouldn't want to do it again?"