Physical Activity: The Most Underrated Medicine in the World

1. Humans were never designed for chronic inactivity

One of the simplest ways to understand physical activity is to stop seeing it as a hobby and start seeing it as part of normal human design.

For most of human history, movement was not a lifestyle choice. It was built into daily survival: walking, carrying, climbing, hunting, gathering, working, adapting. Modern life removed much of that necessity. Biology did not update itself just because chairs, cars, screens and convenience arrived.

That is why inactivity is not neutral. It is not a harmless default setting. It creates a mismatch between the environment our bodies were shaped for and the one many of us now live in.

That simple shift in perspective changes the whole conversation. Physical activity is not extra credit. It is part of what the human organism expects in order to stay functional.

2. Movement is one of the strongest signals the brain receives

Physical activity is often reduced to muscles, calories and body weight. That is far too narrow.

The brain responds to movement. Exercise is associated with neuroplasticity, better regulation, better cognition and beneficial changes in factors such as BDNF. In plain English: movement tells the nervous system to stay adaptable.

Want a deeper explanation of BDNF and how physical activity affects the brain over time? Read my full breakdown here: Activity-Based Neuroprotection – explained simply .

That matters for healthy people, and it matters even more when the nervous system is under pressure. It is also why this page links so naturally to my broader work on activity-based neuroprotection.

3. The cardiovascular, metabolic and mental-health argument is overwhelming

The evidence base for physical activity is unusually broad. Regular movement is consistently linked to lower risk of cardiovascular disease, type 2 diabetes, several cancers, poorer metabolic health, depression, anxiety and premature death.

It also improves fitness, and that matters more than many people realize. Cardiorespiratory fitness is one of the strongest long-term predictors of health and survival ever studied in lifestyle medicine.

One of the biggest modern mistakes is treating physical health and mental health like separate universes. They are not. Movement affects mood, stress regulation, energy, resilience, attention and how people function in real life.

What does the science actually say?

Below are five cornerstone examples that help explain why physical activity deserves to be treated as one of the most important interventions in all of health.

1. The Lancet physical inactivity analysis

One of the most cited global analyses on inactivity estimated that physical inactivity contributes substantially to non-communicable disease and premature mortality worldwide. This is one of the clearest reminders that inactivity is not some small side issue. It is a real public-health burden.

2. The Harvard Alumni Health Study

This long-running cohort work showed a strong inverse relationship between physical activity and mortality. The pattern was not magical and all-or-nothing. It was graded. In other words, more consistent movement over time was associated with better outcomes.

3. The Aerobics Center Longitudinal Study

This body of work helped establish cardiorespiratory fitness as one of the strongest predictors of long-term survival. That matters because it shifts the conversation away from aesthetics and toward actual physiological capacity.

4. Exercise and depression meta-analyses

Large systematic reviews and meta-analyses have found that exercise meaningfully improves symptoms of depression, anxiety and distress across many adult populations. That does not trivialize mental illness. It elevates movement to where it belongs in the conversation.

5. World Health Organization guidance

WHO recommendations are not built on one single paper but on a broad evidence base. Their guidance links regular physical activity to lower risk of major chronic disease, better brain health, reduced symptoms of depression and anxiety, and better overall function.

Why is something this powerful still so underused?

This is where the argument becomes uncomfortable.

If the evidence is this strong, why is physical activity still treated by so many people like optional lifestyle decoration instead of something much closer to foundational care?

Part of the answer is practical. Movement requires effort, repetition, patience and behavior change. It cannot be outsourced. It does not come in a box. It does not create the same immediate psychological comfort as “I have taken something, therefore I have acted.”

Part of the answer is structural. Healthcare systems are much better designed to diagnose, prescribe, monitor and scale medication than they are to help people build sustainable daily habits.

And part of the answer is emotional. Real change is uncomfortable. It forces people to confront fatigue, inertia, perfectionism, fear of failure, embarrassment and the gap between what they know is wise and what they are actually doing.

That is also why Kjerpeset’s framing hits so hard. If this were a pill with comparable broad effects, it would likely be treated like a medical breakthrough. But because physical activity must be done rather than swallowed, it is too often ignored, postponed or reduced to background advice.

It started with MS, fatigue and a life that was becoming too expensive

My story with this subject does not begin in a gym. It begins with an MS diagnosis in early 2009.

Like many people with Multiple Sclerosis, one of the most dominant problems for me was fatigue. Not normal tiredness, but the kind of fatigue that quietly hollows out daily life from the inside.

By 2014, I was also severely overweight. I weighed around 160 kilograms. That is not “a bit too heavy.” That is serious obesity, with all the health risks that follow.

The turning point was not vanity. It was fatherhood.

In 2014, my daughter was about two years old. And I had a brutally clear realization: I did not have the energy I wanted in order to be the father I wanted to be.

That was the real driver. Not appearance. Not ego. Not some fantasy about becoming an athlete. Necessity.

I did a deep dive into training options and became fascinated by indoor rowing because it combined high calorie expenditure with low impact. For someone in my situation, that combination mattered.

December 23, 2014: the rowing machine arrived

That date changed my life.

Within roughly six months, I lost about 50 kilograms. Within less than ten months, my weight had dropped from around 160 kilos to around 80. Diet was obviously a major part of that transformation, but physical activity became one of the main engines that drove the whole process.

The biggest reward was not the scale. It was function. It was energy. It was mental clarity. It was getting more of my life back.

Over time, movement stopped being a project and became part of my operating system

At first, the goal was simple: get more energy, more structure and a better chance to function well as a father and a human being.

Over time, something bigger happened. Physical activity stopped being a temporary fix and became one of the deepest pillars in how I regulate energy, protect function, improve clarity and stay psychologically anchored.

As of now, I have rowed every day for 2,075 consecutive days, averaging roughly 10,000 meters per day. That is extreme by normal standards.

But I do not present that as the standard anyone else should chase. I present it as proof of what continuity can build over years.

This is one of my strongest beliefs: all activity counts. Something is always better than nothing. The perfect workout is irrelevant if it never happens. Small actions repeated over time beat occasional heroic efforts.

The real point

Physical activity did not turn me into a superhero. It changed my trajectory.

It helped me lose a dramatic amount of weight. It gave me more energy. It improved day-to-day function. It gave me more mental clarity. It made me more present in my own life. And over time, it became one of the deepest pillars in how I manage life with MS.

That is why this subject matters so much to me. Not because it sounds motivational. Because I have lived the difference.