As fully-outfitted Chelsea firefighter Chase Armstrong ran up stadium bleachers, carrying about 75 pounds worth of equipment, his co-workers yelled out words of encouragement.

“Good speed, Chase, good speed! Good moving, Chase!” they shouted.

Armstrong and the other firefighters on the A shift at the Chelsea Fire Department spent time at Chelsea High School on Thursday, doing physical trials that simulated the actions firefighters must take when working at the scene of a fire.

Firefighter Cody Cothron said such physical trials are important to keep the firefighters in shape and ready for action.

“Heart attacks are the number one killer of firefighters,” Cothron said. “Part of that is due to being overweight, and part to stress. Any time you can get any group of guys together, it’s fun, and it’s a good way to work out.”

The different shifts at the fire department competed in a weight-loss competition from May 15-July 15. Now, the shifts are competing to see which shift can boast the best time in the physical trials.

The fire department is considering competing in the Scott Firefighter Combat Challenge, a national competition pitting municipal fire departments against each other in the same physical trials.

“We’re very interested in doing it, but it’s a lot of money and it takes a long time to prepare for it,” Cothron said. “If we are fortunate to get the money and compete nationally, we want to make sure we can compete.”

He said competing is less about the glory and more about being in shape.

“There’s a method behind the madness,” he said. “If you compete and you’re a firefighter, you’re in shape, you can stay in a house fire longer. You can go in and search one more room,” he said. “If you’re not huffing and puffing, you can make your air last longer.”

At the end of Armstrong’s run, he dropped the 165-pound dummy he was carrying and bent over to catch his breath as the timekeeper called out, “Two minutes and 13 seconds!”

The previous best time, held by a firefighter from another shift, was three minutes and 13 seconds. As the other firefighters burst into cheers, Armstrong just smiled, sweat running down his face.

“That was a good run,” Cothron said. “That was a real good run.”