Running Mate
"First of all, the most important thing in running is how your foot lands."
"Lands?"
"Want to try running a bit right now? Just a few steps."
"Yeah. Okay."
I set my form the way I always did and started running. It was a form I'd pieced together after digging around online, and I'd thought it was solid enough.
After I'd taken a few strides forward, she watched me with a low hum of consideration, then stepped up beside me.
"Your stride's too long. Your foot's reaching too far out in front. Keep going."
"I get that you want to cover ground fast, but you can't run for long like that."
"Seon Woo-hyun. I'll show you what you look like when you run. Watch."
She locked into a clumsy posture and bounded forward with exaggeratedly long strides. It was a world away from the form she usually ran with.
"Feel how the center of gravity tips when you run like that? Your feet can't absorb the impact properly, so you burn through stamina way too fast."
"The right form is like this. Plant your heel directly under your center of gravity, and land with your leg vertical to the ground."
The moment she slipped back into her usual form, the landings became stable and light. Even after just a few steps, the difference in control was glaringly obvious.
...I'd been running like that?
I'd thought I looked pretty sharp. Watching her reenact my form was honestly a little shocking.
"Not forward—down. Think of it as stepping on the ground that's right under your body."
"And your posture's too hunched. Chin tucked, chest open. Your head should be looking straight ahead, not at the ground."
Breathing. The impact traveling through the hamstrings and lower back. Then the mistakes in my arm swing. She stood me up in a running stance and adjusted every piece of me by hand until the form was correct.
Moving the way she told me to, I eventually settled into a posture that felt strangely awkward. It was so much like holding a statue's pose that I had to ask.
"Do you really have to run in a position this uncomfortable?"
"...The fact that it feels uncomfortable just means your usual form was that messed up."
"Ah."
"Run like that and it doesn't matter how much stamina you have—you won't last. That's why you can never keep up with me."
Her explanations were scientific and precise. Every single point was so airtight I couldn't argue with any of it. All I could do was nod along, a little amazed.
"Okay. I get what you're saying. I'll try running like this."
"Good. Once you feel it in your body, you'll notice the difference. Let's go."
I started running, fighting to hold the form she'd corrected for me.
"Stride's getting long again."
"Posture. Eyes forward."
"Your arms are swinging too far in front of your body. More to the back."
Like a trainer jogging right beside me, she kept watching and correcting my form the entire time we ran.
I was thrashing through the run, my stamina almost completely drained, when—
"Stop. Let's cut it here."
At Seo Da-eun's stop signal, I planted myself right where I was. Then I collapsed onto the ground, gasping for air.
"Hah... hah... Seo Da-eun... I think I'm dying..."
"You're not dying. Relax. In all my time on the track team, not a single person has ever died from running."
Cold as ice.
Completely different from the girls I'd been hanging around with. That extreme T-type reaction, pure athlete through and through, actually snapped me back to my senses.
Sweat rolled down my cheeks in thick beads. My breathing was so shallow my head spun, my heart hammered, and my throat burned with thirst. And yet, somehow, I felt good.
Runner's high, was that what they called it? After pushing through the pain and finishing the run, dopamine was flooding my brain.
"Good work. Here. Drink."
She held her water bottle out to me first. She already knew I never brought my own. Usually we'd take turns detouring past a convenience store to buy something—carrying a bottle around was just a hassle.
On a normal day I might have hesitated about putting my mouth on someone else's bottle. Right now I didn't have the bandwidth for that. I sealed my lips over the spout and poured the water down my throat.
Gulp. Gulp.
As the moisture flooded into my body, pure pleasure surged up like a downpour. Water—something I drank without thinking every day—had never tasted this sweet.
"Khh."
She watched my face and that little sigh of bliss, then let out a short laugh.
"Well? Water taste good?"
"Hooo... Yeah. Insanely good. I had no idea water even had a flavor."
"Everything tastes better after a workout."
Then she brought the same bottle to her own mouth. I caught the faint sheen of her lips settling over the spot mine had just touched, and something about it made me look away, suddenly embarrassed.
Seo Da-eun, though, drank without a single thought—gulp, gulp—then screwed the cap back on and tucked the bottle into the sports bag she always carried. She settled down lightly beside me and spoke like she couldn't wait another second to tell me.
"Shall we measure the results?"
"Results?"
"I mean comparing it to how you usually run. You said it yourself—somewhere between ten and twenty minutes, you start falling behind me."
"Yeah."
"Check the time."
I pulled out my phone and looked. I couldn't help being stunned.
It was 6:40 a.m. I'd left the house around 5:30 and met up with her. Subtracting the short stop for form correction—
"We started running around six, right?"
"Yeah."
"Then you just matched my pace for forty minutes. That's double your usual."
"...Huh. You're right."
"And take a look at my face."
The sudden request to study her face made my heart skip for a second before I could stop it. I knew that wasn't what she meant, so I turned and examined Seo Da-eun properly.
Her breathing was rougher than usual. A hint of fatigue showed through. She was sweating about as much as I was—though she wasn't anywhere near as close to death as I felt.
"Can you tell? That I'm struggling."
"...So you are human after all?"
"What did you think I was, normally?"
"A running monster that only exists to run."
"What are you even saying."
She laughed, half in disbelief. But I understood why she was telling me this. It meant I'd run well enough to tire her out, even a little.
And she was a former track athlete.
I looked at her, genuinely amazed.
"Just changing my form a little did all that?"
"Yeah. Exactly. In your case, being tall already made matching my tempo easier, but still."
"..."
"Running isn't actually that hard. People just can't stick to the basics, so they get tired fast and quit. It's a shame."
"..."
"When you run, your form falls apart so easily, and you never really notice it yourself."
"True. I never would have known if you hadn't been right there."
It had only been possible because she'd kept correcting me while we ran side by side. Once your body and mind are exhausted, looking at your own form objectively becomes impossible.
"In that sense... Seon Woo-hyun, you're pretty impressive."
She looked at me the way you'd praise a kid for doing well, fond and approving. The more I saw that expression, the clearer it became how much she loved this sport.
She wasn't getting paid. It wasn't making her any faster. And still, just watching the person next to her improve was enough to put that satisfied look on her face. For someone like me, who'd never chased a goal that wasn't money, it felt pretty remarkable.
"That's just because I have a great teacher."
"That part's true."
"I compliment you and suddenly the humility's gone."
"I was never that humble to begin with?"
We traded jokes, laughing under our breath. I hadn't felt especially distant from her before, but after running this long together, something like camaraderie had settled in, and she felt a lot closer.
Maybe that was another one of running's charms.
I said what I was thinking, pure and simple.
"You're amazing."
"About what."
"Just... being good enough at running to teach other people. And loving it that much."
"..."
"I don't really have anything I'm that good at, or that into."
If I had to name something, it would be nine years of factory work, and maybe badminton. I had hobbies like reading novels, but I'd never poured myself into chasing something with real passion. I'd made it all the way to twenty-nine like that, so watching someone this sure of what she wanted made me a little envious.
I said it with a serious face. Seo Da-eun studied me quietly for a moment, then—
"Then start now."
"Huh?"
"You can start liking running from now on. And I've seen you play badminton a bit, too."
"You saw that?"
"Yeah. From a distance, roughly."
She seemed to decide the break was already over. She gathered herself and stood, then looked down at me.
"If you're interested in running, make me your goal."
"You?"
"I don't go all-out on morning runs, so it should be doable. Aim for about an hour and a half."
"..."
"Let's try matching pace every day and finishing the full Yeongseong Stream loop. Out and back through our neighborhood, the course takes about an hour and a half."
Was she trying to help me fall in love with running? She'd even set a goal for me. The fact that she looked cool for it was probably just my imagination—but that sweet attitude under the cool face was enough to make me fall for her without meaning to.
I honestly didn't have the confidence to do it alone, so the question slipped out before I could stop it.
"So you'll keep coaching me until then?"
She turned her head, let out a short laugh, and said—
"If you want?"
I want. Of course I want.
I nodded so hard and fast I looked like a flapping penguin.