Running, CrossFit, and Other Things I Never Saw Coming

I developed a growing interest in physical activity during my postdoctoral years, not because I fell in love with one specific sport, but because I discovered that I enjoy trying a little bit of everything.

Running was where it all started. Around the end of my PhD in 2020, I completed my first 5K. At the time, I was living with my friend Archit while waiting for my visa to Sweden to arrive. There was a park nearby where we would go for runs together. Back then, even 3 km felt like a serious achievement. I remember faithfully following the Nike Run Club app, especially the famous “First Run” guided session that lasts 20 minutes. I repeated those guided runs many times and slowly improved. When I moved to Sweden, I kept running on and off. It never became effortless, but that’s probably why I still feel proud every time I go out for a run.

Around the same time, I started going to the gym once or twice a week at KTH’s campus gym. My gym journey actually began earlier during my PhD at UIUC. Funnily enough, my first experience with the gym was thanks to my friend Andreas, who showed me how to use a treadmill. Later, I took a few personal training sessions with an undergraduate student who charged around $20 per hour. At the beginning, I could barely do one pull-up. After a few months, I managed to do eight in a row, which felt almost superhuman to me at the time.

I would love to say that I maintained those gains forever, but then COVID happened, routines disappeared, and I found myself starting over in Sweden. In some ways, though, starting over turned out to be a good thing.

Things changed when my wife, Renfei, discovered an app called Bruce in Sweden. The app gives access to an incredible variety of gyms and classes, from regular gyms to CrossFit studios, for a fixed monthly fee. We were amazed by the idea that we could try almost anything without worrying about individual memberships. At first, we were probably motivated by getting our money’s worth and improving our activity streak in the app, but something else happened: we genuinely started to enjoy it.

Renfei had already started CrossFit in Amsterdam, and she encouraged me to give it a try. What started as an experiment quickly turned into a routine. By the end of 2023, we were going to classes four or five times a week, sometimes even more. We felt stronger, healthier, and, perhaps most importantly, we were having fun.

Getting fitter had some unexpected side effects. In 2025, we completed our first half marathon: not once, but three times. Looking back at the person who thought 3 km was a major accomplishment, finishing a half marathon would have sounded completely impossible. And yet here we are, signed up for a full marathon in 2027.

The exercise journey also took us beyond gyms and races. We spent a week hiking Kungsleden in northern Sweden, carrying our backpacks through some of the most beautiful landscapes I have ever seen. It is funny how a small habit, going for a 20-minute run in a local park, can eventually lead to adventures like that.

Perhaps the best side effect of all has been the people. Working out, especially through CrossFit, has introduced me to many interesting and inspiring people from different backgrounds. Some of my favorite conversations in Sweden have happened while cooling down after a workout or catching my breath between sets.

I still wouldn’t call myself a natural athlete. Running is still hard, burpees are still terrible, and every now and then I have to rebuild habits from scratch. But somewhere along the way, exercise stopped being about appearance or checking a box and became a source of adventure, community, and joy. And that has been one of the most pleasant surprises of my postdoc years.