“The actual physical ability to do ski jump isn’t that hard,” Shapiro said. “Psychologically, getting yourself to do that is definitely the hardest part.”

Hanover Coach Tom Dodds explained that the correct form feels unnatural. He regularly tells his jumpers to quiet their chests. “If you squat down and jump, you’re going to rev up your whole upper body; that’s how you get your energy,” he said, but “jumping is bizarre.” He added: “You don’t want the upper body to move at all. It just stays completely placid and gets pushed along by the hips like a wet noodle.”

A good jump requires athletes to lean their bodies out over the tips of their skis, a move that is treated with gallows humor by many, including the Concord High School senior Julia Finch, one of the top two girls jumping this season.

“It’s totally against my instinct to lean forward to my death,” she said.

Some overcome jitters quicker than others. Freestyle skiers, like the newcomer Ian McCluskey, a junior from Hopkinton, throw themselves off the jump with abandon. As he flew past at one practice, black dreadlocks shaking from underneath his helmet, Concord Coach John Fulton said, “He’s got springs on him!”