From birth, our muscles and bones experience rapid growth during infancy, followed by another surge at puberty that continues through adolescence. This natural progression occurs without any constraints. However, once adulthood is reached, this growth peaks and soon begins a gradual, steady decline.
Muscle strength, for example, peaks around age 25. After that, the muscular system plateaus before declining by approximately 3 to 5 percent per decade past 30—a condition known as sarcopenia. Similarly, bone density follows a comparable trajectory. After reaching its maximum, bone strength diminishes naturally (a process termed osteopenia), which in many cases can progress to osteoporosis—a condition marked by low bone mass and the deterioration of bone structure.
This gradual decline in our musculoskeletal system profoundly affects our quality of life as we age, even if it does not dramatically shorten our lifespan. To mitigate the risks associated with reduced physical capabilities, many people choose to limit the intensity and duration of their activities, thereby lowering the immediate risk of injury or death. However, while this approach may offer short-term gains, it often results in long-term consequences.
As we grow weaker, our movements slow down, our balance deteriorates, and we increasingly rely on assistive devices to get around. This can lead to a downward spiral, where declining mobility eventually culminates in frailty.
It’s not just that our speed decreases; the entire system of our body slows down. In many ways, by accepting these limitations, we may inadvertently signal to our body that its physical prime is over. Whether this is a built-in aspect of aging or a consequence of our behaviors, the result is the same.
This process is not entirely unavoidable. Even though our bodily systems will eventually weaken and fail, the goal is to delay that process as much as possible. We want to extend our period of vitality and control the terms of our physical decline. Ultimately, our aim is to reach our later years with resilience and gratitude, despite the inevitable challenges that come with aging. So how do we do it?
Strength Training is a Start
Our musculoskeletal system doesn't simply deteriorate with age—it atrophies from disuse, especially when it's not challenged with the intensity it was designed to handle. To stimulate the repair and growth process, our muscles and bones need the stress of an effective training session.
For optimal strength training, four key conditions must be met:
- Intensity - The resistance should be set so that the target muscle reaches fatigue after about 8 to 12 repetitions. If the resistance is too low, it won’t challenge the muscle, and if too high, it increases the risk of injury.
- Duration - Performing 2 to 3 sets per exercise is generally sufficient to fatigue each muscle group properly.
- Volume - Each muscle group should be exercised at least once every 4 to 7 days. Too long a gap may cause muscles to revert to their previous state, while too short a rest may not allow for complete recovery.
- Type - Focusing on larger muscle groups such as the legs, back, chest, and core is most beneficial. These groups drive the production of hormones essential for repair and overall growth.
Additionally, incorporating functional strength training is advantageous, especially for improving performance in specific sports or activities. Integrating these workouts into a broader training regimen is highly recommended to maximize overall benefits.
Benefits Beyond Strength
A properly structured strength training session—with the right intensity, duration, volume, and exercise type - triggers a complex hormonal response that not only aids in muscle repair and growth but also supports overall health. During the post-workout recovery phase, the body releases a host of hormones such as testosterone, human growth hormone (HGH), and cortisol. These hormones work synergistically to promote tissue repair, muscle growth, and bone strength.
Importantly, the increase in cortisol following exercise is a natural, short-term response. This acute spike plays a crucial role in mobilizing energy and initiating the repair process. The body quickly counters this temporary rise by producing molecules that neutralize cortisol’s potentially harmful effects. In contrast, chronic elevation of cortisol—as seen in long-term stress—does not trigger the same beneficial countermeasures and can lead to adverse effects on health.
In addition to these hormones, strength training also boosts levels of insulin and Insulin-like Growth Factor 1 (IGF-1), both of which are vital for bone growth and overall anabolism. These hormones help in maintaining bone density and supporting metabolic health.
Beyond the physical benefits, high-intensity exercise enhances the production of key neurotransmitters, including dopamine, norepinephrine, and serotonin. Often referred to as the "feel-good" hormones, these chemicals not only contribute to improved mood and mental well-being but also play a role in balancing cortisol levels. According to research from Brain Plasticity, these neurotransmitters compete with cortisol at the cellular receptor level, aiding in its regulation and helping to restore resting levels post-exercise.
Thus, the hormonal cascade initiated by strength training extends well beyond building muscle—it supports a range of physiological functions that contribute to improved bone health, metabolic balance, and mental well-being.
Protocols high in volume, moderate to high in intensity, using short rest intervals and stressing a large muscle mass, tend to produce the greatest acute hormonal elevations (e.g. testosterone, GH and the catabolic hormone cortisol) compared with low-volume, high-intensity protocols using long rest intervals (from PubMed).
Read more - Testosterone, Cortisol, and Chronic Inflammation (coming soon)
What About Diet?
Strength training is a powerful tool for enhancing our musculoskeletal system, but it’s only part of the equation. To truly optimize muscle growth, bone strength, and overall recovery, we must provide our bodies with the essential nutrients they need to rebuild and strengthen themselves.
Our bones, for instance, require a steady supply of key minerals such as calcium, phosphorus, and vitamin D to maintain density and integrity. Without these, even the most rigorous workouts can fall short, as the bones cannot remodel and fortify themselves effectively. Similarly, muscles rely heavily on adequate protein intake to repair and build new tissue after exercise. Protein provides the building blocks—amino acids—that are critical for muscle recovery and growth.
In essence, neglecting proper nutrition would be akin to trying to build a house without quality materials. While the topic of nutritional strategies and meal planning is vast and will be explored in an upcoming post, it’s important to understand that a balanced diet is indispensable. A synergistic approach, combining strength training with targeted nutrition, ensures that every workout contributes to a stronger, healthier musculoskeletal system.
Conclusion
We all recognize the importance of exercise, yet it's crucial to understand that not all exercise is created equal. While activities like walking offer an excellent starting point and even running—or better yet, trail running—provides vital cardiovascular benefits, these forms of movement alone are insufficient for long-term health and vitality. To truly sustain our ability to embrace life’s adventures and challenges, building strength is essential.
Strength training enhances our musculoskeletal resilience, ensuring that we remain capable, agile, and ready to take on new experiences. It not only fortifies our muscles and bones but also contributes to overall balance, coordination, and metabolic health. In an active, adventurous life, strength is the foundation that supports our capacity to explore, push our limits, and fully engage with the world around us.
Ultimately, the lifestyle choices we make today—combining cardiovascular activities with targeted strength training—will have profound and lasting effects on our longevity and quality of life. Embracing a balanced exercise regimen is not just beneficial; it’s imperative for anyone seeking a robust, dynamic, and fulfilling life.
Oh, one more thing - we are never too old to start.
Updated 3/8/2025