Is your suitcase suddenly heavier, or is it a hidden sign of aging? In this powerful episode of Next Act Ninjas, healthspan expert Rachael Van Pelt reveals why muscle strength is your most crucial—but overlooked—biomarker of healthy aging. Learn why hand-grip strength predicts longevity better than cholesterol, how strength training can reverse age-related decline, and the key to maintaining youthful mitochondria and muscle quality. Whether you're combating midlife fat gain, avoiding muscle wasting and osteoporosis, or simply looking to age with strength and independence, this episode offers practical strategies to build muscle, boost metabolism, enhance cognitive function, and radically improve your quality of life. Anti-aging and lifestyle longevity begins with strength—start today!
Is your suitcase suddenly heavier, or is it a hidden sign of aging? In this powerful episode of Next Act Ninjas, healthspan expert Rachael Van Pelt reveals why muscle strength is your most crucial—but overlooked—biomarker of healthy aging. Learn why hand-grip strength predicts longevity better than cholesterol, how strength training can reverse age-related decline, and the key to maintaining youthful mitochondria and muscle quality. Whether you're combating midlife fat gain, avoiding muscle wasting and osteoporosis, or simply looking to age with strength and independence, this episode offers practical strategies to build muscle, boost metabolism, enhance cognitive function, and radically improve your quality of life. Anti-aging and lifestyle longevity begins with strength—start today!
Chapters
00:00 The Biomarker of Aging We've Been Neglecting
02:22 Grip Strength: The Missing Vital Sign
03:13 Loss of Muscle with Aging
04:52 Muscle Quality vs Quantity
06:39 Mitochondria: The Battery Pack of Youth
08:43 Strength Training Slow Biological Aging at the Genetic Level
09:18 Tracking Strength as a Biomarker of Healthy Aging
11:05 Strong Muscle Translates to Strong Bone
11:29 Strength Train Muscle and Mind
12:10 The Anti-Aging Strengthening Routine
15:03 Start Immediately, Progress Slowly, Track Improvements
17:37 Your 8- to 12-week Age-Reversal Challenge
Hey, hey, welcome back to Next Act Ninjas, the go-to podcast for mastering your health and wealth longevity. I'm your host, Rachael Van Pelt, a retired healthspan scientist turned Realtor and coach. Today I want to talk about the number one biomarker of aging that you're probably taking for granted.
But before I dive in, I'm going to ask you to think about the last time you packed a bag for a trip. Did you go to grab your suitcase and wonder if someone snuck an anvil inside? Once upon a time, that bag used to feel lighter, didn't it? Now you may be noticing it becoming a bit of a struggle just to pull it out of the trunk of your car or to hoist it into that overhead compartment on the plane. I think it's easy to disregard this as a mild frustration that comes with aging. But that subtle loss of strength is actually your biological red flag for age-related decline. In fact, muscle and strength is probably the most important indicator of your health longevity.
For a long time, doctors have obsessed over blood work and vital signs, things like cholesterol, BMI, and blood pressure. But the scientific evidence suggests that muscle strength is at least as important, if not more. In fact, one massive study that analyzed millions of clinic visits found that for every 5kg drop in hand-grip strength, cardiovascular events went up and risk of dying increased by roughly 15%. Remarkably, that simple test of hand-grip strength predicts health outcomes more accurately than cholesterol in many cases. What's even better, it's fast, it's cheap and unlike most lab values, it's something that you can improve in just a few weeks without taking any medication.
And yet hand-grip strength is just the messenger, isn't it? Your quads, your glutes, your back muscles, they all tell the full story. People who maintain the ability to squat, press, and carry heavy loads age more slowly and stay independent far longer than those who try to "save their joints" by avoiding exercise.
Geroscientists now rank age-related loss of muscle, what we call sarcopenia, as the top biomarker of aging. Most anti-aging and biohacking gurus are going to focus on complex biomolecular processes like cellular senescence and telomere attrition, but muscle loss is an even better indicator of aging.
In fact, in a 2024 consensus statement put out by the Global Leadership Initiative on Sarcopenia, declining muscle mass and strength were listed as the clearest physiologic signatures of accelerated aging across every continent studied. So it's reliable across cultures and, even better, an easy thing to measure and track over time.
When we do that, when we track changes with aging, we see that on average, adults lose about 3 to 5% of muscle every decade after age 30. We lose twice that amount after age 55, assuming we're not doing any sort of strength training. And unfortunately, the rate of decline is even worse for women. That's because women start out with about one third less muscle mass than men. So every gram women lose with age is proportionally a bigger slice of their reserve. Even worse, loss of estrogen at menopause accelerates protein breakdown and blunts cell repair. So women really must guard against any muscle loss.
The seriousness of this was highlighted in a Swedish study that followed nearly 3,000 older women for seven years. The women in that study who had sarcopenia were more than twice as likely to suffer falls and fractures compared with their peers who kept their strength. In other words, just a few kilos of lost leg power can mean the difference between continuing to live independently and ending up in a nursing home.
And if you think this is just a problem for your frail elderly grandma, think again. Many people, men and women included, who are overweight and obese suffer from weak muscles. The muscle loss, it's just hidden under a layer of fat. And we call that sarcopenic obesity. And weak grip strength, when it's coupled with excess fat, has been shown to magnify mortality risk far beyond either factor alone. So even if you don't look frail, you aren't in the clear. Only strength tells the whole story.
Moreover, muscle size isn't everything. 30 years ago when I was a young graduate student, we mostly just worried about loss of muscle mass with age. But as we started to use better imaging, like CT and MRI, we looked more closely at aging muscle, and noticed quickly that it wasn't just muscle quantity, but quality that matters. We now know that muscles can look big on the outside and yet be laced with fat and scar tissue and fragmented mitochondria on the inside. This is a phenomenon that we call myosteatosis. That low quality muscle doesn't just make you weak, it worsens your overall health.
In fact, studies in surgical patients have shown that low muscle quality predicts longer hospital stays and more complications that lead to readmission to the hospital after surgery. When you compare low quality muscle with high quality muscle, it's like having two identical sized engines where one is finely tuned and the other is gummed up with sludge. They may weigh the same, but only one engine is going to win the race.
Your muscles work the same way. And that loss of muscle mass and muscle quality doesn't just make you flabby. It shrinks your body's natural "pharmacy". Muscles actually dispense a "cocktail" of protective, age-defying drugs on demand. The stronger and healthier your muscles are, the richer and more diverse your internal "pharmacy". That's why strength training improves your immunity, your wound healing, and it lowers your risk of many age-related diseases. Chronic diseases like diabetes, dementia, osteoporosis, cardiovascular disease, and even premature death.
To get even more granular, when we take our microscope and we zoom down to the level of the muscle cell, we see that the star player is mitochondria. Those are the tiny power plants in your cells that turn oxygen into ATP. They're your body's energy currency. The quality of your muscle depends on how much mitochondria you have and how well it functions. The more efficiently that your mitochondria convert oxygen into ATP energy, the better.
And resistance training improves that efficiency, and it only takes a few workouts. When you exercise, your muscles quickly build new, sleek mitochondria, and they start recycling the old ones. So every challenging set that you complete renovates those battery packs that keep your heart pumping, your brain firing, even your immune system scanning for rogue cancer cells. Sedentary adults are going to see their mitochondrial capacity plummet after age 30. Whereas people in their 70s who keep exercising, their mitochondrial output is almost indistinguishable from people four decades younger.
Without the stimulation of regular exercise, those mitochondria begin to fail. And when they do, they begin to leak what we call ROS, or reactive oxygen species. These ROS are biochemical sparks that nick your DNA, weaken your neuromuscular junctions, and accelerate aging. It's a little bit like having corrosion creep through your car chassis. But luckily, strength training acts like a rust inhibitor. When you demand rapid bursts of energy from your muscles, you're forcing those muscle cells to clear out any defective mitochondria and manufacture new high-efficiency replacements. That cellular housekeeping is called mitophagy. And it's one of the reasons that weight-trained seniors walk faster, think clearer, and recover from illness sooner than their sedentary peers.
Another benefit of strength training is what it does to slow biological aging at the genetic level. Research suggests that strength training can shave years off of life by altering what we call DNA methylation patterns. Moreover, one study showed that combining resistance training with supplements like omega-3 and vitamin D was better than either of those supplements alone for slowing those methylation clocks. This seems to be because that strength training turns youthful genes on while turning the old pro-inflammatory ones off.
Now the good news is we don't have to start taking muscle biopsies and doing MRI scans to gauge your progress. There may be a lot going on at the cellular level, but the science shows that all you really need is a digital hand-grip dynamometer to track strength. Most gyms have one, so all you have to do is ask one of the personal trainers that work there if you can test your grip strength. Or you can find an inexpensive one online. Normal grip strength for a 30-something-year-old woman is around 30 kilograms. For men, it's around 50 kilograms. You want to stay close to that if you want to remain in that biologically youthful range. If you drop below the 20th percentile for your age bracket, it's a red flag. What that means is for a 60-something-year-old man, you're dropping below 30 kilograms. For a woman, dropping below 20 kilograms. If your grip strength drops that low, your risk of age-related disease and mortality increases dramatically.
That said, if you want a more holistic view of your overall strength, don't just stop at measuring grip do some additional strength tests like timing how fast you can get-up-and-go from a chair or how fast you climb stairs and the maximum amount you can lift, pull or press at your typical weightlifting station. I highly recommend tracking those numbers over time so you can see if you're improving or losing ground.
Measure your baseline strength, do some strength training, and then measure strength again. Remember, what gets measured gets managed. If you're only tracking things like cholesterol, BMI, and blood pressure, but you're ignoring strength, you are missing a critical biomarker of healthy aging.
And keep in mind, stronger muscles also translate to stronger bones. The LIFTMOR trials had postmenopausal women with low bone density perform just two 30-minute high-intensity resistance sessions per week. And after just eight months, their strength improved 25%. And bone density improved enough to reverse osteoporosis in many of those women.
What's even more exciting, strength training is good for your brain. Each powerful repetition that you do is sending a bolt of electricity up your sensory nerves. It's lighting up the balance center of your brain and it's firing up those dopamine-rich motivational circuits. So strength training's a little bit like learning a complicated dance. You're stabilizing your core, you're breathing with intention, and coordinating multiple joints. That cognitive demand is probably why people who lift regularly have a 25% lower risk of dementia and depression. Muscle isn't just about building a strong body, it's strengthening your mind.
But I want to shift gears here and look more closely at what a good anti-aging strength training workout actually looks like. Now you want to shoot for three sessions per week, alternating days, especially if you're doing a longer full body workout. you can do six shorter workouts a week where you alternate doing upper body one day, lower body the next. But the key here is to give your muscles a day off between workouts. That gives you time to recover and is actually when strength gains are realized.
For each workout, focus on large compound movements, such as squats or leg presses, deadlifts, rows or pull-ups, overhead presses, that sort of thing. These kinds of large movements recruit more than 80% of your muscle mass and ramp up the hormonal signals that those small muscle movements won't. You want to make sure you're doing a well-rounded strength routine, one that includes both upper body and lower body strengthening. And you're also going to want to mix up the types of sets that you do for optimal gains.
The first type are heavy sets. That's when you do 5-7 reps of heavier weights. It trains your nervous system to fire more motor units and builds your overall strength.
The second type are endurance sets. This is when you do 10 to 12 reps of medium weights. That trains your muscle to last longer, builds more capillaries and mitochondria so that you can turn more of that oxygen into ATP energy more efficiently.
And by the way, this is also what boosts your metabolic rate and prevents fat gain. The more muscle you have and the more oxygen that that muscle uses for energy production, the more calories your body is burning every day. So maintaining metabolism and preventing weight gain is all about maintaining your muscle mass.
The third type of sets are power pulses. These are plyometric exercises like burpees, jumping jacks, jump squats. Quick movements like these keep your fast twitch muscles firing. This is important as we age because we need snappy reflexes to catch ourselves when we stumble. That helps us to avoid falls and fractures.
The fourth type of sets are what we call high-intensity interval training or HIIT workouts. These are short higher intensity exercises like a 4-minute all-out interval on a bike or a rowing machine. Those short HIIT intervals flood your muscles with biochemical messengers that stimulate mitochondrial growth.
The reason we want to incorporate each of those four different types of training sets is so that we're varying the neuromuscular stimulus. So you don't just increase muscle quantity, but also quality. Variety is key if you want to get the most strength gains out of your workouts.
Now, if you're not already doing some kind of strength training routine, I highly recommend starting immediately. But make sure that you progress slowly. Start by doing exercises that just use your body weight. Simple calisthenics like wall sits, push-ups, lunges, and squats, they're great.
If your knees bother you at first, start with static holds. For example, You don't have to jump right into those dynamic lunges. You can do a lunge stance and hold it for as long as you can. Do those static holds for a week or two, and then you can start moving to the more dynamic movements. But whatever you do, don't use your achy joints as an excuse not to exercise. If anything, joint pain is a red flag that your muscles and tendons are weak, and they desperately need strengthening to relieve joint pressure.
Once those weight calisthenics start feeling too easy, that's when you can add some handheld light weights and build up your reps. When you can easily do three sets of 10 to 12 reps, add in heavier weights and do those 5 to 8 rep sets.
You don't have to go to a gym if you don't want. A set of dumbbells is really all you need. Muscles don't care whether tension comes from barbells, kettlebells, or thick resistance bands. Many people will simply start with a light 8 and 10 pound barbell set, for example, and then progress to a 12, 15, and 20 pound set as they get stronger.
Just start with whatever feels safe. The secret sauce though is progressive overload, where you add a little more challenge every week over time. If you stay consistent, your connective tissues are going to get stronger, your nervous system is going to adapt, and what once felt impossible will become your new normal, your warm-up.
Couple that regular routine with 7 to 9 hours of sleep, eat about 1.6 grams of protein per kilogram of body weight every day, and take an omega-3 supplement. All that, you're good to go. Now, you might be asking how much protein is 1.6 grams per kilogram. Well, for someone who weighs about 70 kilograms or 155 pounds, that's about 112 grams of protein per day. 34 grams per meal if you eat three meals a day. You do want to spread it out throughout the day. Make sure you're getting that much into your diet because protein turnover slows as we get older. So we need twice as much protein as when we were younger to build muscle or even just to maintain what muscle we have.
So here's my challenge for you. Stop at your local gym, ask them if they have a hand-grip dynamometer, record your baseline grip strength, and maybe even time how long it takes you to stand up and sit down from a chair five times. Then, commit to the strength training program I just outlined here and retest your grip strength and chair-rise time in about 8 to 12 weeks.
And look, if you know that you won't do this on your own, if you need a coach, someone to make sure that you're doing it right or just doing it at all, you can schedule a call with me and I'll be happy to get you going. You're going to find that link to hop on my calendar in the show notes below. I promise you're going to be amazed at your progress in just 8 to 12 weeks when you're consistent with your training. There's no other pill or procedure that you can do to reverse age-related decline so effectively.
Bottom line, muscle strength is the Rosetta Stone of healthy aging. It is a metric as easy to read as blood pressure, and yet we've neglected it for years. So whether you're hoisting grandkids like kettlebells or you're recovering from being desk-bound for decades, strength is the metric that I want you to measure. It doesn't lie. It tells you exactly how resilient you are today, and more importantly, how well you're going to age into the future.
So start lifting, track your strength gains, and feel those years roll backwards. Until next time, my friends, live well, love more, age less.