I started Doctor After 50 for a simple reason: I turned 50.
For most of my adult life, I considered myself physically capable. I worked as a thoracic surgeon, stayed active, trained regularly, and continued kickboxing into my late 40s. I have also spent years around professional fighters and champions, and I still train in serious gyms while living in Cambodia.
Then I suffered a muscle injury during training.
It was not a dramatic event, but it changed the way I looked at my body.
I was fit. I had stamina. I could still train hard.
But I realized that physical fitness does not make us immune to age-related changes in muscle, strength, and recovery.
When Research Became Personal
That realization was especially striking because I already knew the science.
I am a thoracic surgeon and physician-researcher, and part of my academic work has focused on sarcopenia, skeletal muscle, body composition, and outcomes in patients with cancer.
I have conducted and supervised original clinical research examining muscle loss before and after lung cancer surgery, CT-based assessment of skeletal muscle, and the relationship between sarcopenia and long-term outcomes.
Our work has also explored possible biological links between skeletal muscle, myokines, immune function, and cancer progression.
Now I am continuing this line of research in Cambodia, including studies of muscle quality, myosteatosis, fat distribution, metabolic health, inflammation, and surgical outcomes.
After 50, Muscle Quantity Is Only Part of the Story
I am not interested in becoming as large as possible.
I am interested in something different:
strong muscle, good muscle quality, mobility, cardiovascular fitness, recovery, and a body composition that can support health and physical independence for decades.
Body weight alone does not tell that story.
Neither does BMI.
And simply having more muscle may not tell the whole story either.
After 50, I believe we need to think more carefully about what kind of muscle we are building and preserving.
Why I Train
Over several years, I deliberately reduced my body weight before gradually rebuilding it. Around the age of 50, I then intentionally increased my weight while focusing on strength, protein intake, bodyweight training, aerobic fitness, and recovery.
My goal is not simply to weigh less.
It is to learn how to control my weight, strength, fitness, and body composition rather than letting age decide them for me.
I want to continue working, thinking, moving, and challenging myself for as long as possible.
My personal target is simple:
Build a body that can last toward 100.
What You Will Find Here
Doctor After 50 explores:
- strength and bodyweight training after 50
- sarcopenia and age-related muscle loss
- muscle quality and myosteatosis
- body composition and metabolic health
- protein, nutrition, and recovery
- cardiovascular fitness
- lessons from cancer and surgical research
- practical experiments from my own life after 50
This is not a bodybuilding site.
It is not simply a weight-loss site.
It is an ongoing exploration of how to build a strong, capable, metabolically healthy body that can keep working for decades.
Selected Research
Clinical Impact of Sarcopenia 1 Year After Surgery for Patients with Early-Stage Non-small Cell Lung Cancer
Annals of Surgical Oncology, 2022
Original research examining the development of sarcopenia after lung cancer surgery and its association with long-term outcomes. Corresponding author.
Clinical Utility of Psoas Muscle Volume in Assessment of Sarcopenia in Patients with Early-Stage Non-small Cell Lung Cancer
Journal of Cancer Research and Clinical Oncology, 2023
Original research evaluating CT-based muscle volume and the relationship between sarcopenia and cancer outcomes. Corresponding author.
ASO Author Reflections: Management to Prevent Postoperative Sarcopenia in Patients with Lung Cancer
Annals of Surgical Oncology, 2022
A clinical reflection on preventing and managing muscle loss after lung cancer surgery.
Research taught me what aging can do to muscle.
Experience made it personal.
Turning 50 made me start designing what comes next.
Yoshihisa Shimada, MD, PhD
Thoracic Surgeon and Physician-Researcher
Research interests: sarcopenia, body composition, muscle quality, and cancer outcomes