Jan Castillo is one of those people who immediately make you terribly envious. The first thought that comes to mind after meeting him is an obvious yet inevitably jealous question: how can he maintain such an active sporting life while being a third-year medical student (who actually passes his exams)?

At 12, he started running some weekends along the paths around Collsuspina, and today he is an 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 a medical career with a sporting one. I look at him and can't quite believe it's possible, but then I remember that he is already managing 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 pursue it professionally, it will always be my hobby. I will never stop running. He finishes the sentence, and it strikes me as a very beautiful way of seeing the glass as half full. That's what stands out about Jan. Optimism as his trademark.

For some time now, I've been bewildered by the fact that everyone runs these days, and I take the opportunity to discuss it with him. What's going on that my friends now run 10-kilometre stretches on any peaceful Sunday afternoon? Why do I keep seeing 'running clubs' everywhere? Are they here to stay, or are we still dealing with the hyperactivity left over from a foggy lockdown we've already forgotten? Jan is clear about it: this is here for the long haul. It's an inexpensive, addictive sport with flexible hours that's easy to practise. It makes sense, of course. And running clubs are the same: people leave the house, socialise, exercise and switch off. What more could you want?

I listen to him and feel like heading out for a run. And I had never seen the appeal of this sport. I'm so easy to convince. You run for 20 minutes now and you already notice the effects, he says, especially mentally. Twenty minutes you could have spent sitting on the toilet scrolling through TikTok. Great, now I feel worse. But how do I establish a routine? That's what I really find most difficult. 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 should give it some thought.