Frida today is at the highest level we have ever seen from a woman in freestyle cross-country skiing. A higher technical level than either Therese Johaug or Marit Bjørgen have shown, he tells VG.
Earlier this week, Johaug said that she does not think Karlsson has developed since the Beijing Olympics four years ago.
"I think Frida is still very unstable," Johaug told VG.
After Karlsson's convincing Olympic gold on Saturday, it sounded different.
"There is no doubt that she has hit her stride and is in great shape. It is impressive to see how she handles the race from start to finish," says Johaug in NRK's studio.
