My Journey to a Sub-2:50 Marathon

I am a physician at a university hospital, where I divide my time among clinical practice, medical research, and teaching students. Outside of work, however, almost all of my remaining energy is devoted to running. You could probably call me a running addict.
I started this series to document my journey toward breaking 2 hours and 50 minutes in the marathon while balancing a demanding career, family life, and training.
Personal Bests
Marathon: 2:49:30
Half Marathon: 1:21
I have never seriously raced shorter distances.
Before Running
Until the age of 15, I played soccer. After that, badminton became my primary sport, and I continued competing throughout university.
Interestingly, I hardly ran at all during those years. Our training focused on sport-specific movement rather than endurance running, and to be honest, I didn't enjoy running.
Running seemed boring.
Why I Started Running
After graduating from university, competitive sports disappeared from my life.
Instead, work took over.
I loved good food.
I enjoyed drinking.
Gradually, maintaining my body weight became more difficult.
Around 2019, I decided to start running—not because I wanted to become a marathon runner, but because I wanted to earn the freedom to eat and drink without guilt.
At first, I ran only once or twice during weekdays and once on weekends.
Ironically, after my very first week of running, I developed severe pain around my ankle due to tendon inflammation. I remember limping for several weeks afterward.
Eventually, my routine settled into jogging 2–3 km twice during the week and about 5 km on weekends.
My First Marathon
One day, I casually decided to enter a marathon.
At the time, I considered myself naturally fast.
Although I had never actually run long distances, I assumed a marathon would simply be a longer version of jogging.
I couldn't have been more wrong.
My first marathon took 4 hours and 55 minutes.
By the end, I wasn't even jogging anymore.
Walking itself had become difficult.
Even then, I wasn't particularly motivated to improve and continued running only two or three times per week.
The Race That Changed Everything
Everything changed in 2022 during a local marathon.
For some reason, I convinced myself that I was capable of breaking three hours.
Reality was cruel.
During the second half of the race, I spent more time walking than running.
The overwhelming feelings afterward were frustration, disappointment, and regret.
That race completely changed my mindset.
I became obsessed with improving.
Becoming a Runner
I increased my training to three or four weekday runs plus a 15 km long run every weekend.
My lifestyle gradually transformed.
I became an early-morning runner.
On weekends, I often woke up around 3:00 a.m., completed a long slow distance run before sunrise, and returned home by 6:00 a.m.
Running also changed many other parts of my life.
Alcohol clearly affected the next day's training.
Overeating made running harder.
Although I still ate enough to support my training, the original reason I started running—to justify eating whatever I wanted—completely disappeared.
Running itself had become the goal.
Garmin Changed Everything
About six months after becoming serious about training, my wife gave me a Garmin Forerunner as a birthday present.
That watch completely changed my running life.
Before then, I had worn a smart band mainly because I needed to answer emergency calls from the hospital.
The Garmin was my first real GPS running watch.
It has been my training partner ever since.
The best—and perhaps the worst—feature of Garmin is its Daily Suggested Workouts.
Back then, I considered myself a recreational runner.
Running every single day never crossed my mind.
Garmin disagreed.
Every morning it would tell me what to run today.
Then tomorrow.
Then the next day.
It simply assumed that running every day was normal.
Slowly, I began to believe it.
Looking back, that watch pulled me much deeper into the world of distance running.
Chasing Sub-3
My weekday runs gradually increased to around 8 km every morning, and I started incorporating structured quality workouts.
Monthly mileage reached 250–300 km.
At that time, my threshold pace was around 4:00/km.
That spring, I ran a 1:25 half marathon, and for the first time, I truly believed that breaking three hours was within reach.
Finally, in the autumn of 2024, during my local city marathon, I achieved my first sub-3 marathon.
Six months later, at the Osaka Marathon, I finished in 2:49 (net time), finally breaking the coveted 2:50 barrier.
Crossing the finish line was overwhelming.
I actually found myself in tears.
At that time, my training consisted of:
Running every day
Weekly long runs of around 25 km
Threshold sessions at approximately 3:50/km, performed as cruise intervals
The Hardest Part Begins
Ironically, breaking 2:50 was not the end of the story.
It was the beginning of the most frustrating period.
Naturally, I expected to keep improving.
Instead, my next marathon resulted in 2:58, followed by another 2:49 several months later.
Although these were respectable performances, I felt they did not reflect the amount of training I had accumulated.
By then, I was running about 10 km every day, completing 25–27 km long runs every weekend, and improving my threshold pace to around 3:40/km during interval sessions.
On paper, everything suggested I should be capable of running significantly faster.
Yet I wasn't.
During that 2:49 marathon, my race plan was actually to target 2:40–2:45, holding approximately 3:50/km throughout the race.
The first 30 km went exactly according to plan.
Then everything fell apart.
The final kilometers became a battle for survival.
I slowed to around 4:30/km, desperately hanging on until the finish line.
I still broke 2:50.
But instead of satisfaction, I felt disappointment.
Learning to Look at Myself Objectively
Many runners talk about the difficulty of breaking three hours.
I believe everyone's biggest obstacle is different.
I had an athletic background and was fortunate to have a lean build (BMI around 19), which probably made the transition to distance running easier.
However, I eventually reached the point where natural talent was no longer enough.
I had no idea how to train smarter.
Whenever I feel lost, I return to one principle:
Look at yourself objectively.
At that point, I could sustain my threshold pace of 3:40/km for about 20–30 minutes.
According to VDOT, that corresponded roughly to a marathon capability well below 2:45.
So why couldn't I hold 3:50/km for the entire marathon?
The answer became obvious.
I had enough speed.
I simply couldn't maintain it.
A New Training Philosophy
From that moment, my training changed.
Rather than trying to become faster, I focused on extending how long I could maintain 3:50/km.
Throughout May, every key workout consisted of running at 3:50/km for as long as possible.
Initially, I could manage only:
4 km
Rest
4 km
Rest
2 km
Gradually, my body adapted.
The progression became:
6 km + 2 km + 2 km
8 km + 3 km
10 km + 2 km
My ultimate goal was to sustain 12 km continuously at 3:50/km.
Unfortunately, summer arrived before I could achieve it.
The heat made long threshold efforts increasingly difficult.
What's Next?
This is only the beginning.
From here, I plan to continue writing about my training, lessons learned, and ongoing pursuit of becoming a stronger marathon runner.
After all, the journey is often more interesting than the finish line itself.