July 2 : As Norway prepare to face Brazil in the last 16 of the World Cup this Sunday - an opponent they have never lost to - managing player fatigue has become a central focus.
Star striker Erling Haaland scored Norway's 86th-minute winner in the 2-1 win against Ivory Coast on Tuesday, but said afterward that he was "dead tired" and could not have faced extra time.
Both Haaland and captain Martin Odegaard, who like many players have long and intense domestic seasons behind, them had been rested for Norway's final group match against France earlier, which ended in a 4-1 defeat.
But head coach Stale Solbakken said Haaland was "on his last legs" early in the second half, giving Norway supporters cause for concern ahead of their clash with Brazil.
"Can you undo the chronic stress that has accumulated over the course of the tournament, or the last season or two? No," said Dom Rae, a graduate in sports and exercise medicine who is working with Al Nasr in the UAE Pro League.
"These guys, especially the key players, have played a lot of matches," Rae said. "They are chronically fatigued. You're not going to undo that in five days. But you can certainly freshen up to a significant level by kick-off."
Brazil and Norway have at least faced similar challenges from their travel schedule and the climate in the host cities. Brazil have a six-day turnaround before their next match, and Norway five.
"What we generally see in sports performance is that the peak fatigue marker is around 48 hours," Rae said. "For some, it can trickle into 72 hours. But by 96 hours, into day five, everyone is pretty much back to normal.
"I'd actually rather have Norway's turnaround here than Brazil's," he said.
"When you only have three or four days, it's simple: rest, recover, prepare, play. But when you have five or six days, it gets tricky. You can't train too hard because you're too close to the game, but it's too long to do nothing."
After their group match against Iraq, Norway let their squad sightsee and travel around New York during their days off.
Rae said that has its benefits.
"Walking around New York is tiring, but the brain controls stress, hormones, and sleep. If you are psychologically happy, that emotional lift is just as important as pure physical rest. It was a calculated, necessary trade-off by the coach."
He has no time for those who grumble about the hydration breaks taking place in each half, even where the temperature hardly requires it.
"Players are losing fluids, electrolytes, and sugars, and glycogen utilisation is going up because temperatures are higher and the games are getting harder," Rae said.
"The teams that look at hydration breaks and say 'They're not going anywhere, so we need to use them as a performance answer' put themselves in a better position."