About
Coach Peter

My journey

From the ER to the start line.

I was born and raised in Korea for 36 years before coming to the U.S. later in life for a new challenge. I wasn't a natural runner — through my mid-40s, running wasn't part of my life at all. I was focused entirely on work and providing for my family.

That changed when I collapsed at work from a health issue and ended up in the ER. It was a small, hard price for not taking care of myself. A coach from a Korean running club at my church suggested I try running. That's where my running story actually begins.

I couldn't run 1.5 miles without running out of breath. I could barely make it to a club meeting once a week. But slowly, running started to feel less impossible — and then COVID shut the clubs down. Worried about my health, I started running again in a small group, training alongside senior coaches and stronger runners, and that's when I really started learning: not just running, but training.

From miles to method

I got serious about the theory, not just the miles. Pete Pfitzinger's Advanced Marathoning was the book that changed how I understood training — what each type of session was actually for, and why. I started applying that theory to my own training, testing it through real marathon prep, and watching it work. That process — building a plan, testing it, proving it — became something I couldn't stop studying.

My first marathon: 3:05:15. The next year, I brought it down to 3:04. I chased sub-3 after that and came up short at 3:01:47 — but that race taught me more than the ones I finished on target.

Becoming a coach

After years of training, I spent the last year deliberately pulling back — recovering, rebuilding, giving my body the rest it needed. I also volunteer as a coach with 동달모 (DongDalMo), a Korean-American running club in Irvine, OC. Along the way, I found out about the RRCA coaching certification. It looked like a chance to study more deeply and actually help other runners, not just myself. I took the exam, got certified, and that's where I am now: an official running coach.

Why I write training guides

Through my years in running clubs, I kept meeting the same thing — runners who didn't know why they were training the way they were, what each session was supposed to do, or how to train for their own ability level instead of someone else's plan. That gap is why I'm writing training guides: books that lay out exactly what to run each day, why it matters, and a place to track how it's actually going, with my feedback built in. A training log and a first half marathon guide are ready now, and Half to Full, a first marathon plan for half-marathon finishers, is on the way.