For Most of Human History, Nobody Had to Think About Exercise

Your great-grandfather probably never once thought about his step count. He didn't track his heart rate during a workout, follow a progressive overload program, or pay a monthly fee to access a room full of equipment designed to simulate physical labor. He almost certainly didn't need to. His job — whether on a farm, in a factory, in a mine, or on a construction site — handled all of it.

The gym is not an ancient institution. It is a very modern solution to a very modern problem.

When Work Was the Workout

Through the first half of the twentieth century, the majority of American workers were employed in physically demanding occupations. Agriculture, manufacturing, construction, mining, and domestic labor accounted for an enormous share of the workforce. The Bureau of Labor Statistics estimates that in 1900, roughly 40 percent of Americans worked in agriculture alone. Factory work, which expanded massively through the early industrial era, involved standing, lifting, and repetitive physical effort across long shifts.

For these workers, cardiovascular fitness, muscular endurance, and caloric expenditure weren't things you scheduled. They were unavoidable consequences of getting through the day. A coal miner didn't need a gym membership. A woman managing a household before electric appliances — washing clothes by hand, hauling water, cooking from scratch over a wood stove — was engaged in sustained physical labor from morning until night.

The concept of "exercise" as a deliberate, separate activity carved out of a leisure schedule simply didn't map onto this reality. You didn't exercise. You worked. The physical benefit was incidental.

The Problem That Created the Solution

The shift began accelerating after World War II. Returning veterans entered an economy that was rapidly automating and suburbanizing. Office work expanded. Cars replaced walking. Washing machines, dishwashers, and processed food reduced the physical demands of home life. Factory automation steadily eliminated the most labor-intensive roles.

By the 1960s, something new was visible in the public health data: Americans were becoming sedentary in ways that had no real historical precedent. The surgeon general's office and researchers like Dr. Jeremy Morris in the UK were publishing studies linking physical inactivity to heart disease. The body, it turned out, needed the exertion that daily life was no longer providing.

This created a gap — and markets fill gaps.

From the Fringe to the Mainstream

The earliest American gym culture was genuinely niche. In the 1950s and early 60s, weight training was largely associated with bodybuilding subcultures operating on the margins — Venice Beach in California being the most famous hub. Joe Weider's magazines promoted physique competitions to a small but dedicated readership. The general public viewed the whole enterprise with a mixture of curiosity and mild suspicion. Muscle-building for its own sake struck most Americans as vain at best, strange at worst.

Then a few things happened in quick succession.

Kenneth Cooper's 1968 book Aerobics reframed physical fitness as a medical necessity rather than a vanity project, selling millions of copies and introducing running and cardio training to a mainstream audience. The jogging boom of the 1970s — symbolized by figures like Jim Fixx — turned recreational running from an oddity into a cultural phenomenon. By the time the 1980s arrived, fitness had fully entered American popular culture.

The aerobics era was transformative. Jane Fonda's workout videos, first released in 1982, sold over 17 million copies and introduced structured exercise to an enormous audience of women who had never thought of themselves as athletic. Gyms began repositioning from intimidating iron rooms to welcoming, social environments. Nautilus machines replaced free weights as the accessible face of strength training. The health club industry, which barely existed as a mass-market business in 1970, was generating billions in revenue by 1990.

The Industry That Never Stops Growing

Today, the American fitness industry generates roughly $35 billion annually. There are over 41,000 gyms and health clubs in the United States. Peloton, Mirror, and a wave of connected fitness platforms extended the gym into the home during the pandemic and permanently altered the landscape again. Wearable technology — Fitbits, Apple Watches, Garmin devices — turned the tracking of physical activity into a constant, quantified practice for tens of millions of people.

The average American who exercises regularly now monitors metrics that would have been incomprehensible to their grandparents: VO2 max, resting heart rate variability, weekly active minutes, sleep cycle quality. We have never, as a society, been more analytically engaged with our own physical condition.

And yet.

Are We Actually Getting Healthier?

This is the uncomfortable question the data keeps raising. Despite the explosion of gym culture, fitness tracking, wellness apps, and a multi-billion dollar supplement industry, obesity rates in the United States have risen steadily throughout the same period that fitness culture expanded. In 1960, roughly 13 percent of American adults were classified as obese. Today, that figure is over 40 percent.

The reasons are complex and go well beyond exercise — diet, food systems, economic inequality, sleep, and stress all play significant roles. But the parallel trajectories of a booming fitness industry and worsening population health outcomes suggest that deliberate exercise, however valuable, isn't a clean substitute for the incidental activity that was simply baked into everyday life for most of human history.

Your great-grandfather didn't track his steps. He also probably didn't sit in a chair for ten hours straight. The gym solved a problem. It just didn't solve the whole problem.

We built a $35 billion industry around compensating for the way we redesigned our lives. That's either a remarkable feat of adaptation — or a very elaborate way of running in place.