When Sarah Sjostrom broke the 100m butterfly world record at the 2009 World Championships in Rome aged 15, little did she know it would be six years before she set another personal best in that event.
The Swede won European gold in 2010 and looked on as her world record was broken at the 2012 Olympics.
She was crowned 2013 world champion in Barcelona but 2015 was the year she broke through her own barrier, first of all at the Sette Colli in June where she became the second fastest woman in history over 100m butterfly.
Then at the start of August at the World Championships in Kazan the 22-year-old twice brought down Dana Vollmer’s world record, first in the semis and then to 55.64 in the final.
It was the first of two gold medals in Russia – and five overall – but it also meant she had again set a new personal best but this time under intense pressure in the midst of a heavy programme.
“I have been waiting six years to break my personal best time. I did it at the Sette Colli and now I have taken a few more tenths of a second so finally,” she smiled.
“Of course this record was meant to be broken. It was my plan all along – to beat a record at these Championships; I’ve been gearing up for this.
“I know there is more pressure coming into the final. There are always more feelings before the race about the final so I am very happy and I have shown myself I can swim faster even with all the pressure.”
Sarah, who trains under Carl Jenner in Stockholm, was a European champion at 14, a year before her gold-medalling swim in Rome.
However, the last 12 months have been stellar for Sarah with seven medals, including three golds, at the 2014 European Championships weeks after she had set a startling world record of 24.43 in the 50m fly.
There were also three golds and a silver at the World Short-Course Championships in Doha last December.
What is the secret behind such consistent success?
“Now I have more competition in training, I race the boys,” she explains.
“I think I can do my tapering much better – before my body was changing a bit when I was a teenager, it was not that easy.
“I didn’t know really what to do with the taper, now it works better so that is why I can swim faster when I come to the international competitions.
“Last year my focus was to get the speed faster so that is why I think my times were so fast last year and now focus is more on the 100 fly.
“So now I can bring the speed from the 50 to the 100 so I feel I have the endurance to swim on the last 50.”