About the Author — My Running Journey

Hi there! I’m Shuichi, the author of Running Scientist.

On this blog — Running Scientist — I share the science-based training principles I practice myself as I work toward my personal records. My goal is to push the limits of performance within real-world constraints: a full-time job, a family, and a tight schedule.

Alongside training theory, I also cover elite runner approaches, exercise physiology, and running gear reviews — everything a serious recreational runner needs to keep improving.

My commitment is accuracy. I only share information I can stand behind.

I believe the most trustworthy information comes from direct personal experience. In a world overloaded with running advice, I aim to cut through the noise and help you improve through evidence-based training.

My focus: reaching performance goals as efficiently as possible. From the wealth of theories and methods available, I select and apply what works best — and share the results with you.

I hope Running Scientist becomes a resource that helps you surpass your past self and achieve the goals you’re chasing.

On this page, I’ll introduce myself — my background, athletic history, injury experiences, and what this blog is here to do.

About Me

I work as an engineer at a manufacturing company.

My work hours are 8:30 AM to 5:15 PM. I’m married with children, and both my wife and I work full-time — so finding time for hobbies takes some creativity.

I train almost exclusively in the early morning, finishing my run before my family wakes up.

I grew up playing sports, so I have a decent aerobic base — but long-distance running was essentially new territory for me.

A few years into my working life, I discovered the power of structured, science-based training and started setting personal records consistently. That experience hooked me.

I decided to commit to one question: how far can I push my performance within the limits of my time?

My Training Philosophy: Daniels’ Running Formula and the Lydiard Method

What got me serious about running was discovering Daniels’ Running Formula. Following its structured training system, I started hitting personal records I never thought possible.

“I can’t believe a framework like this exists,” I remember thinking.

I later encountered the Lydiard Method — the approach adopted by Coach Harada of Aoyama Gakuin University.

Looking at the training programs of Japan’s most well-known marathon coaches, virtually every one of them traces back to either the Daniels system or the Lydiard system.

If you’re a recreational runner serious about improvement, I believe both books are essential reading.

My Running Journey

Here’s a look at my athletic history, from childhood to today.

Elementary and Junior High School: First Marathon Race

I joined a soccer club in first grade. I was pretty overweight and kept making mistakes — and getting yelled at for them.

In fourth grade, a coach told me to lose weight for the first time. Between fall and New Year’s, I dropped about 3 kg. My height was growing while my weight dropped, so at the next health checkup, I was actually called in for being underweight.

In sixth grade — I don’t quite remember how it happened — I entered a 5 km race and ran it in 20:36. That was my first ever road race.

Looking back, that was actually a pretty solid time for someone who had done almost no structured training.

In my third year of junior high, I was running 1500m somewhere between 5:00 and 5:30 on a sand track. I was fast by class standards, but nothing compared to actual track athletes.

I continued playing soccer through high school. We didn’t have timed distance runs in P.E., so I’m not sure exactly where my endurance stood — but soccer training was intense and included a lot of running, so my fitness held up.

University: Track & Field — and an Injury That Changed Everything

In university, I joined the track & field club (competitive team). I chose the long jump — I remembered being decent at it in junior high, and figured I could make it work.

Through my sophomore fall, my results improved steadily, getting close to a level where competing in the prefectural championships seemed realistic (6m79cm).

Then, during winter training in my second year, inflammation at the connection between my ischium and hamstring tendons flared up badly. From that point on, I couldn’t train the way I needed to — and my results stalled. I graduated without ever fully recovering.

This ischial tuberosity injury had first appeared in junior high and kept coming back — through soccer in high school and track in university, it affected both.

That experience taught me two things: what overtraining-induced injury really looks like, and how critical it is to train consistently without getting hurt.

After retiring from track in September 2013, I still had the rest of university ahead — and I asked myself what I could do in parallel with my research. The answer I landed on was running.

That was the beginning of my running journey.

My lab had core hours from 9:00 AM to 6:00 PM, Monday through Friday, so I trained before or after. In December 2013, I ran a half marathon in 1:25:39. In January 2014, I ran a 10K in 37:24.

Looking back, I made solid progress for just two or three months of training.

My training at the time? Basically just running. Same course, arbitrary pace, probably every other day or so — nothing structured.

Working Life, Years 1–3

I kept running into my first year of work. I had wanted to play futsal, but rotating shift schedules made that impossible, so I stuck with running.

My training was still unstructured — jogging and some intervals with no real pace targets. At the Katsuta Marathon in January 2015 (Year 1), I ran a 10K in 37:16.

A small improvement over my time a year earlier, but not much for the training I was putting in. Around that point, I stopped running altogether.

Working Life, Years 4–7 (2017–2021)

During my hiatus from running, I shifted focus to strength training — always one of my hobbies.

With a change in work location, I finally joined a competitive futsal team in 2017 and played in the prefectural league.

But I got married in January 2018, and lifestyle changes made it difficult to keep up with futsal. I stopped after about a year.

In January 2018, a road race was held near my workplace. It was subsidized by my company, so I entered for free. I wasn’t serious about racing at that point — just showing up.

I had decent fitness from futsal, but someone in a different department was genuinely fast — and he beat me in the 8K race. I couldn’t stay with him past the first kilometer. I finished in 33:19 — slower per kilometer than I had been in sixth grade.

The combination of losing and realizing I’d gotten slower lit a fire in me. I decided I’d win the same race a year later.

About ten months later, I started serious running training in December 2018. At the January 2019 race, I beat the person who had beaten me the year before. My time: 30:32 for 8K.

“I can’t believe I got this fast in under two months,” I remember thinking. That was the moment running took over.

Unlike my earlier attempts, this time I planned training content and target paces based on Daniels’ Running Formula.

By April 2019, I ran a half marathon in 1:22:45 — a new personal best, just four months in. From 2019 onward, I kept improving consistently.

My first sub-1:13 half marathon came in October 2021. Up to that point, I had followed the kind of accessible training described in Daniels’ book — workouts any runner can replicate.

Here’s my half marathon progression through early 2022:

I also got serious about the 5000m starting in 2020 and began competing in certified track races from 2021.

Progress was steady throughout this period.

Working Life, Year 8 (Late 2022–2024)

From 2022, my results stalled — and things got tough.

My 5000m PB came in 2022, but in the half marathon, the fastest I ran all year was 1:13:59 at the Ibi River Half.

Then in January 2023, I suffered a serious injury: severe sciatic nerve pain originating from the piriformis and quadratus femoris muscles in my hip.

For about four months, I couldn’t run at all. My weight went up and my fitness dropped sharply.

I worked through rehabilitation and eventually resumed serious training around July 2023.

In 2023, my best was in the 1:17 range. Through 2024, I managed only 1:16 — still well off my personal best.

The root cause of the stall is clear to me now. Around the end of 2021, I introduced a new training method.

It was the double threshold training famously associated with Jakob Ingebrigtsen — two threshold sessions per day. I copied it without doing any real research.

The result: a PB at the 2022 Nagoya City Marathon in March — followed by stalled progress, accumulated fatigue, and ultimately the serious injury in January 2023 that I believe was driven by overtraining.

Not understanding the theory behind what I was doing — why it works, what it demands from the body — is something I deeply regret.

On the other hand, it pushed me to study training theory and exercise physiology more seriously than ever before.

2024 Onward

After recovering from the injury and returning to training, I committed to threshold training the right way.

I acquired a Lactate Pro 2 blood lactate meter and began exploring a version of double threshold training that actually works for a recreational runner.

The first thing the lactate data revealed: my previous training had been running at far too high an intensity. The injury, in hindsight, was inevitable.

From October 2023, I started searching for the right intensity level for my own body. Getting the load right — hard enough to adapt, easy enough to avoid accumulating damage — took months of trial and error. The honest question I was chasing: can recreational runners actually sustain double threshold training?

In August 2024, I finally found what I was looking for — an intensity where I could accumulate meaningful volume without excessive fatigue.

2024 didn’t produce a new PB, but my fitness was clearly trending upward. I also ran my first full marathon: 2:43:55 at the Tsukuba Marathon in November 2024.

The 2025 race season hasn’t fully started yet, but I expect to get close to my previous bests in the October–December window.

Injuries Along the Way

As the history above shows, my progress has not been a straight line. Injury has been the single biggest obstacle.

Simple fitness improvements slow down as you get faster — but the biggest disruptions have always come from injury-forced breaks. Here’s a summary of what I’ve been through.

Ischial Tuberosity (Hamstring Origin) Inflammation

This first appeared in my third year of junior high, during soccer. I noticed pain at the very top of my hamstrings — the attachment point at the sitting bone.

Kicking a ball and short sprints were especially painful — pretty devastating for a soccer player.

Resting didn’t seem to help much. Looking back, I was only doing surface-level treatment without any real rehabilitation — that’s probably why it never fully healed.

A full year off sport for university entrance exam prep finally let it calm down. But it flared again in my second year of university and significantly affected my track career.

It came back once more years later during my futsal years.

I eventually decided to take active responsibility for my recovery — adding ultrasound therapy and foam roller myofascial release — and today I can run long distances without any meaningful pain in that area.

Today, I don’t feel meaningful pain near the ischial tuberosity during long-distance or marathon-level training.

Knee Pain

In December 2020, I paced a friend’s sub-3-hour marathon attempt with almost no specific preparation. I ran the full 42.2 km at an easy effort — more like a long training run than a race. I completed the pacing as planned and technically achieved a sub-3 in training.

But the accumulated stress caused a knee injury.

By the time I fully recovered and returned to my previous fitness level, roughly six to seven months had been lost. I thought I was being careful — but I underestimated the risk.

After that injury, I made a commitment: “I will not get injured again.” I re-examined the factors that caused it, revisited how I think about workout intensity and weekly volume, and now build every training plan with injury prevention as a non-negotiable constraint.

Sciatic Nerve Pain (Piriformis and Quadratus Femoris)

In January 2023, I developed severe sciatic nerve pain caused by the piriformis and quadratus femoris muscles in my hip. For about three to four months, I could barely run at all.

Rest alone didn’t help. I started acupuncture treatment, and by late April I was slowly, carefully, getting back on my feet.

By June 2023, I still wasn’t fully recovered — nowhere near my normal training speeds or mileage.

Around August 2023, the pain had reduced enough to resume serious training. Acupuncture was by far the most effective treatment.

Even into 2024, residual discomfort in the deep external hip rotators (including the piriformis) persisted — flaring up with hard training sessions.

With fitness still below where I wanted it and recurring pain, I wondered whether something in my running form had gone wrong.

By 2025, the sciatic nerve pain had improved significantly. The two changes that made the most difference: deliberately increasing my running cadence, and adjusting my training load to a level my body could actually absorb.

I had always been a stride-dominant runner. My working theory is that I was landing too far in front of my center of mass, placing excessive load on my glutes. By forcing my cadence higher, my foot strike naturally shifted closer to under my hips — and the post-training flare-ups gradually faded.

As of late 2025, even high-intensity training sessions no longer trigger sciatic pain.

What This Blog Is About

As I said at the start: I hope Running Scientist becomes a resource that helps you surpass your past self and achieve the goals you’re chasing.

Some runners have great natural instincts — they land on the right training intuitively, and their times keep improving. But that’s not everyone.

I experienced injury-driven setbacks as a student athlete.

“Train consistently, without getting hurt.”

I believe this is the single most important principle in long-distance running improvement. Consistency is everything — and injury is its greatest enemy.

My personal goal is to find out how fast I can get by training rigorously on an evidence-based foundation — starting from zero background in long-distance running.

The results have been encouraging. Since getting serious about running as a working adult, my times have improved in ways that consistently surprise me.

I don’t think I have special talent for distance running. I’m not particularly small — at nearly 180 cm, I’m statistically on the larger side for elite marathon runners. I have a full-time job, a family, and children. The time I can dedicate to this sport is limited.

And yet: consistent, correct training produces results. I want to prove that with my own body.

My hope for this blog is simple: by sharing my training content, thinking, and methods, I can help someone who wants to keep getting faster — starting from wherever they are right now.

I’ll always prioritize accuracy and honesty — sharing what’s true, based on evidence and lived experience, not what sounds good.

If you’re curious about the science behind running performance, start with the Training Theory or Exercise Physiology sections.