Olympic Cross-Country Skiers Eat 8,000 Calories a Day. It’s Exhausting.

PYEONGCHANG, South Korea — For the cross-country skier Martin Moeller, the biggest challenge of his sport is not the freezing cold, the intense training or the grueling toll of competition. It’s eating. And eating. And eating again.

“I actually do get tired of eating,” said Moeller, who lives in Greenland and skis for Denmark at the Olympics. “I always have to be thinking about what I will eat in two hours.”

Few sports ask as much of the human body as cross-country skiing, which engages virtually every muscle group — legs, arms, abdominals, back — for hours at a time. One of the enduring images of the long-distance cross-country events is the sight of athletes collapsing at the finish line.

That scene will no doubt repeat itself on this final weekend of the Pyeongchang Olympics as the men and women compete in their respective long-distance events — 50 kilometers for the men and 30 for the women.