Fork U with Dr. Terry Simpson

Muscle, Mitochondria, and Healthspan

Fork U with Dr. Terry Simpson

Show Notes

Muscle is Medicine: Why Lifting Weights is Your Best Longevity Investment Clearly, your body changes as you age. I learned this lesson years ago when my son was three years old. We started him skiing, and he loved every minute of it. When he fell, he tumbled onto his behind, jumped right back up, and skied down the hill like nothing had happened. He was pure rubber and resilience. However, I was 53 years his senior that year. I did an inadvertent 360-degree twirl on the slopes myself. His mother saw me and immediately asked if I had broken my wrist, wondering when I could return to surgery. The difference between a flexible young body and an older body is critical. Consequently, I retired from skiing that season and now enjoy the lodge, where I write and make them great dinners. Indeed, your older body desperately needs work to stay flexible, strong, and balanced as time goes on. I have seen too many independent seniors lose everything after a simple fall in their own home. They go from living on their own to spending their last days in a care center, sometimes never leaving bed. This outcome is not healthspan. Instead, you want a fall to be like my son’s—just on your butt and back up. Sadly, too many fall and cannot get up. This isn't a commercial for a safety pendant, but a sincere plea for you to start working your muscles.

Section 1: The Enemy is Muscle Loss (Sarcopenia) Specifically, we talk frequently about heart health and clear arteries in longevity. Those things are unquestionably crucial. Nevertheless, the biggest threat to functional independence as we age is a condition called sarcopenia. This is the medical term for age-related muscle loss. Unfortunately, we start losing about 3 to 8 percent of our muscle mass every decade after age 30. That loss accelerates quickly once you hit 70. This problem is not just about looking less toned; fundamentally, it is about losing the ability to stand up from a chair, carry groceries, or, most importantly, catch yourself when you trip. The falls that result are often catastrophic.

Section 2: Big Things Help Small Things—The Cellular Connection Amazingly, resistance training is effective at the microscopic level, too. We have talked extensively about the tiny, complex mechanisms of the cell, but here is the key takeaway: small things benefit from big things. In fact, increasing muscle mass through training has direct, positive effects on two major microscopic drivers of aging: mitochondrial function and telomere health. To elaborate, when you challenge your muscles, you signal your cells to create more energy. This signal forces your mitochondria—the cellular powerhouses—to become both more numerous and more efficient. Better mitochondrial function equals more energy and less cellular stress. Moreover, studies show that resistance training actually increases the activity of the enzyme telomerase in some cells. Telomerase helps maintain the protective caps on your DNA called telomeres. Therefore, you don’t need to buy fancy, expensive supplements like NAD or telomere boosters. Picking up a dumbbell costs less money but yields more results. You gain muscular strength, better metabolism, stronger bones, and the cellular benefits all at once.

Section 3: Muscle is Your Metabolic Powerhouse Let's consider how muscle mass influences your diet. Your muscle is actually your body’s largest organ for glucose disposal. Think of it like this: when you eat, your body releases glucose (sugar) into your bloodstream. Insulin then works to escort that glucose out of your blood and into your cells for energy. The vast majority of that glucose gets parked in your muscle cells. Clearly, if you have more muscle mass, you automatically have a bigger parking lot for that glucose. Consequently, more muscle means your body gains better insulin sensitivity. It becomes more efficient at regulating blood sugar. This effect is the absolute bedrock of preventing and managing Type 2 diabetes. Ultimately, re

More from Fork U with Dr. Terry Simpson

Oct 16, 2026

With all the spices we have access to, it is amazing how bland recipes have become. I have many cookbooks, some from great chefs, television personalities, and friends. What I am always surprised by is how bland the food has become. People seem to think a bit of salt, pepper, maybe onions, and garlic provide the spices one needs. Perhaps it is because some associate spice with heat. Mostly because many have never experimented with some of those great warm spices available. A pinch of coriander, some freshly ground cumin, a little cardamom, or a touch of cinnamon can turn an ordinary dish into something remarkable. And the most astonishing part is that these spices financed voyages around the world, built cities, created fortunes, and caused people to kill one another. Without the spice trade, it is safe to say that the United States, as we know it, would be vastly different from what it is now. The money loaned to the United States, when we were a fledgling country, came from the wealthy spice merchants from what was considered one of the great hyperempires of the world, based in Amsterdam. But before we go to the birth of the United States, let me take you to the meatball.

Oct 8, 2026

Tea: The Drink That Built an Empire—and Helped Break One China had the tea. Britain had the appetite. John Hancock had a business to protect.

Oct 1, 2026

MesoAmerica and Chocolate In our series looking at foods that built civilizations, today we are going to stay in the Americas with chocolate. Chocolate has been used as currency, consumed by kings, incorporated into religious ceremonies, and prescribed as medicine. Today, it is a multibillion-dollar industry that wants you to believe that eating chocolate is an act of preventive cardiology. I mean, why not? They convinced us to give chocolate to people we love, eat it when we are happy, when we are sad, when only the dog understands us. Don’t feed chocolate to your dog. And we have done all this with a bitter seed that most of us would probably spit out if we tasted it straight from the tree.

Sep 24, 2026

I’ve been doing a series about foods that built civilizations. In this episode, we are talking about the potato. It is difficult to imagine that thousands of years ago, people constructed large buildings, managed rivers, built monuments, and created art. We have glimpses of these civilizations through stories, archaeology, and the structures they left behind, but much of their history has been lost. Imagine, we don’t even know where Cleopatra or Alexander the Great are buried, yet we know their stories. As European powers conquered Indigenous peoples, their languages, cultures, and oral traditions were suppressed. When a language disappears, so are the stories preserved within it. Our clues come from archaeology when we uncover a monument, a building, or an ancient settlement. In the Andes, the potatoes they cultivated were not the Russets, Yukon Golds, or fingerlings you find in the store today. Different colors, shapes, and textures. Adapted to survive the elevations, temperatures, and growing conditions. Biodiversity protected their food supply against frost, disease, and changing environmental conditions. If one variety failed, another might survive. The ancient wisdom of diversity that Andean farmers developed over thousands of years was lost when the potato eventually reached Ireland.

Sep 17, 2026

In our series about foods that built civilization, we talked a lot about grains, from wheat to corn to rice. Today, we are taking you to the ocean, with the civilizations that salmon built. From California to the interior of Alaska, salmon, a staple, allowed people to settle into villages, develop complex social networks, art, and trade routes. Those trade routes are as large as the ones in the Mediterranean. Some tribes built communal homes and developed complex art and language. Some were Seafaring tribes with canoes up to 60 feet long that traveled across oceans. All because there was a fish that would return in large numbers to streams and rivers, reliably, predictably. So predictable, the people could build their lives around salmon runs. So much so that some built a calendar not only with lunar cycles, but also with the return of the salmon. Civilizations have always gathered around food and water. The Mediterranean connected people who grew wheat and olives, giving people time to make wine, mine copper, build ships, trade with their neighbors, and occasionally go to war with them. Asia had rice and grain near the great river systems. The reliable calories from rice and grains allowed villages to become cities and to travel by water to trade. Today we are going to my home, from the Ventura River in California to my home state of Alaska.

See all episodes →