Mondays are often described by many as the most boring day of the week.
For the Elfsborg swimmer, who trains at the National Elite Center (NEC) in Stockholm, it was a day of joy.
She cried with joy and relief when she broke her personal best by three hundredths of a second in the morning's heats and advanced to the semifinals.
In the evening, she was beaming with happiness after smashing the morning time by 56 hundredths and clocking 53.87.
Fourth Swedish
She was 25 hundredths of a second shy of a place in the final and finished 12th - but became the fourth Swedish female swimmer of all time to go under 54 seconds.
Only Sarah Sjöström (who lost the world record in June), Michelle Coleman and Therese Alshammar have done it before.
A simply great day for a swimmer who had despaired and had low self-confidence.
"If I had gone into the championship and felt that I was good, then I would have believed in this. But as I have felt lately, that I have been nervous and did not believe in myself, I did not believe in it," says Åstedt.
“Do a lot”
It will make a huge difference for the next two years (until the Olympics) to be able to "push" six tenths. Then maybe I can push the time down a little more in two years.
During the day, she also swam the final leg of the 4x200-meter freestyle - where Sweden was eliminated - in two minutes.
The 200-meter freestyle is her next event at the European Championships in Paris.
I've been focusing a little more on the 100 in the last two months, but I haven't lost 200 meters. I've been training it for three years at NEC - and it went well this morning. So it will probably go well, she says.
What do you think?