Developing and maintaining muscle mass could be the key to living vibrantly and extending healthspan. In this episode, Stuart Phillips, Ph.D., helps us understand why muscle is so important and the best ways to develop healthy muscle. We explore practical tips for resistance training, the role of protein, and questions surrounding protein intake and longevity.
Phillips is an expert in both the science and the practical application of the best tools to improve your muscle mass and improve your health. His expertise will help you learn how to get started building muscle today.
Table of contents:
0:00 Introduction
2:17 Welcome, Prof. Stuart Phillips
7:14 Why is muscle health so important?
14:35 The types of exercise to maximize metabolic health
19:11 The interplay between nutrition and exercise
25:03 More protein content for muscle stimulation?
36:49 Protein from real food vs supplement for health benefit
40:33 The concern with more protein for muscle benefit and longevity
48:08 About Prof. Phillips' upcoming research
50:28 Considerations for animal vs plant protein for muscle health
58:37 Conclusion and where to find Prof. Stuart Phillips
Building and Maintaining Muscle Across the Lifespan: Insights from Professor Stu Phillips
Introduction
Muscle isn’t just the engine powering our movement—it’s one of the pillars of lifelong health, resiliency, and metabolic well-being. Yet for many, the importance of muscle—how to maintain it, how to build it, and how to nourish it—remains underestimated until its absence is felt, often later in life. Recent advances in muscle science, championed by leading researchers such as Professor Stuart Phillips of McMaster University, are transforming how we approach healthspan, exercise, and protein nutrition.Why Muscle Is Essential—At Every Age
Bone health campaigns have successfully educated people about osteoporosis and the necessity of bone strength. As Dr. Phillips explains, muscle deserves equal attention. Sarcopenia—the age-related loss of muscle—may lack a dramatic clinical endpoint like fractures, but its impact is profound. Early, proactive attention to muscle strength can delay or even prevent frailty, loss of independence, and metabolic decline.Dr. Phillips likens muscle to a “reserve” for the human body. In times of stress—illnesses like influenza or COVID-19, or periods of hospitalization—having more muscle provides a vital margin for recovery. The less muscle you have entering these phases, the harder it is to regain independence and function.
When Should We Start Thinking About Muscle?
Most people wait until their 50s or 60s to worry about muscle loss, often writing off declines in strength and mobility as “just aging.” However, research—and Dr. Phillips’ decades of clinical work—shows clearly that investing in muscle health as early as your 20s or 30s pays lifelong dividends. Like building bone density in youth, building and maintaining muscle before older age offers a buffer against the rapid losses that can occur during illness or inactivity.Resistance Training: Breaking Down Barriers
Resistance training remains the cornerstone of muscle health. However, misconceptions abound—especially among older adults who may associate weightlifting with bodybuilding or believe it’s “not for them.” Dr. Phillips emphasizes:- Anybody can benefit: Even people in their 70s and 80s can successfully begin resistance training and improve strength and function.
- It’s about function, not aesthetics: The goal isn’t bulging muscles, but improved quality of life—getting out of chairs, walking confidently, and keeping up daily activities.
- Start simple and safe: Activities that challenge you within 8–13 repetitions, using bands, machines, or bodyweight, all count. Progress, not perfection, is the key.
Cardio vs. Strength: Why You Need Both
The “cardio vs. strength” debate is outdated. Lifelong health and resiliency depend on a foundation of both aerobic fitness and muscular strength. For the average person:- 2+ sessions per week of resistance training (covering major muscle groups)
- 1+ session per week of vigorous aerobic work (challenging your heart and lungs; think stair climbing or hills)
- Daily movement: Walking, cycling, or staying generally active most days.
Protein Intake: How Much, What Type, and When?
1. How Much Protein?
The traditional Recommended Dietary Allowance (RDA) for protein—0.8 grams per kilogram of body weight per day—is simply the minimum to prevent deficiency, not a target for optimal health. Dr. Phillips and current research suggest aiming for roughly double that amount, particularly as you age or if you’re active:1.6 grams per kilogram per day is ideal for most, adjusting lower to ideal body weight for those with high BMI.
2. Protein Distribution & Per Meal Dose
- Spread protein evenly across the day, rather than “saving up” for one big meal.
- The per-meal muscle-building ceiling appears to be about 30 grams (or 0.4–0.5g/kg/meal), but larger meals may still contribute to satiety and other metabolic benefits.
3. Protein Quality: Animal vs. Plant Sources
- Animal-based proteins offer higher quality (in terms of amino acid composition and bioavailability), which becomes increasingly important as we age and our muscles become less responsive to anabolic signals.
- Plant-based diets can provide sufficient protein, but typically require greater attention to total intake, amino acid balance (especially leucine), and portion size.
4. Supplements: Protein Powders As Tools, Not Crutches
- Real food should be the foundation, but protein supplements can fill the gap for those struggling to meet needs, especially in low-calorie diets or for those with limited appetites.
Protein “Risks”: Sorting Fact from Myth
Bones & Kidneys
Despite persistent myths, high-protein diets do not cause kidney damage or osteoporosis in healthy individuals. Extensive clinical studies show no evidence of harm.Longevity & Cancer
Concerns about protein’s impact on longevity—particularly mTOR pathway stimulation and links to cancer—largely derive from animal studies and select observational analyses. Dr. Phillips urges caution in extrapolating these findings to humans, highlighting crucial differences:- Human aging is punctuated by catabolic challenges (infections, hospitalizations) not present in animal models. Muscle reserve (and therefore adequate protein intake) is critical for survival and recovery in these periods.
- Recent—and soon-to-be-published—observational data further question the negative association between higher protein and cancer in humans.
- Any theoretical longevity benefit from reduced protein must be weighed against the proven consequences of sarcopenia, frailty, and poor recovery.
Plant Protein, Leucine, and Methionine
The muscle-building capacity of plant-based proteins is generally lower due to less optimal amino acid profiles—specifically lower leucine, which is key for muscle protein synthesis. This doesn’t mean plant-based eaters can’t thrive, but it requires conscious planning, higher total protein intake, or selective supplementation to reach comparable effects.Concerns about methionine (an amino acid higher in animal protein) from mechanistic aging studies also stem mainly from basic research. While methionine restriction can slow aging in lab animals, the effects and applicability in humans—particularly those facing muscle loss and frequent catabolic stresses—require much more nuanced consideration.
Key Practical Takeaways
- Start resistance training early and never stop. Even novices in their 70s can make real progress.
- Aim for 1.6 grams/kg/day of protein (based on actual or ideal body weight, as appropriate).
- Don’t fear “too much” protein—the real risk lies in too little, especially with age, illness, or periods of inactivity.
- Combine both aerobic and strength exercise for optimal healthspan.
- Prioritize real food proteins, but use supplements pragmatically as needed.
- Adjust protein sources and adequacy if you follow a vegan or vegetarian diet—pay particular attention to leucine and total quantity.
- Ignore myths about kidney and bone risk associated with high protein in the absence of preexisting disease.
- Value muscle as your biological reserve—for mobility, independence, immune function, and recovery throughout life.
Conclusion
Muscle is not just for athletes or the young—it’s a currency for autonomy and health that must be invested in over the long haul. As Professor Phillips concludes, exercise “forgives many sins,” and paired with optimal protein intake, guards against the most feared conditions of aging. Science in this field will continue to evolve, but there’s no downside to building and maintaining strength, function, and muscle mass—starting today.Further Reading & Resources
To follow Professor Stu Phillips and learn more about the science of muscle health, visit him on Twitter (@mackinprof) or LinkedIn.
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How important is muscle health for overall well-being, especially as we age?
Muscle health is incredibly important for overall well-being at all ages, not just for competitive athletes. While it's commonly recognized for locomotion and physical activity, its role extends much further. As we age, maintaining muscle mass becomes crucial for independence, as it directly impacts our ability to perform daily activities like getting out of a chair. Beyond this, muscle acts as a vital "buffer against insult." In situations like infections, injuries, or hospitalizations, the body draws on its muscle reserves. A larger muscle reserve provides a greater capacity for recovery, which is especially critical for older individuals who do not bounce back as easily from periods of disuse or illness as younger people do.When should individuals start thinking about building and maintaining muscle for long-term health?
Individuals should ideally start thinking about building and maintaining muscle in their 20s and 30s. This is analogous to building peak bone mass to prevent osteoporosis later in life. While muscle loss (sarcopenia) might not have a clear "fracture" equivalent as an immediate clinical endpoint, its decline can significantly impact mobility and quality of life later. Proactively maintaining muscle mass early on is a far better investment than attempting to "rescue" it in one's 50s and 60s, which is a much more challenging endeavor.What are common misconceptions about resistance training, and how should someone, regardless of age, approach it?
A common misconception is that resistance training is solely for bodybuilders or involves intense gym sessions. However, resistance training simply means lifting something that feels relatively heavy by the 8th to 12th repetition, indicating that you're challenging your muscles. Even older adults in their 70s and 80s retain the capacity to respond to resistance training. For someone in their 50s or 70s, it's about functional strength – being able to carry groceries, put luggage in an overhead bin, or maintain balance. The goal is not aesthetics but functional capability and resilience against physical insults. Starting resistance training earlier in life makes it easier to maintain as one ages, as it builds a foundation of knowledge and experience.How do strength training and cardiovascular exercise complement each other for optimal health?
While there has historically been a divide between "strength camps" and "cardio camps," for optimal health and longevity, a combination of both is essential. Extremes like bodybuilding or marathon running are not the goal for the average person. Instead, individuals should aim to be both aerobically fit and relatively strong. A practical approach includes at least two days a week dedicated to resistance training (focusing on exercises for legs, pushing, and pulling movements) and at least one day a week of harder aerobic work (like walking up a hill or stairs), supplemented by a couple of other days of general aerobic activity like walking or cycling. The key for resistance training is to hit a high intensity of effort, around an 8 out of 10 on a scale of perceived exertion.What is the recommended protein intake for maintaining muscle and overall health, especially for older adults?
The recommended dietary allowance (RDA) of 0.8 grams of protein per kilogram of body weight per day is simply the minimum to prevent deficiency, not an optimal amount for health and muscle. For older adults, the general recommendation is to consume around 1.6 grams of protein per kilogram of body weight per day. This higher intake supports efficient replacement of damaged proteins and works synergistically with resistance exercise to promote muscle protein synthesis. When calculating protein needs, it's advised to use actual body weight up to a BMI of 30, and then switch to ideal body weight for individuals with a BMI above 30, or lean mass if known.How does exercise influence protein utilization, and can muscle be built in an energy deficit?
Exercise, particularly resistance training, makes muscles more receptive to nutritional delivery, almost like turning them into a "sponge" that craves nutrients. This means that when you are more physically active, your muscles can make greater use of the protein you consume. Interestingly, it is possible to gain muscle even in an energy deficit (while losing fat mass). This concept, once thought impossible, is observed in aesthetic and combative sports athletes and can also be achieved by older individuals, especially when combining higher protein intake with resistance exercise.What are the considerations regarding meal timing and protein intake, particularly for those engaging in time-restricted eating?
While there's a common belief that the body can only absorb about 30 grams of protein per meal, this refers to the amount your muscle can efficiently use, not the total amount you can digest and absorb. Other protein structures in the body also need protein. For individuals eating three meals a day, aiming for an even distribution of protein across meals (e.g., 0.53 grams per kilogram per meal if consuming 1.6 grams/kg/day) is generally recommended for optimal protein synthesis. For those practicing time-restricted eating or intermittent fasting, while it might not be the most optimal way to deliver protein for muscle protein synthesis, the body may adapt over time to upregulate its synthetic capacity for larger meals. However, more research is needed in this area.What is the current scientific consensus on the "dark side" of protein regarding bone health, kidney function, and longevity?
Two persistent myths regarding protein are that it softens bones and causes kidney failure. Scientific evidence unequivocally refutes both. High protein intake does not cause bones to soften, and while individuals with pre-existing kidney disease are often put on low-protein diets to preserve kidney function, protein intake is not the cause of kidney issues in healthy individuals.Regarding longevity, some animal models (flies, mice, rats) suggest that lower protein intake, particularly methionine restriction, might extend lifespan. However, it's crucial to acknowledge that these animal models do not account for critical challenges human beings face, such as periods of catabolic stress (infections, bed rest, hospitalization). In humans, especially as they age, these periods of disuse lead to significant muscle loss. A robust muscle reserve, fueled by adequate protein, is essential to combat this decline, support the immune system, and prevent the transition to frailty. While the science in animal models is valuable, its direct translation to humans, considering the complexities of human life and disease, is not yet definitively settled, and emerging human observational data may challenge some of these assumptions.
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