COPENHAGEN — The squats and leg lifts were harder than they looked, and after a few sets, Alfonso Aguirre Rodriguez placed his hands on his knees and attempted to compose himself.

In November, Aguirre, a 24-year-old professional video game player from Spain, joined the five-man roster of Origen, a League of Legends team that competes in the game’s top European league. The players — all signed in late fall — were told at the time that the team might be run a bit differently from what they were accustomed to. Now here they were, five young men who make their living sitting almost completely still in front of desktop computers, sweating through an hourlong workout in a cramped gym.

“I think I’m going to puke my oatmeal,” said Aguirre, who is known in the gaming community as Mithy. “I’m dying.”

Some years ago, traditional sports leagues were revolutionized by young analysts wielding computers. The way things had always been done, it turned out, was not always the best way to do things. Now echoes of that transformation have arrived in the growing world of professional e-sports, where gamers are being shepherded toward a new frontier, oddly, by the old, corporeal wisdom of traditional sports.