In 1950s London, two men climbed aboard the same double-decker bus each morning. One sat behind the wheel. The other walked the aisles collecting fares. Same route, same hours, same socioeconomic backgrounds. Yet one was far more likely to drop dead of a heart attack.

Can you guess who? This was science — the first study of its kind, conducted by a researcher, Jerry Morris, who suspected that how we move might matter more than anyone realized. His findings were unambiguous: the drivers, who rarely moved from their seats, suffered heart disease at dramatically higher rates than the conductors, who spent their shifts on their feet, climbing stairs, threading through passengers and walking casually.

They weren't athletes, these ticket collectors. They were just ... upright! Moving their bodies! Moving in ways the drivers weren't. And that modest difference translated into years of additional lifespan.

I recently spoke with Herman Pontzer, an evolutionary anthropologist at Duke University whose recent book, "Adaptable," explores the often-misunderstood machinery of human physiology. Pontzer has spent years studying the Hadza, a hunter-gatherer tribe in northern Tanzania. What he's learned challenges much of what the wellness industry would have you believe.

For instance, how exercise influences calorie burn. The Hadza walk miles daily, dig for tubers, haul water, hunt game and generally live in ways that would exhaust most hyperjacked Cross-Fitters. Surely these hunter-gatherers burn more energy than a flabby, desk-bound American writer? They don't. Pontzer's careful measurements revealed something remarkable: total daily energy expenditure is roughly the same across radically different lifestyles and cultures. Our bodies, it turns out, are master accountants. Ramp up physical activity, and your metabolism quietly adjusts elsewhere — dampening inflammation, recalibrating hormones, trimming invisible expenditures — to keep the overall energy budget stable.

This is why, as Pontzer puts it, exercise alone is an ineffective weight-loss strategy. Your body simply won't let you outrun your fork. But here's what exercise does accomplish: all those metabolic adjustments — the inflammation tamped down, the hormones rebalanced — are precisely what keep you healthy.

Those bus conductors weren't burning more calories than the drivers. They were burning them differently, in ways that protected their hearts.

For those of us over 50, this reframing matters. Exercise isn't a furnace for incinerating last night's pasta carbonara. It's a maintenance program for a body that, left sedentary, will slowly rust. And the threshold for benefit is encouragingly low. "There's almost no bad exercise out there," Pontzer told me. In other words, any movement, even gardening or carrying groceries from the car trunk to the kitchen counter, makes a difference.

All to say, think about walking around the block more often after a meal. Take the stairs instead of the escalator.

Be the ticket collector, not the driver.

Pontzer's most surprising advice for aging well had nothing to do with dumbbells or diets. "Stay social and stay happy," he said. "That's really going to be the foundation for everything else."

He'd seen it among the Hadza, who live embedded in a tight and interdependent social fabric. Older members of the tribe remain connected, valued and present. And Pontzer noticed something important: when people in modern societies overeat, skip workouts or sink into the couch, the root cause is often psychological, not physical. Because isolation or lack of human interaction can breed personal inertia.

Connection, on the other hand, breeds accountability.

This isn't soft thinking. The epidemiological data on loneliness is as stark as Jerry Morris's bus study. Social isolation correlates with earlier death, cognitive decline and a cascade of chronic diseases. Your gym membership means little if you have no one to talk with about the workout, your sore muscles, your small wins and minor failures.

Pontzer's work also touches on epigenetics — the way our genes are expressed, not just inherited. Remarkably, those switches that turn genes on or off can be influenced by experiences, including those of our parents and grandparents.

Your DNA isn't destiny so much as a keyboard; life decides which keys get pressed. This is humbling and hopeful in equal measure. We are not fixed machines. We are adaptable beings who come pre-loaded, to use a software term, with some genetic influences from our forebears.

The wellness industry would love to sell you a proprietary diet, a patented workout, a supplement stack promising transformation. Pontzer's anthropological view is less glamorous but more honest: walk more, eat reasonably and, for the love of Buddha, call your friends.

To find out more about Paul Von Zielbauer and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

Photo credit: Karthick Gislen at Unsplash