In this video, Nick Norwitz reviews a recent study of 139 adults aged 20‑93 that compared the effects of aging versus regular exercise on body composition, muscle function, and mitochondrial health. The key findings are: (1) Physically active seniors (average age 76) have body‑fat and lean‑mass percentages almost identical to inactive young adults (average age 30), and their functional performance is similarly comparable. (2) Even modest weekly activity (≈6 h total, with ~2.5 h resistance training) yields these benefits, but resistance training is under‑represented compared with aerobic exercise, especially in the 40‑69 age groups. (3) Muscle mass is a major predictor of longevity because it acts as an endocrine organ, releasing myokines such as irisin that protect the brain and improve glucose handling. (4) A specific age‑related decline—mitochondrial calcium retention capacity—occurs despite regular exercise, reducing mitochondrial resilience and contributing to muscle weakness. (5) Emerging research suggests oleuropein, a compound from olive leaves, can restore mitochondrial calcium handling and improve muscle mass and endurance in animal models. (6) Professor Guspilot, senior author of the study, emphasizes that physical activity preserves overall mitochondrial bioenergetics but does not prevent the calcium‑handling decline, highlighting it as a novel mechanism of muscle aging and a target for future interventions. The video concludes with practical recommendations: aim for 3‑5 resistance‑training sessions per week (30‑60 min each) focusing on large muscle groups, maintain ~6 h of total weekly activity, and consider nutritional strategies (e.g., oleuropein) to complement training. The overarching message is that aging’s impact on muscles is modifiable through consistent resistance training and emerging nutraceuticals.
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"It's not how old you are, it's how you are old." I can't think of a better quote to encapsulate the results of the brand new study that I want to share with you today. It's a one-of-a-kind study that took 139 adults spanning ages 20 to 93, including active and inactive participants across this broad age spectrum. And it asked the question: What are the relative effects of aging and exercise on body composition and muscle function? The results? Surprisingly uplifting. But there's one big problem with aging in muscles that even exercise can't fix. And another new study just found a way to reverse that problem too. I'm going to break this all down in this video. Now let's get to the results. One of the most fascinating findings was how closely the profile of the oldest active group mirrored that of the youngest inactive group. For specifics, comparing active individuals over age 70, average age of 76 years, with inactive individuals in their 20s and 30s, average age of 30, their body compositions were nearly identical. They were within 0.1%. Body fat of each other, 27.2% versus 27.11%, and within 0.2% lean mass of each other, 69.7% versus 69.9%. It's rather eerie how closely matched the body compositions of an active 76-year-old is compared to an inactive 30-year-old. Functionally as well, more active older individuals were fitter. No surprise, but again, for some tests, it was impressive how closely matched the average active 76-year-old was compared to the average inactive 30-year-old. And I will emphasize and heavily caveat average. We're not talking about ultramarathoners or obsessive gym rats here. For the oldest age group of active individuals, the average total physical activity was 6 hours per week, which isn't too bad, including 3.5 hours of aerobic exercise and 2.5 hours of resistance training per week, in addition to 5,250 steps per day. By comparison, inactive individuals across all age groups exercised only about 30 to 40 minutes per week. However, another important caveat to these data is even in active older adults, the proportion of time spent resistance training or weightlifting was far lower than aerobic activity time, especially in the 40 to 69-year age groups. For example, in active adults ages 60 to 69, aerobic training time per week was 300 minutes. Vs. only 70 minutes per week spent resistance training, including weightlifting. This is a really big deal because the propensity to build and maintain muscle mass does decline with age when not prioritized as part of a healthy lifestyle. Yes, aerobic activity like running, swimming, and biking, they're great, but it's a big disservice to overlook the importance of resistance training and especially weightlifting, especially as you age. Muscle mass is in fact one of the greatest predictors of longevity and healthspan. Muscle isn't just for flexing, it's for longevity. Not only does muscle tissue combat frailty, but muscle is a critical endocrine organ, meaning it secretes hormones into the blood. Hormones like irisin, which protects against neuroinflammation, increases levels of brain-derived neurotrophic factor, which itself is key for the effects of exercise on neurogenesis, the growth of new neurons, and on cognition. And irisin may reduce your risk of cognitive decline and dementia. This is a hormone secreted by active muscle tissue that protects the brain, and indeed having more muscle increases this neuroprotective irisin as well as other muscle-derived hormones broadly classed as myokines, which are muscle hormones, that can signal directly to the brain to improve brain health. So in a nutshell, your muscles literally signal to your brain with hormonal chemicals that protect the brain. Think about that the next time you're doing the squat, which is a butt exercise that's also a brain exercise. Quite literally. Muscles, they're also your biggest sink for blood glucose, helping to maintain healthy blood sugar levels, which has a positive knock-on effect for your blood vessels and brain health. So zooming out, the keep it simple, stupid line here is don't forget resistance training and weightlifting as you age. You're spotting your future self. Don't let them down. There are, of course, many different approaches to resistance training and weightlifting, but generally 3 to 5 times per week for 30 to 60 minutes per session is probably sufficient to optimal for most people. It's important to focus on large muscle groups like the glutes, quads, back, chest, and core. And while I couldn't tell you my favorite exercises personally, How much weight would that actually carry? I'm not even 30. Instead, I want to invite you to tell me in the comments: 1. How old are you? And what is your resistance training or weightlifting plan? Learn from each other in our metabolic health community in the comments. I look forward to seeing what you share. Alright, with that important tangent hammered like a sledge on the tire, let's get back to the data from this paper. Specifically, I want to discuss an area where exercise does not protect your muscle from the ravages of time. And also, what might protect them. Muscles. Muscles depend on calcium. Calcium influx into muscle cells is what triggers a muscle contraction. But, more to the point, calcium influx into mitochondria within muscle cells helps activate energy production to fuel muscles. And the ability of muscle mitochondria to import calcium declines with age, in part due to a decrease in the expression of part of the calcium transporter complex in muscle mitochondria membranes. This decline in the ability of all the muscle's mitochondria to import calcium can contribute to decreased muscle metabolic capacity. In an age-dependent manner that is sadly not prevented or protected against by exercise. However, another new paper, a fascinating paper that I reviewed previously on this channel, also revealed there's a natural compound or a group of natural compounds that can treat this muscle dysfunction. You need to check out that video in full, but Briefly, what they found in that paper was oleuropein, a compound found in olive leaves, holds tremendous potential to offset age-related muscle calcium dysfunctions by increasing the activity of mitochondrial calcium transporters. In fact, at least in animal models, olive leaf extract with oleuropein increased endurance exercise performance and even increased muscle mass, which is pretty incredible, right? Now, getting to my big picture takeaways from this and related research. The key lesson from this study is aging is not an inevitable poison to muscles. Yes, the years do take their toll, that's true. But like a well-maintained car, your meatbag machine, your body, can run well for a million miles if it's well maintained. Aging is inevitable, but how you age is largely within your control. I'll also emphasize consistency is key. Based on these data, you don't need to go crazy. Try to target 6 hours per week of dedicated exercise. In addition to getting daily movements, like trying to get more steps and trying to take the stairs rather than the elevator, I'll admit, some hypocrisy there, but in my defense, I do live on the 37th floor. And do not neglect resistance training and weightlifting. The study here showed a bias towards aerobic activity, but building and maintaining muscles gets harder with age. And the best way to ward off the myocyte grim reaper is to resistance train and weightlift consistently throughout the life course. Strong muscles aren't just for aesthetics—they improve insulin sensitivity, they support metabolic health, and even function as an endocrine, hormone-secreting organ that benefits the entire body, especially the brain. However, exercise alone, it doesn't solve everything. One challenge of aging is a decline in muscle mitochondria's ability to import calcium, which reduces their ability to fuel muscle contractions. But the exciting part is that new and emerging research suggests that natural compounds found in foods like oleuropein from olive leaves could help restore this metabolic dysfunction. New breaking research like this, which I'm going to keep covering on this channel if you subscribe, opens the door to potential interventions that go beyond exercise or synergize with exercise to actively support muscle metabolism at the cellular and subcellular levels. So, smash that subscribe button like it's your last rep, and let's keep lifting knowledge together. Hey look, I'm back and I changed! No, but in all seriousness, I'm just back to tell you that Professor Guspilot, the senior author of this research, has gifted us an exclusive clip just for this video so you can hear from the horse's mouth. I asked him a few questions, Here's what he had to say. I hope you enjoy.
Many thanks, Nick, for featuring our work. I believe that our paper is important for several reasons. The first one, and it's not really a novel finding, but I think our paper strengthened the available literature showing that physical activity is effective at promoting physical function and performance across the human lifespan. I think this is a very important message for the general population, and it showcases that physical activity has beneficial effects even at advanced ages. The second reason why I think our paper is important relates to our finding on mitochondrial bioenergetics. So I'm sure many of your viewers heard about mitochondria, how important they are for cellular energetics, metabolism, and mitochondria are also involved in many other key cellular processes that are essential to our health. So there is this idea in the field that with aging mitochondrial bioenergetics progressively declines, and it's often referred to as a hallmark of aging. And in our cohort of inactive participants, we did see a strong trend for a decrease in mitochondrial oxygen consumption, which was our surrogate to assess mitochondrial energetics in our paper, which is in line with what I just mentioned. However, when we looked at our cohort of active participants, we could not see such a trend. So the way we interpreted the data, or what I think the data means, is that people that stay physically active do not see a decline in their mitochondrial bioenergetics. So physical activity can protect mitochondrial bioenergetics across the human lifespan. So if you care about your mitochondria, which I believe you, you should, then integrating including physical activity into your daily life is essential. So the third reason why I think our paper is important, and this is one of the most novel aspects of the work, is that we, we found that with aging mitochondrial calcium retention capacity progressively declines, and this was not protected by physical activity. So just to be a bit technical here, what it tells us is that mitochondrial resilience to calcium stress decreases with aging. So if faced with a calcium stress, mitochondria from old skeletal muscle are going to be more likely to trigger the opening of the mitochondrial permeability transition pore. So this, this pore, its molecular composition is still debated today, but what we know is that if it opens, it can trigger the activation of signaling pathways known to result in muscle atrophy and weakness. And one of the strength of our study is that we found that mitochondrial calcium retention capacity was correlated in humans with markers of muscle mass, strength, and physical performance. So we believe that this may be an important mechanism, uh, here. And the fact that we saw this occurring in both inactive and active participants was for us very interesting because physical activity has many benefits, but it does not stop aging. So the fact that we saw that in both inactive and active participants, so the cohort of active and inactive participants, is to us suggesting that this may be a primary mechanism driving aging in skeletal muscles. So you asked me to touch on how important muscles are for longevity and healthspan, and I can tell you that this is— there is a lot of data in this field. And where the data is, is the strongest is that there is overwhelming evidence that muscle health is essential for healthy aging. We know that the aging-related loss of muscle mass and function increases your risk of fall fractures, you are more at risk of losing your independence, and it's generally negatively impacting the quality of life of afflicted individuals. There is some data that suggests that muscle health is also linked linked with longevity. So I think thinking about preserving your muscle health as you age is critical. You also asked me what I believe the next research questions are coming from this paper, and I have many here, but I will just highlight two. So the first one is this decline in mitochondrial calcium retention capacity that we saw. Is that something that is restricted to muscle, or is that happening in other tissues and organs? So in other words, is that a mechanism that could also be involved in the aging of other tissues and systems in the organism? The second question, it's kind of obvious with our findings, but it's, can we develop a treatment that could target the mitochondrial calcium handling, the functioning of the mitochondrial permeability transition pore, or the consequences of the opening of this pore to improve muscle mass, strength, and physical performance, and thereby improving the quality of life of older adults. Many thanks again, Nick.
