While runners competing in the 126th Boston Marathon spend the days leading up to the race getting in last-minute training, volunteers put on bright yellow jackets and set their alarms for hours before the start of the race. The marathon, known for its world-class athletes, would not be possible without the work behind the scenes.

Some of these volunteers are first-timers, looking to take part in the event that means so much to the city’s heritage. Others are former residents of Boston who return each year to connect with old friends while they pass out bibs and direct runners for the duration of race day. 

Madeleine Keefe, a junior at Endicott College in Beverly, attended the race with her father. The 126th Boston Marathon was her first experience volunteering.

“[The marathon] is such a big part of Boston culture and it’s so important to the city,” Keefe said. 

In the week leading up to the race, she helped with hospitality, working to welcome the elite athletes traveling from all over the world to Boston. On the day of the race, she and her father were tasked with checking in the other volunteers: they arrived at the Copley Square area at 6 a.m. and were finished around noon. 

“Even though it’s so early in the morning, everyone was in a great mood, the energy was really alive,” Keefe said.

Many of the volunteers return each year for this feeling: the exhilaration of watching runners cross the finish line and the camaraderie of working alongside friends and family to make sure the race goes smoothly. 

Peter Leclerc, a resident of Holyoke, has been volunteering at the marathon for five years. This year, he worked in the runner recovery area, located just to the side of the Boylston Street finish line. He said he loves watching the end of the race.

“Being at the finish line is probably the coolest experience that anyone involved in this race can have,” Leclerc said. “It makes me think of the attack all those years ago, but it’s also great to see how alive it is. When people cross the finish line, you think about how often it was their life’s goal to do that.” 

For volunteers and Boston residents alike, the celebration of the marathon comes with the memory of the 2013 bombing. Thomas West of Wakefield said many of the volunteers, himself included, are celebrating their seventh year of volunteering, having joined the efforts the year after the attack. 

“The bombing was my freshman year at Northeastern,” West said. “My friends and I watched the attack from the TV in [the Stetson East residence hall] and we didn’t like seeing our city attacked. … A lot of us volunteered after the bombing and now it’s a great tradition for us.” 

West said the annual event allows him and his former classmates to stay close, though many of them have graduated and moved to other parts of the country. His volunteering team is often the same each year. 

“There’s some people that I only see here once a year,” he said. “I get to hear about what’s going on in their lives, like [a fellow volunteer] got married and bought a house since I last saw him.” 

West volunteered at the main entrance for the grandstands and supervised the family reunion area Monday, helping runners find their loved ones after finishing their race.

“30,000 runners can’t all meet at the same place,” West said. “It’s important to keep organized.”

For veteran volunteers, part of the experience is seeing the race change over the years. Setup changes and new technologies have modernized the way that check-in and timing are conducted. Jeff Newton, a resident of Brookline, began volunteering 30 years ago with a colleague who was responsible for the marathon’s finishing system.

“I started out doing chips and medals, and that was great, but then they got rid of the chips,” Newton said. “I’ve been through most of the system and its changes. I did blankets, I did Gatorade, I’ve really done it all.” 

Newton has been through decades of races — and the various conditions that come with them.

“There’s a lot of memories for me here,” he said. “There was one year where it was really hot and people were dropping all around us. There’s years in the rain and in the snow, and we’re here for it all.”

He said he recommends Boston residents get involved in the race in order to better experience the city.

“The marathon itself is a crazy distance and accomplishment,” Newton said. “I encourage people to participate in any way they can, even if it’s just cheering people on. Being a part of the system is great.”