Isaac Douglass says when he was in seventh grade his “training” regimen consisted of playing “Call of Duty” for hours while eating spoonfuls of goldfish crackers.

That kid probably wouldn’t recognize his current self.

Douglass, 18, now spends three-hour sessions running on a treadmill set at 8 mph. Or he’ll head out to his wooded backyard in North Berwick and practice climbing a thick rope while wearing a weighted vest with a sandbag yoked over his shoulders. Douglass meticulously crafts his diet, preparing his own meals from supplies kept in a personal fridge set in the dining room of the family home.

Isaac Douglass of North Berwick competes in Spartan Races and trains by distance running, climbing rope and carrying heavy objects around, like the 60-pound sandbag on his shoulder.

Isaac Douglass of North Berwick competes in Spartan Races and trains by distance running, climbing rope and carrying heavy objects around, like the 60-pound sandbag on his shoulder. Gregory Rec/Staff Photographer

Douglass competed in track and field for Noble High but the recent graduate really found his athletic niche a few years ago when he entered his first Spartan Race – a branded name for a civilian replica of a military style obstacle course.

“The Spartan Race is kind of a way for me to go off and show what I’ve been training for,” Douglass said. “For the Spartan Race it’s really all for me. It’s just a nice way to reward myself and I really love going on them.”

Racers routinely have to climb over walls, cargo nets and ropes that often include cold-water landing areas. Carrying heavy objects like sandbags, buckets of gravel and logs up and down hilly terrain is a given. There are spear tosses and fire pits. A failure to clear an obstacle “earns” the racer a 30-burpee penalty.

Oh, and of course, they crawl under barbed wire in a mud pit.

“There are plenty of barb-wire crawls,” Douglass said with a laugh. “And there’s plenty of rocks and gravel in the mud to dig up your elbows and knees, and make it nice and bloody.”

Last summer Douglass’ training and improved technique came together when he entered his first “Beast” race in Killington, Vermont, a long-distance event designed to test physical and mental limits.

“I went to Killington saying I would do the best that I could,” Douglass said.

He finished 17th among 365 competitors in the Elite Division that covered nearly 15 miles. It took him 4 hours, 15 minutes, 33 seconds to complete the course. Douglass won the 18-and-under division. Only one person under the age of 20 was faster in a race where seven people finished in less than four hours. The Killington winner went on to finish 30th overall at the Spartan World Championship in Lake Tahoe, California, three weeks later.

Douglass’s effort in Killington also qualified him to attend the World Championship.

“It would have been very expensive to get there and it was such short notice,” Douglass said.

Douglass is scheduled to make his first Spartan start in 2016 on July 29 in the Beast Elite race in Montreal. The race will be 12 to 14 miles long and include 30 to 35 obstacles. He plans to return to Killington for another Beast race and the big goal is to again qualify – and this time attend – the World Championship, set for Oct. 1-2, in Lake Tahoe, Nevada.