Episode 105

Muscle, Mitochondria, and Healthspan

Published on: 4th December, 2025

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, resistance training is a powerful pharmaceutical intervention for your metabolic health.


Section 4: Building an Iron Skeleton

However, the benefits don't stop at the muscles. Let's talk about bone density, which is crucial for everyone, especially women. We know calcium and Vitamin D are important, yet they are only one part of the solution.

Remember that bone is living tissue; it responds to stress. When you lift a weight—even if it is just your own body weight in a squat—the mechanical force signals to your bones that they must get stronger. This process is known as the Mechanostat principle. Conversely, without that heavy, high-intensity mechanical load, bone density naturally declines, leading to osteoporosis.

In conclusion, if you only do low-impact cardio, you are helping your heart, but you are not sending the signal needed to maintain or increase bone mineral density. Specifically, you must load your bones to strengthen them.


Section 5: The Importance of Balance and Quality Coaching

Beyond pure strength, true independence depends on mobility and balance. This is where functional training, including Yoga, plays a huge role. My favorite Yoga classes are a combination of bodyweight resistance and cardiovascular movement. I look for the physics—the movement, the resistance, and the balance—and keep the "woo" out of it. Furthermore, a Yoga mat costs far less than some supplements, but it will make a fall much easier to recover from.

Therefore, if you are getting started, please get professional help! Having a great gym coach to help with proper form is paramount—shout out to my friends Jeremy the Hulk and the Zeigler Monster! Additionally, it is equally important to enlist a private Yoga instructor to ensure you are not malaligned and that you know what to look for. A special shout-out to my yogi Xuan—and yes, I will be doing more classes this year!


Section 6: The Ultimate Goal: Getting Back Up

Ultimately, the reason we train is not just to be strong; rather, it is so that if you fall when you are 65, 75, or 80, you possess the strength, stability, and awareness to get up by yourself. This ability is the true mark of functional longevity.

Let me give you two examples of why this ability matters so much. A fellow was admitted to a facility after he broke his hip. Before he fell, he lived alone, was a champion bowler, and enjoyed his life. He simply slipped on a rug, fell, and was found a day later. After his hip was fixed, he spent the next year of his life mostly in bed, eventually dying of COVID-19 in a long-term care facility. One single fall that he couldn't get up from changed his life and his outlook completely.

Contrast that with my own dad. He took a fall at age 96 trying to trim a tree. It took a bit of effort, and he received a stern warning from his son and the EMTs, but he got up. He lived independently until age 98.

Consequently, this kind of preparation matters because the statistics are sobering: falls are the leading cause of injury death for people over 65. Tragically, studies show that up to 30% of seniors who fracture a hip lose their independence entirely.


Conclusion and Call to Action

Finally, resistance training, combined with functional movement, is the macroscopic lever that pulls all those microscopic switches. It is the closest thing to a fountain of youth that doesn’t require a prescription. It just requires effort.

Remember that you must continually increase the demand on your body—this is called progressive overload. Most importantly, remember that resistance training is the stimulus, but protein is the building material. Aim for a high protein intake daily, and definitely enjoy that protein smoothie right after your workout!

On that note, we’re even taking this training on the road this year with our Mediterranean Cruise, where we’ll have an instructor to help you with simple movements—things so that if you fall, you can get up by yourself.


References

  • Dao T, Green AE, Kim YA, Bae SJ, Ha KT, Gariani K, Lee MR, Menzies KJ, Ryu D. Sarcopenia and Muscle Aging: A Brief Overview. Endocrinol Metab (Seoul). 2020 Dec;35(4):716-732. doi: 10.3803/EnM.2020.405. Epub 2020 Dec 23. PMID: 33397034; PMCID: PMC7803599.
  • Sun L, Zhang T, Luo L, Yang Y, Wang C, Luo J. Exercise delays aging: evidence from telomeres and telomerase -a systematic review and meta-analysis of randomized controlled trials. Front Physiol. 2025 Jun 26;16:1627292. doi: 10.3389/fphys.2025.1627292. PMID: 40642293; PMCID: PMC12241061.
  • Massini DA, Nedog FH, de Oliveira TP, Almeida TAF, Santana CAA, Neiva CM, Macedo AG, Castro EA, Espada MC, Santos FJ, Pessôa Filho DM. The Effect of Resistance Training on Bone Mineral Density in Older Adults: A Systematic Review and Meta-Analysis. Healthcare (Basel). 2022 Jun 17;10(6):1129. doi: 10.3390/healthcare10061129. PMID: 35742181; PMCID: PMC9222380.
  • Jeon YK, Jeong J, Shin SD, Song KJ, Kim YJ, Hong KJ, Ro YS, Park JH. The effect of age on in-hospital mortality among elderly people who sustained fall-related traumatic brain injuries at home: A retrospective study of a multicenter emergency department-based injury surveillance database. Injury. 2022 Oct;53(10):3276-3281. doi: 10.1016/j.injury.2022.07.036. Epub 2022 Jul 23. PMID: 35907679.
  • McKendry J, Lowisz CV, Nanthakumar A, MacDonald M, Lim C, Currier BS, Phillips SM. The effects of whey, pea, and collagen protein supplementation beyond the recommended dietary allowance on integrated myofibrillar protein synthetic rates in older males: a randomized controlled trial. Am J Clin Nutr. 2024 Jul;120(1):34-46. doi: 10.1016/j.ajcnut.2024.05.009. Epub 2024 May 16. PMID: 38762187; PMCID: PMC11291473.
Transcript
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>> Dr. Terry Simpson: When my son was three years old, we started him

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skiing. He loved it. When he fell onto his behind,

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onto his butt, he jumped back up and would ski

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down the hill like nothing happened. Pure rubber.

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Now I am 53 years his senior. That same year, his

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mom watched me do an inadvertent 360 degree twirl

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on the slopes. She asked me, if you broke a wrist,

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when could you go back to work? I replied that I

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could probably, uh, have some surgery and go back

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to work if I didn't have a complex fracture in

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about six weeks. The difference between a flexible

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young body and an older body is key here. And yes,

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I retired from skiing that year and now stay in

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the lodge, write and make them great dinners. The

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point is this, your older body needs more work to

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keep flexible, strong and balanced as time goes

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on. I've seen too many independent seniors lose

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their independence after a fall in their own home.

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Sometimes they never recover. They go from living

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on their own to spending their last days in a care

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center, sometimes never leaving bed. And that is

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in health span. You want a fall to be like my

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son's on your butt and back up. But too many fall

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and can't get up. This isn't a commercial for that

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pendant around your neck. This is a plea for you

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to begin doing something with your muscles. We've

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talked a lot about the microscopic world of

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longevity. The tiny powerhouse of the

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mitochondria, the caps on our DNA called

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telomeres, and even those fascinating molecules

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like NAD and urolithin A that keep our cells

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humming. It's all highly technical and it's all

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incredibly important. But today I want to get you

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out of the lab and into the gym. Because there is

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one single accessible and non prescription

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activity that is arguably more potent than any

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supplement on the shelf when it comes to living a

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long healthy life. I'm talking about resistance

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training, lifting heavy things, pushing against

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something that pushes back, not just your

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significant other. It is the single best defense

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we have against frailty, metabolic disease, and

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the inevitable slowing down that comes with the

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decades. And that's exactly what we're going to

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break down today. How, uh, muscle is your

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metabolic savings account, how lifting weights

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changes your bone structure and the absolute best

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way to get started, regardless of your age. I am

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your Chief Medical Explanationist, Dr. Terry

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Simpson, and this is Fork U Fork University, where

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we make sense of the madness, bust a few myths and

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teach you a little bit about food and medicine.

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When we talk about longevity, we focus on

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cardiovascular health. A, uh, strong heart, clear

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Arteries. And that's critical, no doubt. But the

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single greatest threat to functional independence

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as we age isn't heart disease. It's sarcopenia.

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Now, that's a fancy medical term for age related

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muscle loss. After about age 30, we start losing 3

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to 8% of our muscle mass per decade. By the time

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you hit 70, that loss accelerates dramatically.

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This isn't just about looking less toned. It's

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about losing the ability to stand up from a chair,

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to carry groceries, to open a jar, or more

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critically, to catch yourself when you trip. The

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resulting falls are often catastrophic. So where

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does the food and medicine part come in? It's all

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about metabolism. Your muscle is your single

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largest organ for glucose disposal. Think of it

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this way. When you eat, your body releases glucose

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or sugar into your bloodstream. You, your pancreas

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releases insulin to, uh, usher the glucose out of

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the blood and into your cells for energy. The vast

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majority of that glucose is parked in your muscle

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cells. More muscle means better insulin

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sensitivity. It means your body is more efficient

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at regulating sugar. This is the bedrock of

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preventing and managing type 2 diabetes. This is

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why resistance training is not just a gym

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activity. It's a powerful pharmaceutical

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intervention for metabolic health. But here's the

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real kicker and the reason we connect the big,

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heavy dumbbell to the tiny, microscopic cells.

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Small things are benefited by big things. It turns

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out that increasing muscle mass, resistance

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training has a direct positive effect on two of

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the biggest microscopic drivers of aging we've

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discussed. Mitochondrial function and telomere

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health. When you challenge your muscles, you

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signal your cells that they need more energy. This

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stimulates your mitochondria, those cellular

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powerhouses, to become more numerous and to become

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more efficient. Better mitochondrial function

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equals more energy and less oxidative stress. Even

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more fascinating, studies show that resistance

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training actually increases the activity of the

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enzyme telomerase. Telomerase is the same enzyme

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responsible for maintaining those protective caps

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on your DNA, the telomeres, so you don't have to

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take a fancy expensive NAD or telomere boosting

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supplements. Picking up a dumbbell costs less, but

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yields more. You get your muscle strength, the

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better metabolism, stronger bones, and the

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cellular benefits all at once.

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But let's talk about bone density, especially for

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women, but really for everyone. We know calcium

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and vitamin D are important, but they are only a

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part of the equation. Bone is living tissue. It

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responds to stress. When you lift a weight, say a

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heavy kettlebell, or even your own body weight in

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a squat, the mechanical force of that stress

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signals your bones that they need to grow

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stronger. This Process is called the mechanostat

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or the mechanostat principle. Without that heavy,

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high intensity mechanical load, the bone density

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naturally declines, leading to osteopenia and

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osteoporosis. If you're only doing low impact

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cardio like swimming or walking, you're doing

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great things for your heart, but you are not

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sending the signal to maintain or increase bone

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mineral density. To strengthen bone, you have to

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load it. You have to lift heavy enough to make

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your body say, whoa, I need to reinforce the

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structure. But let's do some myth busting here, a

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couple common myths, and let's dive into some

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practical, actionable tips. Myth 1 I'm too old to

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start lifting weights. This is patently false.

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Studies, including those focused on people in

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their 80s and 90s, consistently show that body

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retains the remarkable ability to build muscle and

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increase strength. Even well into advanced age.

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You have nowhere to go but up. I need to work out

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every day. In fact, you absolutely need to do not

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rest is where the magic happens. Two to three

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times a week is often sufficient, provided those

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sessions are challenging enough. Here's a

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practical Focus on compound movements. Don't waste

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your precious time on isolation exercises like

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bicep curls. Focus on compound movements that

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involve multiple joints and multiple large muscle

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groups simultaneously. Think squats, deadlifts,

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overhead presses, rows and lunges. These movements

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mimic daily life and train your body as a unit,

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which is key for fall prevention. Speaking of

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which, comprehensive tips beyond the barbell.

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While pure resistance is key, true independence

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hinges on mobility and balance. This is where

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functional training, including yoga, plays a huge

Speaker:

role. My favorite yoga classes are a combination

Speaker:

of bodyweight resistance and cardiovascular

Speaker:

movement. I look for the physics, the movement,

Speaker:

the resistance and the balance. And I try to keep

Speaker:

the woo of yoga out of it. And a yoga mat isn't

Speaker:

nearly as expensive as some supplement, but it

Speaker:

will make a fall easier to recover from. Now, if

Speaker:

you're getting started, get help. Having a great

Speaker:

gym coach to help with form is paramount. Shout

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out to my friends Jeremy, the Hulk and the Ziggler

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Monster. But it's equally important to enlist a

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private yoga instructor to ensure you are not

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misaligned and that they know what you are looking

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for. Now a shout out to my yoga instructor, Swan.

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And yes, Swan, I'll be doing more classes this

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year. Practical tip number three Master

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progressive overload and protein. Your body adapts

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quickly, so you must continually increase in

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demand. Remember, resistance training is the

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stimulus, but protein is the building material.

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Aim for a protein intake of around 0.5 to 0.7

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grams per pound of body weight per day. And let's

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not forget that smoothie with a protein to

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facilitate things right after the workout. The

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reason we train is not just to be strong. It's so

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that if you fall when you're 65 or 75 or 80, you

Speaker:

have enough strength, stability and awareness to

Speaker:

get yourself back up. That's the true mark of

Speaker:

functional longevity. Now let me give you two

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examples of why this ability matters. A fellow was

Speaker:

admitted to a facility after he broke a hip before

Speaker:

he fell. He lived on his own, was a local champion

Speaker:

bowler and enjoyed life and community. He simply

Speaker:

slipped on a rug and fell and was found a day

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later brought to the hospital and had his hip

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expertly fixed. He spent the next year of his life

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mostly in bed, getting up a few times to try

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rehab, but ultimately died of COVID 19, in a long

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term care facility. One fall that he couldn't get

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up changed his life, his outlook, and sadly, it

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was not a fun year for him. I want to contrast

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that with my own dad. He took a fall at age 96

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trying to trim a tree. Yes, trimming a tree at age

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96. It took a bit of effort and he received a

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stern warning from his son, me, a neighbor and a

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few EMTs who came along when the neighbor saw him

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take the spill. But he got up. Uh, he lived

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independently until age 98, except thankfully, he

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couldn't cook a lick and he stopped driving at age

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96, for which the state of Oregon thank Tim. But

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this kind of preparation matters because the

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statistics are sobering. For people over 65, falls

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are the leading cause of injury death. Breaking a

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hip especially, is a life changing event.

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Tragically, studies show that up to 30% of seniors

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who fracture a hip lose their independence

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entirely and about 20% die within a year. Training

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for strength, balance and fall recovery isn't just

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wellness, it's literally life assurance. It

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literally is healthspan. We're even taking this

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training on the road this year with our

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Mediterranean cruise, which we hope to have in

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August of 2026, where we will have an instructor

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to help you with some simple movements. Not just

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to get big biceps, but things so that if you fall,

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you can get up by yourself. Not this year, but

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maybe in 10 years or 20 years. You want to start

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building muscle now. Resistance training combined

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with functional movement is the macroscopic lever

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that pulls those microscopic switches. It's the

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closest thing to the fountain of youth and it

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doesn't require a prescription, it just requires

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effort.

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Thanks for listening. Please check out my

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blog@yourdoctorsorders.com or forkdue.com for full

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reference to and more information about the topic.

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This was written and researched by me, Dr. Terry

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Simpson. And while I am a board certified

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physician, I am not your physician. Before making

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any changes to your diet, supplements or physical

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activity routine, please check with your board

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certified doctor and registered dietitian. Not a

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chiropractor, some functional holistic salesperson

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of supplements and scams. All things audio were

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done by my friends at Simpler media and the pod

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God, Mr. Mr. Evo. Tara producer girl Productions

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made me more interesting than I really am in real

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life. Have a good week everybody. Hey Evo. I'm

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thinking about those compound movements. What's

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heavier? A squat rack full of plates or the weight

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of a producer's deadline? Yeah, there's so many

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places I thought you were going to take that. Uh,

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uh, I'm happy with that. Right there. Hey man.

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Resistance training for the wind. In fact. Shit.

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I've got about 45 minutes before he gets here.

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Damn.

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About the Podcast

Fork U with Dr. Terry Simpson
Learn more about what you put in your mouth.
Fork U(niversity)
Not everything you put in your mouth is good for you.

There’s a lot of medical information thrown around out there. How are you to know what information you can trust, and what’s just plain old quackery? You can’t rely on your own “google fu”. You can’t count on quality medical advice from Facebook. You need a doctor in your corner.

On each episode of Your Doctor’s Orders, Dr. Terry Simpson will cut through the clutter and noise that always seems to follow the latest medical news. He has the unique perspective of a surgeon who has spent years doing molecular virology research and as a skeptic with academic credentials. He’ll help you develop the critical thinking skills so you can recognize evidence-based medicine, busting myths along the way.

The most common medical myths are often disguised as seemingly harmless “food as medicine”. By offering their own brand of medicine via foods, These hucksters are trying to practice medicine without a license. And though they’ll claim “nutrition is not taught in medical schools”, it turns out that’s a myth too. In fact, there’s an entire medical subspecialty called Culinary Medicine, and Dr. Simpson is certified as a Culinary Medicine Specialist.

Where today's nutritional advice is the realm of hucksters, Dr. Simpson is taking it back to the realm of science.

About your host

Profile picture for Terry Simpson

Terry Simpson

Dr. Terry Simpson received his undergraduate, graduate, and medical degrees from the University of Chicago where he spent several years in the Kovler Viral Oncology laboratories doing genetic engineering. Until he found he liked people more than petri dishes. Dr. Simpson, a weight loss surgeon is an advocate of culinary medicine, he believes teaching people to improve their health through their food and in their kitchen. On the other side of the world, he has been a leading advocate of changing health care to make it more "relationship based," and his efforts awarded his team the Malcolm Baldrige award for healthcare in 2018 and 2011 for the NUKA system of care in Alaska and in 2013 Dr Simpson won the National Indian Health Board Area Impact Award. A frequent contributor to media outlets discussing health related topics and advances in medicine, he is also a proud dad, husband, author, cook, and surgeon “in that order.”