Sojin Park

1 / 5

	Swim (1.5km)	Bike (40km)	Run (10km)	Total
Result	31:28	1:20:31	57:03	2:55:21

My first triathlon.

Ever since the start of 2025, I’d had a vague desire to get better at cardio. I’d been running consistently, but after years of posting the same times with no real improvement, it was getting boring. I decided I needed to push myself harder with running and, beyond that, expand the scope of my cardio altogether.

As part of that, I decided to take up swimming again after a long hiatus. As luck would have it, I was living in Jamsil, which is surrounded by pools — the Olympic Swimming Pool, Jamsil Pool No. 1, and more. It felt like a waste not to take advantage of that kind of infrastructure. So I started with casual lap swimming on weekends.

Swimming turned out to suit my lifestyle better than I expected. The biggest draw was being able to train in the exact same environment no matter the weather — rain, snow, heat, or cold. The impact on my body was low, and since you always shower after a swim, I’d come out feeling fresh and clean. I became convinced it could genuinely become part of my daily routine.

Sticking with it, my skills improved quickly. I think it helped that my mom had made me do a lot of swimming when I was a kid. Before long, I managed to swim over 2,000 meters without stopping, and I even entered the Han River Cross Swimming Challenge.

Just as my confidence in swimming was growing, I happened to chat with Hyeonsu Lee, a longtime colleague at the company, about triathlon. Hyeonsu, who had kept up with exercise consistently, said triathlon was on his bucket list — but he couldn’t find anyone to do it with him, so he’d been pitching the idea to people around him.

I figured I already had a decent base in both swimming and running, and I rode Seoul’s public bikes around fairly often — how hard could it be? So I impulsively signed up for a race just two months away.

Once I looked into it, I realized triathlon first and foremost required a bike — and not just any bike, but a road bike. I bought what looked like a decent one off Daangn Market. Riding a road bike for the first time felt completely different from what I was used to. It was fast, but keeping up a continuous pedaling effort was hard. On my first ride, my average speed was around 27 km/h, and I was wiped out after just 30 minutes. The race would require 40 km — and the thought of sustaining that effort for an hour and a half straight was daunting. I clearly had a lot of cycling practice ahead of me.

Fortunately, through a relative’s recommendation, I found a triathlon class called O Class. The schedule — 5:00 to 7:30 in the morning — was no joke, but it was a great program where I could train for all three disciplines in one place.

Over roughly a month, I focused intensively on cycling in particular. Along the way, I learned for the first time that there’s a concept in cycling called power. At first, I struggled to hold 120W for even 30 minutes, but my fitness steadily improved. By the time I lined up for my first race, I had pushed my FTP up to around 180W.

For a debut race, finishing in 2 hours and 55 minutes was a solid result. Having a decent base in swimming and running helped, but I also had Younghwa Kang — a former colleague from Toss — and several others come out to cheer me on. Exchanging shouts of encouragement with friends along the course made all the difference.

That race was what got me truly hooked on triathlon. Since I was still a beginner in all three disciplines, my fitness kept climbing in direct proportion to the time I put in. On top of that, swimming, cycling, and running all draw on the same cardiovascular and aerobic engine, so training in one discipline naturally lifted the others. For the first time, I got to experience the genuine thrill of swimming and running at speeds I never thought I was capable of.