Shrapnel from two pressure cooker bombs that exploded killed three people and injured hundreds more.

For those who lost their legs, runner Bert Jacoby promised himself he would run the Boston Marathon.

"Blowing up people, murdering people in the name of something you believe in is just not necessary, it's not intelligent, and it's not productive," says Jacoby.

Harry Landers, the captain of the central Virginia team, has logged more than 600 miles in the past four months. He gets up and trains with the Boston team at the crack of dawn every week.

"We're always keeping our eye on the prize," says Landers.

Because there's so much bonding during training for the Boston Marathon, the captain calls his team a lifestyle group.

"You spend a lot of time together in the snow and in the cold, and we tell a lot of stories when we run and if we didn't already know each other, we're going to know each other very well by the time we're done so it's a tightknit group," says Landers.

Runners competing in the big race Monday say people killed in the bombings will be on their minds as they focus on the finish line. They are not afraid to return to Boston after the bombings in 2013. They say it's a chance to prove terrorism will not hold us back.

"By going out and showing them that we're not afraid of a backpack bomb, we're fighting against them in that way,” says Jacoby.

Most team members are either in Boston or traveling there this weekend. The central Virginia team plans to rest their legs before running the 26.2 miles on Monday.