About
Andrew Irwin, MD, CSCS
Internal medicine physician. Certified Strength and Conditioning Specialist. Ironman and Hyrox competitor. I am building Vital Capacity as a future performance medicine practice for adults who train seriously and want deeper testing, clearer interpretation, and medical follow-through.
Origin
My path into this work started at Dalhousie University, where I studied kinesiology before medical school. Before I ever wrote a prescription, I was paying attention to movement: gait, mechanics, strength, compensation patterns, and the way bodies adapt under load.
I worked as a personal trainer through that period and into early adulthood. That taught me the difference between writing a program and understanding the person in front of you. It also showed me where coaching stops: the point where labs, medications, family history, symptoms, and medical risk become part of the answer.
Internal medicine gave me the other half of the frame. It is the field where labs, symptoms, medications, family history, imaging, lifestyle, and risk have to be reconciled into a single plan. That is the work I care about: extending the years a person stays strong, capable, and functional.
Personal training
What years of training real people taught me.
"STOP." I had just figured out why someone I was training had persistent knee pain. "Stand up exactly how you just did, again." She stood up from the dumbbell bench, looking puzzled, with her feet tucked far back behind her knees. The cause was now clear. "All of those squats and lunges to strengthen your muscles won't help if we don't correct your everyday movement patterns first." I showed her how to place her feet under her knees when rising from a seated position — reducing torque at the knee, engaging the glutes instead. After two weeks of intentional standing, she never mentioned the knee pain again.
Years of training real bodies builds a kind of eye you don't get from a textbook. You see the gait patterns that predict injury. You catch the compensations that mask weakness. You learn the difference between a program that looks good on paper and one that fits the person actually doing the work. And you watch what happens over time — month after month, year after year — when the small things are right.
- A man whose tears caught him off guard the first time he saw what consistent training had changed about his body.
- A pregnancy made smoother by the metabolic work done before it.
- A woman in her sixties who reclaimed multi-day backcountry hiking she had given up on.
- A psychiatrist who pushed me toward medical school — because he could see where coaching was reaching its limit.
Coaching gave me the eye. Medicine gave me the responsibility.
What I have seen in practice
Two patterns repeat. High-performing adults walk out of routine physicals with normal-looking labs, while the things actually holding them back — a heart-disease marker climbing in the background, an early sign of insulin trouble, a fitness number lower than expected, muscle quietly being lost behind a normal-looking weight — sit hidden in tests that were never ordered. Modern medicine is very good at diagnosing disease once it has declared itself. It is less often built to enhance health, preserve capacity, and prevent disease before it becomes obvious.
I also see the other end of the timeline in hospital medicine: people whose bodies are too weak to tolerate the treatments meant to save them. The athletic twenty-year-old and the frail seventy-year-old can be the same person separated by decades of training, nutrition, sleep, injury, illness, and medical decisions. The trajectory is rarely random.
I have also practiced in remote locations like the Himalayan villages of northern India, with no internet and no backup. That experience reset what I think a physician's job actually is. It is not simply delivering information. It is taking responsibility for the next decision when the data is incomplete and the patient is in front of you.
Why I am building Vital Capacity
Vital Capacity is being built around a simple gap: fit adults often receive medical care from people who do not understand training, and training advice from people who cannot practice medicine.
Our founding patients will start with a deep diagnostic assessment: records, advanced labs, DEXA body composition, VO₂ max testing, strength and recovery metrics, training history, family history, medications, symptoms, and goals. The point is not to collect more data. The point is to decide what matters most and what should happen next.
The core focus is integration:
- Training and strength treated as part of medicine, not as hobbies
- Injuries, movement quality, and how much your body can take
- Cardiorespiratory fitness and long-term cardiovascular risk
- Blood sugar, cholesterol, and how your body handles fuel and weight
- Staying capable, decade after decade
The goal is not testing for its own sake. It is helping committed adults stay strong, healthy, and capable for longer — with one physician connecting the medical side and the training side over time.
Athletic identity
Training is not a hobby added onto the practice. It is part of how I think. Two decades of competitive training have made the trade-offs concrete: fatigue, injury risk, race goals, family life, sleep, nutrition, and the cost of trying to get better.
Credentials
- Doctor of Medicine — Columbia University, Internal Medicine
- CSCS — Certified Strength and Conditioning Specialist (NSCA)
- Master of Science — McMaster University, Global Health with specialization in Public Health Policy
- Bachelor of Science — Dalhousie University, Kinesiology with specialization in Exercise Physiology
Follow the work
Follow the work. Decide whether this is your kind of medicine.
Vital Capacity is a newsletter about clinical science, human performance, and the integration of medicine and training. Founding patients have not been accepted yet; the clinical approach is being built in public.