After finishing third in the 35-kilometer race in Eugene, Karlström is relieved, happy, emotional, tired.

- I feel terrible....good, then, he says.

- The feelings come and go.

When I got here so.. I knew I was in damn good shape.

I knew I could fight for medals in both races.

I don't know what kind of tears it is.

It's double medal tears, he continues.

"Payed my mother back"

Behind the medals is a long and sometimes difficult journey, he says.

A journey made possible by mother and trainer Siv Karlström.

- She supports me in all situations and always has.

- Even when... It's like a job behind it, which is so incredibly many years... When I had zero kroner in the account, seven, eight years ago... which I have since paid back to my mother when I won prize money at competitions.

Today, the situation is more stable, but the mother still plays a big role.

- I've been back on the plus side for a few years now.

But she still means an incredible amount.

She never says no to accompanying me to a training session.

I'm still out camping all the time, I always have a room at my mom's house when I get home.

Wants to win four WC medals

With three medals from the WC, Perseus Karlström, together with Kajsa Bergqvist and Carolina Klüft, is one of Sweden's greatest track and field athletes.

But with his mother's support behind him, the goal is to become the biggest.

- Does anyone have four?

If there is no one who has four, then there will soon be a new championship, he says.