Maja Dahlqvist had a great start to the Tour de Ski when she came second in yesterday's sprint.
Today was not as cheerful.
- It felt bad right through, she tells SVT Sport.
- I have never felt so bad, I think.
I can't seem to get any air.
It's just getting around.
Dahlqvist does not know what causes it.
- I don't know if it's the high altitude or something stuck in the back, she says.
- The rest day is becoming quite important for me now.
Frida Karlsson, who came third, had no major problems with the height, but believes that it can affect it.
- It's a little scary.
And I have lived low, unlike many others here during Christmas.
It's a bit scary and can go either way, she said after the race.