The Power of Muscles
Muscles do more than just contribute to physical strength; they also play a crucial role in boosting the immune system. When muscles contract, they release certain molecules that help improve immune function. Regular physical activity, which stimulates muscle contraction and growth, has been shown to enhance the body’s ability to fight off infections by promoting a healthy immune response. This dual role underscores the importance of maintaining muscle health not only for physical fitness but also for overall immune system strength.
Muscles increase the immune system
Several studies support the role of muscles not just in physical strength but also in enhancing immune system function:
Muscles and Immune Response Activation: Research using Drosophila and zebrafish models shows that skeletal muscles are immune-responsive tissues. Muscles mount innate immune responses during bacterial infections, an evolutionarily conserved defense mechanism, suggesting that fit muscles could enhance an individual’s innate immune response (Chatterjee et al., 2016).
Skeletal Muscle as a Secretory Organ: Skeletal muscles have been identified as secretory organs that produce and release myokines. These myokines exert autocrine, paracrine, or endocrine effects, influencing various physiological processes including immune function (Pedersen & Febbraio, 2012).
Myokines in Exercise and Metabolism: The discovery of interleukin (IL)-6 release from contracting skeletal muscle has highlighted a potential link between muscle contraction and immune changes. This supports the idea that muscles can communicate with other organs and influence immune system function through the secretion of myokines (Pedersen et al., 2007).
Muscles as an Immunogenic Organ: Skeletal muscle’s capacity to produce several myokines upon contraction, including IL-6, IL-8, and IL-15, indicates its role in immune system regulation. These myokines have immunoregulatory and metabolic roles, further underscoring the muscle’s contribution to immune system strength (Nielsen & Pedersen, 2008).
Exercise-Induced Immune Modulation: Physical activity, which involves muscle contraction, is known to have a profound effect on the immune system. The exercise-induced release of myokines from skeletal muscles suggests a mechanism through which physical activity could modulate immune function (Aurora & Olson, 2014).
These studies illustrate the complex role of skeletal muscles beyond locomotion, including their significant contributions to the body’s immune response through the production and release of myokines.
Muscles counteract the effects of aging
Several studies highlight the importance of maintaining muscle tissue through physical activity and other interventions to counteract the effects of aging:
Physical Activity and Muscle Fat Infiltration: Increased physical activity can prevent the age-associated loss of muscle strength and increase in muscle fat infiltration. Regular physical activity is shown to be effective in preserving muscle function in older adults, suggesting that physically fit muscles might boost the innate immune response of an individual (Goodpaster et al., 2008).
Aging-Related Changes in Skeletal Muscle: Understanding the biological changes induced by physical activity in skeletal muscle is crucial for devising strategies against sarcopenia and muscle aging. There is a consensus that physical exercise is a powerful intervention to obtain long-term benefits on muscle function, reduce the frequency of falls, and maintain independence and high quality of life in older persons (Larsson & Ramamurthy, 2000).
M2a Macrophages and Fibrosis in Aging Muscle: Research indicates that regular physical activity may influence the accumulation of anti-inflammatory M2a macrophages and fibrosis in aging muscle, suggesting that maintaining muscle activity can have beneficial effects on muscle composition and function with age (Wang et al., 2015).
Skeletal Muscle Protein Anabolic Response: The anabolic response of skeletal muscle to resistance exercise and essential amino acids may be delayed with aging, but the combination of resistance exercise and amino acid supplementation is suggested as a strategy to combat sarcopenia (Drummond et al., 2008).
Physical Activity Proteomics of Skeletal Muscle: Being physically active in daily life has been associated with the overrepresentation of proteins linked to mitochondria, TCA cycle, and muscle structure in human skeletal muscle. This suggests that regular physical activity may protect skeletal muscle from aging (Ubaida-Mohien et al., 2019).
Long-term High-level Exercise: High-level recreational activity up to old age has been shown to promote muscle reinnervation and prevent the aging-related loss of skeletal muscle function, indicating that decades of exercise can adapt the body to the aging process and maintain muscle function (Mosole et al., 2014).
These studies collectively suggest that maintaining muscle tissue through regular physical activity and targeted nutritional interventions can significantly mitigate the adverse effects of aging on skeletal muscle function and structure.
Muscles and anti-aging
Several studies have explored substances stored in muscles or affected by muscle activity that have potential anti-aging effects. Here’s a summary of key findings:
Creatine Supplementation: Creatine, synthesized from arginine, glycine, and methionine and found in meat and fish, has been studied beyond its traditional use for athletes. New roles for creatine have emerged in preventing or delaying neurodegenerative diseases associated with aging, such as Parkinson’s and Alzheimer’s diseases. Creatine supplementation has shown promise in treating age-related muscle loss and weakness, known as sarcopenia, by improving muscle function and reducing oxidative damage [Rachel N. Smith, Amruta S. Agharkar, & E. Gonzales (2014)].
Antioxidant Supplementation: Studies have investigated the impact of antioxidants like vitamin E, vitamin A, zinc, selenium, and rutin on muscle and other tissues. While direct improvements in muscle oxidative status were not observed, antioxidant supplementation was found to reduce systemic inflammation/oxidative stress, which might indirectly benefit muscle protein metabolism and combat sarcopenia. Antioxidants showed positive effects in liver, spleen, and heart oxidative status, suggesting their role in a comprehensive approach to aging [L. Mosoni et al. (2010)].
Melatonin: Known for its anti-aging, anti-inflammatory, and antioxidant properties, melatonin’s efficacy in age-related skeletal muscle disorders has been examined. Melatonin supplementation has shown to enhance mitochondrial function, stimulate autophagy, and reduce inflammation in aging muscle, suggesting its potential in limiting skeletal muscle frailty and extending physical performance [A. Stacchiotti, G. Favero, & L. Rodella (2020)].
Nicotinamide Mononucleotide (NMN): NMN, a precursor to NAD+, has been studied for its ability to improve mitochondrial and stem cell function. Supplementation in aging mice has shown to enhance muscle function, suggesting NMN as a promising strategy for improving muscle health and potentially extending lifespan [Hongbo Zhang et al. (2016)].
These findings highlight the potential of various substances, some stored in or influenced by muscle activity, in combating age-related muscle decline and promoting healthy aging. Further research is needed to fully understand their mechanisms and optimize their use in clinical settings.
Physical Activity Increases Cognitive Function
Research has consistently demonstrated that physical fitness can significantly improve cognitive functioning across various domains. Here are some key studies supporting this relationship:
Impact of aerobic exercise on cognitive functions: A study by Stroth et al. (2010) found that increased physical fitness through aerobic exercise improved cognitive flexibility and control in young adults. This study suggests a potential dopaminergic modulation as a mechanism for improved cognitive performance associated with fitness enhancement [Stroth et al., 2010].
Cerebrovascular Reserve and Fitness: Davenport et al. (2012) discussed the positive relationship between physical fitness and cognitive functioning, mediated in part by increases in brain perfusion and the responsiveness of cerebral blood vessels, highlighting a vascular-related mechanism underpinning the fitness-cognition link [Davenport et al., 2012].
Combination of Physical Activity and Brain Training: Shah et al. (2014) demonstrated that a combination of physical activity and computerized cognitive training improved verbal memory and increased cerebral glucose metabolism in elderly participants, suggesting that physical exercise along with mental stimulation can synergistically enhance cognitive functioning [Shah et al., 2014].
Exercise Interventions for Older Adults: Northey et al. (2017) conducted a systematic review and meta-analysis, finding that physical exercise improved cognitive function in adults over 50 years of age, regardless of their cognitive status. This study underscores the broad benefits of exercise on cognitive health across the aging spectrum [Northey et al., 2017].
These studies, among others, provide robust evidence for the beneficial effects of physical fitness on cognitive functions such as memory, executive function, and cognitive flexibility. They highlight various mechanisms, including increased cerebral blood flow, enhanced neuroplasticity, and improved metabolic health, through which exercise promotes cognitive and mental health.
Benefits of Strength Training
Strength training, often associated with building muscle mass and enhancing physical performance, offers a wide array of surprising benefits that extend well beyond the gym. These benefits impact various aspects of health and daily living, including:
Improved Cognitive Function: Engaging in regular strength training has been linked to enhanced cognitive performance. It can improve memory, executive function, and slow cognitive decline, particularly in older adults. This is thought to be due to increased blood flow to the brain during exercise and the growth of new brain cells.
Better Mental Health: Strength training has been shown to reduce symptoms of anxiety, depression, and improve overall mood. This effect is attributed to the release of endorphins during exercise, which are chemicals in the brain that act as natural painkillers and mood elevators.
Enhanced Metabolic Rate: Muscle tissue burns more calories at rest compared to fat tissue. Therefore, increasing muscle mass through strength training can boost your basal metabolic rate (BMR), making it easier to maintain or lose weight.
Improved Sleep Quality: Regular strength training can contribute to better sleep patterns, including falling asleep faster, deeper sleep, and waking up less often throughout the night.
Increased Bone Density: Strength training is effective in increasing bone density and reducing the risk of osteoporosis. By applying stress to the bones, strength training stimulates the bone-forming cells, leading to stronger bones.
Improved Insulin Sensitivity: Muscle contraction during strength training enhances glucose uptake by muscle cells, improving insulin sensitivity. This can help manage blood sugar levels, reducing the risk of type 2 diabetes.
Better Balance and Coordination: Strength training improves muscular strength and endurance, which can enhance balance and coordination. This is particularly important for aging populations, as it can reduce the risk of falls.
Enhanced Cardiovascular Health: While often not the primary focus, strength training can improve cardiovascular health by lowering blood pressure, improving cholesterol levels, and reducing the risk of heart disease.
Improved Joint Flexibility and Health: Contrary to the common belief that strength training might stiffen the body, regular and properly performed strength exercises can actually improve joint flexibility and health.
Increased Lifespan and Quality of Life: By contributing to better overall physical health, strength training can increase lifespan and improve the quality of life by enabling individuals to remain active and independent as they age.
Strength training, therefore, is not only beneficial for athletes or those looking to improve their physical appearance but is also a vital component of a comprehensive health and wellness program for people of all ages and fitness levels.
For an increase in the overall quality of life
Strength training offers a wide range of benefits that extend beyond muscle building and physical strength, impacting various aspects of health and well-being. Here are some key benefits supported by research, with a focus on bone density and overall health:
Improves Bone Health: Strength training is beneficial in increasing bone mineral density (BMD) and reducing the risk of osteoporosis. Regular resistance training has been shown to help maintain and build bone density, offering protection against bone loss associated with aging (Hurley & Roth, 2000).
Enhances Cognitive Function: Exercise, including strength training, has positive effects on cognitive functions, potentially reducing the risk of cognitive decline with aging. It supports brain health by improving memory, executive function, and slowing cognitive decline, particularly in older adults (Cotman, Berchtold, & Christie, 2007).
Improves Metabolic Health: Strength training has been shown to improve insulin sensitivity, reduce blood glucose levels, and enhance the effectiveness of insulin in individuals with type 2 diabetes. It plays a significant role in managing and preventing metabolic diseases (Holten et al., 2004).
Reduces Risk Factors for Cardiovascular Disease: Regular strength training can improve cardiovascular health by reducing resting blood pressure, decreasing low-density lipoprotein (LDL) cholesterol, and improving lipid profiles, contributing to a lower risk of cardiovascular disease (Pollock et al., 2000).
Promotes Weight Management: By increasing lean muscle mass, strength training helps enhance the body’s metabolic rate, making it easier to manage weight. Muscle tissue burns more calories than fat tissue, even at rest (Westcott, 2012).
Improves Mental Health: Engaging in strength training can have positive effects on mental health, including reducing symptoms of anxiety and depression, improving self-esteem, and enhancing overall mood (Seguin & Nelson, 2003).
Supports Functional Independence in Aging: Strength training can significantly improve functional abilities in older adults, such as walking speed, balance, and the ability to perform daily activities, thereby supporting independence and reducing the risk of falls (Seguin & Nelson, 2003).
These studies highlight the multifaceted benefits of strength training, from enhancing bone density and metabolic health to improving cognitive function and cardiovascular health, underscoring its importance as a component of a holistic approach to health and well-being.
Hormonal Balance
Strength training is known to have a significant impact on hormonal balance, including increases in testosterone levels, which can lead to stress relief and various health benefits. Here are some findings from studies that explore these effects:
Hormonal Responses to Strength Training: A study found that strength training can induce changes in serum testosterone and cortisol concentrations, suggesting that the balance between anabolic (muscle-building) and catabolic (muscle-breaking) activities is crucial for strength development. This balance may influence the body’s ability to recover and adapt to training stresses (Häkkinen & Pakarinen, 1993).
Testosterone and Muscle Hypertrophy: Research indicates that strength training can increase testosterone levels, which plays a significant role in muscle hypertrophy (growth) and strength. These hormonal adaptations contribute to the effectiveness of strength training in enhancing muscle size and functional performance (Hansen et al., 2001).
Hormonal Adaptations and Aging: Another study highlighted the importance of testosterone and growth hormone responses to strength training in elderly men. It found that strength training can stimulate increases in these hormones, which are associated with improvements in muscle mass, strength, and potentially stress relief, even in older populations (Häkkinen et al., 2001).
Strength Training and Stress Relief: The physiological stress induced by strength training, reflected in hormonal changes such as increased testosterone levels, can lead to improved stress management and mood. The physical exertion and subsequent hormonal response may help in alleviating symptoms of stress and anxiety, contributing to better mental health and wellbeing.
These studies underscore the multifaceted benefits of strength training, not only in terms of physical health and muscle development but also in hormonal regulation and stress relief. The increase in anabolic hormones like testosterone following strength training sessions supports not only muscle growth and recovery but may also play a role in improving overall mood and resilience to stress.
