As we age, our bodies undergo numerous changes, and one of the most significant is the gradual loss of muscle mass and strength. This process, known as sarcopenia, has a profound impact on our longevity and overall health. In recent years, we've seen a growing body of research highlighting the crucial link between longevity and building muscle, revealing how maintaining and increasing muscle mass can play a vital role in healthy ageing.

We'll explore the science behind muscle building in older adults and its effects on mitochondrial function and body composition. We'll also delve into effective strategies for increasing muscle mass in seniors, including resistance training and other forms of exercise. By understanding the connection between skeletal muscle health and longevity, we can take proactive steps to improve our strength, physical activity levels, and overall quality of life as we age.

Understanding Sarcopenia and Its Impact on Longevity

As we age, our bodies undergo significant changes, and one of the most crucial is the gradual loss of muscle mass and strength. This process, known as sarcopenia, is an age-related, involuntary decline in skeletal muscle mass and strength [1]. It's a condition that affects both sexes equally and typically begins as early as our 40s [2].

The prevalence of sarcopenia increases with age. Studies show that 5-13% of people aged 60 and older are affected, with this figure rising to 11-50% for those 80 and above [3]. These statistics highlight the widespread nature of this condition among older adults.

Consequences of Muscle Loss on Health

he impact of sarcopenia on our health and quality of life is profound. As our muscle mass decreases, we experience a decline in strength and functional capacity. This loss can contribute to a number of adverse health outcomes, including disability, frailty, and loss of independence [1].

One of the most significant consequences of sarcopenia is an increased risk of falls. Several studies have shown that reduced muscle strength significantly elevates the likelihood of falling [3]. This risk is particularly concerning as falls can lead to fractures, hospitalisations, and further complications.

Moreover, sarcopenia is associated with acute and chronic disease states, increased insulin resistance, fatigue, and even mortality [1]. It's worth noting that while sarcopenia may lead to frailty, not all individuals with sarcopenia are frail - in fact, sarcopenia is about twice as common as frailty [3].

Relationship Between Muscle Mass & Lifespan

The connection between muscle mass and longevity is becoming increasingly clear. Research has shown that muscle mass is a far better predictor of health than BMI (body mass index) [4]. In fact, we've found that muscle mass is strongly related to mortality among older adults, in ways that lean body mass is not [5].

Muscle mass is intrinsically linked to various bodily systems, affecting not only mobility and strength but also energy levels, immune system function, and even organ function [4]. It's strongly related to factors like walking speed, grip strength, and fracture risk. Interestingly, in very old adults, muscle mass appears to be more strongly related to the risk of hip fracture than bone density [5].

Multiple studies have examined the association between muscular strength and all-cause mortality, consistently reporting significant mortality reductions with increased levels of muscular strength [6]. This underscores the vital role that maintaining muscle mass plays in healthy ageing and longevity.

The Science Behind Muscle Building in Older Adults

As we delve into the science behind muscle building in older adults, we're confronted with a complex interplay of biological processes. We've discovered that the mechanisms governing muscle growth and maintenance change significantly as we age, presenting unique challenges for seniors looking to maintain or increase their muscle mass.

Anabolic Resistance in Ageing Muscles

One of the key factors we've identified in age-related muscle loss is anabolic resistance. This phenomenon refers to the decreased response of muscle protein synthesis (MPS) to protein ingestion in older adults compared to their younger counterparts [7]. We've observed that there's a roughly 10% reduction in dietary protein digestion and absorption kinetics after protein ingestion in older versus younger individuals [7]. This contributes to the age-related anabolic resistance of MPS, making it more challenging for seniors to build and maintain muscle mass.

Hormonal Factors Affecting Muscle Growth

Hormonal changes play a crucial role in muscle building as we age. We've found that the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis gradually declines during normal ageing [8]. This decline has significant implications for muscle growth, as IGF-1 is a potent anabolic factor that sustains organism and muscle growth [9].

Additionally, we've observed that testosterone levels in men decrease by about 1% annually after age 30, with 40% to 70% of men over 70 likely to have low testosterone levels [8]. This is particularly important as testosterone promotes satellite cell activation, survival, proliferation, and differentiation, which are essential for maintaining adult muscle [8].

Cellular Mechanisms of Muscle Hypertrophy

At the cellular level, we've identified several key mechanisms involved in muscle hypertrophy. The metabolic mechanism for changes in muscle mass is based on the dynamic balance between MPS and muscle protein breakdown (MPB) [10]. When the rate of MPS is less than MPB for an extended period, muscle mass declines.

We've also found that the kinase mTOR plays a crucial role in protein synthesis and degradation. mTOR integrates multiple stimuli from hormones, cytokines, nutrients, and ATP/AMP ratio, and signals to the translation machinery via p70S6K1 and 4EBP1 [9]. Simultaneously, mTOR inhibits protein breakdown by blocking autophagy via ULK1 [9].

Understanding these complex mechanisms provides us with valuable insights into potential interventions for maintaining and building muscle mass in older adults. By addressing anabolic resistance, optimising hormone levels, and targeting specific cellular pathways, we can develop more effective strategies for combating age-related muscle loss and promoting healthy ageing.

Effective Strategies for Increasing Muscle Mass in Seniors

We've discovered that building muscle mass in seniors isn't just about lifting weights; it's a multifaceted approach that combines targeted exercise, proper nutrition, and strategic supplementation. Let's explore these strategies in detail.

Optimal Resistance Training Protocols

To gain muscle strength effectively, we need to implement specific training programmes with carefully selected exercises. Multi-joint exercises, also known as compound exercises, are an essential part of any resistance training programme. They engage multiple joints and work several muscle groups simultaneously, making them extremely effective for building strength throughout the whole body [11].

We recommend incorporating exercises like squats, deadlifts, chest presses, rows, and shoulder presses into your routine. These exercises target major muscle groups and have functional benefits for daily activities. For instance, the squat works multiple muscles, including the quads, glutes, hamstrings, and core, in a very functional way [11].

Nutritional Interventions For Muscle Growth

Proper nutrition is crucial for muscle building in seniors. We've found that many older adults don't get enough protein from their diets. Research shows that increasing protein intake, along with resistance exercise, can help to build and maintain muscle mass [12].

We recommend aiming for 0.55–1.0 grammes of protein per pound of body weight per day (1.2–2.2 grammes per kilogramme) [13]. For a 175-pound (79.3 kg) individual, this translates to 95–175 grammes of protein daily [13]. Good protein sources include lean meats, fatty fish, tofu, eggs, and dairy products [26, 27].

Supplements That Support Muscle Building

While a balanced diet is crucial, certain supplements can support muscle building in seniors. Creatine monohydrate has been shown to increase muscle strength and mass when paired with a proper strength training programme [13]. A 2021 review found that creatine supplementation led to significant increases in muscle mass and strength in adults 50 years and older [13].

Vitamin D supplementation may improve muscle mass and strength in older adults with very low levels [12]. Omega-3 fatty acids may help reduce joint pain related to osteoarthritis, potentially making exercise more comfortable [13].

By combining these strategies – resistance training, proper nutrition, and targeted supplementation – we can effectively increase muscle mass in seniors, promoting strength, independence, and overall health as we age.

Conclusion

The intricate connection between longevity and muscle building has a profound impact on healthy ageing. Maintaining and increasing muscle mass plays a crucial role in supporting overall health, enhancing physical function, and potentially extending lifespan. By understanding the science behind muscle growth in older adults and implementing effective strategies such as resistance training, proper nutrition, and targeted supplementation, we can take proactive steps to combat age-related muscle loss and its associated health risks.

As we continue to explore this vital aspect of healthy ageing, it's clear that a holistic approach to muscle building and maintenance is key. This approach not only has the potential to improve strength and physical activity levels but also to enhance overall quality of life as we age. We can help, contact us at Cre8 Fitness to learn more about personalised strategies for building and maintaining muscle mass. By prioritising muscle health, we're not just adding years to our lives, but life to our years.

References

[1] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4066461/
[2] - https://my.clevelandclinic.org/health/diseases/23167-sarcopenia
[3] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060646/
[4] - https://www.nutritionnews.abbott/healthy-living/ageing-well/losing-muscle-8-ways-it-may-impact-your-health/
[5] - https://www.insidetracker.com/a/articles/dr-william-evanswhy-muscle-mass-is-a-marker-of-longevity
[6] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5772850/
[7] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8131552/
[8] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9533189/
[9] - https://www.nature.com/articles/s41467-020-20123-1
[10] - https://academic.oup.com/nutritionreviews/article/81/4/441/6677259
[11] - https://keepingstrong.co.uk/best-resistance-training-exercises-for-older-adults/
[12] - https://www.consumerlab.com/answers/best-protein-to-gain-and-maintain-muscle/best-protein-for-muscle/
[13] - https://www.transparentlabs.com/blogs/all/best-supplements-for-building-muscle-after-60?srsltid=AfmBOopxW1KfBqjmVyLSfQaD8ZsVGOdgcLkaiHJ0l07V9tknKFyr27RQ