Jan Castillo is one of those people who make you terribly envious at first glance. The first thing that comes to mind after meeting him is a question that is as obvious as it is inevitably tinged with jealousy: how can he maintain such an active sporting life while being a third-year medical student (who actually passes his courses)?

At 12, he started running some weekends along the trails of Collsuspina, and today he is a true elite athlete and a leading figure in mountain running. Or trail running, he says. It sounds better.

I ask him why I should run in the mountains. Every athlete will tell you that their sport is the best. Of course. He adds that the mountains make him feel very small, and that when he runs, he thinks of nothing but the here and now. He clarifies - probably to make me feel better - that everyone is good at something. I run.

He confesses that his dream is to combine his medical career with his sporting career. I look at him and can't quite believe it's possible, but then I remember that he is already doing it. At just 20 years old. And the envy returns, of course. But he doesn't depend on a salary or emotional stability. If one day I can no longer do it professionally, it will always be my hobby. I will never stop running. He finishes the sentence, and it seems to me like a very beautiful way of seeing the glass as half full. This stands out in Jan. Optimism is his trademark.

For some time now, I've been overwhelmed by the fact that everyone runs these days, and I take the opportunity to talk to him about it. What's going on that my friends now run 10-kilometer stretches on any quiet Sunday afternoon? Why do I keep seeing 'running clubs' everywhere? Are they here to stay, or are we still dealing with the hyperactivity aftereffects of a hazy lockdown that we've already forgotten? Jan is clear about it: this is here to stay. It's an inexpensive, addictive sport with flexible schedules that is easy to practice. It makes sense, of course. And running clubs are the same: people leave the house, socialize, exercise and switch off. What more could you want?

I listen to him and feel like heading out for a run. Me, who has never seen the appeal of this sport. I'm so easy to convince. You run for 20 minutes now and you can already feel the effects, he says, especially mentally. 20 minutes you could have spent sitting on the toilet scrolling through TikTok. Great, he makes me feel worse. But how do I establish a routine? That's what I find hardest, really. Try to stick with it for a month or two, three days a week. If you manage that, I don't think you'll give it up. It's a physical and mental therapist. And free, I think.

Maybe I'll have to give it some thought.