1 Introduction

On the morning of March 14, 2018, the renowned theoretical physicist and author of “A Brief History of Time”, Stephen Hawking, passed away. Known as the “man who defied the odds”, Hawking was diagnosed with Amyotrophic Lateral Sclerosis (ALS) at the age of 21 [1]. Similarly, in 2019, China’s prominent figure, former JD.com Vice President Cai Lei, received a similar diagnosis [2]. Through groundbreaking research and pharmaceutical efforts, Cai Lei adopted an unconventional approach to establish the world’s largest ALS patient research database, fostering numerous clinical trials.

These admirable individuals prompted people to contemplate the significance of muscles in the human body. Muscles play a crucial role not only in appearance but also in the functioning of life itself. The benefits of fitness extend beyond aesthetics to enhancing self-confidence.

People’s enthusiasm for fitness is driven by more than just a desire to look good and be healthy. Observing videos of individuals like Hawking and Cai Lei, both facing the challenges of ALS, deeply underscored the importance of muscles in maintaining normal physiological functions. Whether supporting movement, maintaining posture, or facilitating metabolism, muscles play a pivotal role [3]. This curiosity led me to ponder how muscles grow in the average person, why muscle loss occurs in those who are unwell, how fitness enthusiasts alter their muscles through specific training, and the role of muscles in athletes’ physical prowess and competition. These questions sparked a profound interest in understanding the mechanisms of muscle growth.

To answer these questions, the author has delved into existing scientific literature, academic journals, and studies related to muscle training methods. Also, the author has done observational studies. The author observed individuals in fitness settings, noting their training routines, equipment usage, and performance. All of which has provided valuable insights into real-world practices. The paper finds that muscle training could be achieved through either low-weight high-repetition or high-weight low-repetition methods, each with its pros and cons. This research marked the starting point for my exploration into the mysteries of muscle growth.

2 Training Methods and Impact

Training with low weight and high repetitions, although relatively easy on muscle activation, requires more sets to achieve the corresponding volume. This could exert significant pressure on the joints, increasing the potential risk of injury. Especially for those already experiencing joint discomfort during exercise, frequent high-repetition training may lead to prolonged joint fatigue, limiting their range of motion. Therefore, while this training method significantly improves muscle endurance, its impact on joint health needs careful consideration.

Conversely, training with low repetitions and high weight rapidly activates muscles but carries the risk of substantial joint pressure. Particularly in prolonged training, excessive reliance on high loads may result in muscle fatigue, subsequently affecting overall athletic performance [4]. Therefore, understanding the effects of different weights on joints and fatigue helps formulate more personalized and healthy training plans.

2.1 Muscle Tension

For muscles to grow, individuals need to challenge themselves with more stress than they are used to. This is commonly done by lifting heavier weights gradually. When you add this extra tension to the muscles, it triggers changes in the muscle’s chemistry, promoting the activation of growth factors such as mTOR and satellite cells [5].

Muscular tension plays a big role in how well motor units connect with muscle cells [6]. Additionally, two other factors help explain why some individuals might be stronger but not necessarily have larger muscles. Understanding these factors contributes to unraveling the complexities of muscle growth.

2.2 Muscle Damage

If people have ever felt achy after exercising, that’s because their muscles experienced some damage during the workout. This kind of damage releases molecules that cause inflammation and activates immune cells, making satellite cells spring into action. It is not necessary for people to always feel sore for this process to occur; what matters is that the workout causes some damage to the muscle cells. Usually, any soreness lessens as time goes on [7].

2.3 Metabolic Stress

If people have ever felt a bit of discomfort during exercise or noticed their muscles getting bigger in the gym, they have experienced what scientists call metabolic stress. In the past, when bodybuilders mentioned feeling the “pump” and claimed it made their muscles bigger, some scientists were doubtful. But after digging deeper, it turns out there might be something to it.

Metabolic stress leads to the swelling of cells around the muscles, contributing to muscle growth without necessarily making the muscle cells themselves bigger. This happens because of the addition of muscle glycogen, which helps swell the muscles and encourages the growth of connective tissues. This particular type of growth is known as sarcoplasmic hypertrophy, and it’s a way people can make their muscles look larger without necessarily gaining more strength. Understanding these effects of metabolic stress adds another layer to how we perceive muscle growth during exercise.

3 Recent Research Findings

While conventional advice indicates that the optimal range is 6-12 repetitions [8], recent research indicates that achieving muscle failure, even with high-repetition sets and low weights, can be effective [9]. However, in practical training, this range has proven to be the most effective in accumulating volume. Particularly when approaching muscle fatigue, selecting the 6-12 repetition range comprehensively activates muscle fibers, promoting muscle growth. Studies indicate that even in high-repetition training exceeding 12 repetitions [10], as long as it maintains proximity to muscle fatigue, similar growth effects can be achieved.

4 Optimal Repetition Range

4.1 Balanced Training Approach

The observed trend underscores the significance of adopting a balanced approach in training, particularly within the 6-12 repetition range. This optimal range not only ensures the effective activation of muscles but also mitigates stress on the joints. The emphasis on moderate load strikes a harmonious balance, enhancing muscle engagement while safeguarding joint well-being. Enthusiasts seeking comprehensive fitness benefits are encouraged to consider this balanced training method, fostering muscle diversity and overall physical health.

Furthermore, the incorporation of recent research findings into training plans is pivotal for informed decision-making. Selecting the 6-12 repetition range aligns with the current understanding of muscle growth mechanisms, emphasizing the importance of tension, damage, and metabolic stress. By integrating these insights, individuals can tailor their workouts to maximize the benefits of each repetition, supporting not only muscle development but also overall well-being.

In summary, the evolving insights from recent research affirm the 6-12 repetition range as a cornerstone for balanced and effective training. This approach, harnessing the advantages of moderate load and informed by contemporary research, stands as a reliable guide for enthusiasts striving for comprehensive muscle growth and enduring physical health.

4.2 Recommended Training Allocation

When thinking about how different weights affect trainers’ joints and make them tired, it is a good idea to spend most of their training time (around 60%-70%) doing exercises where they repeat movements 6-12 times. This range helps their muscles get bigger, and it is easier to control how much exercise trainers are doing. For the rest of their workouts, it’s a good approach to mix things up by doing some exercises with more reps and some with fewer reps. This way, trainers can get a full package of benefits for their muscles.

It’s like giving trainers’ muscles a balanced diet. So, focusing on 6-12 repetitions helps their muscles grow without causing too much stress on their joints. By adding some exercises with different repetition ranges, makes sure their muscles are getting all-around strong. This mix-and-match strategy considers what trainers’ muscles need, making their workouts effective and flexible.

4.3 Insights from Muscle research

New studies illustrate that instead of sticking strictly to certain exercise repetitions, it is better to focus on getting close to feeling tired during workouts. This new way of thinking gives people more freedom to adjust their exercise plans based on their fit and any health issues they might have. So, with this fresh perspective on muscle growth, combining 6-12 repetitions with some high and low repetitions seems to be a smart way to go. It’s like creating a flexible workout plan that can help muscles grow well and keep the body healthy in the long run.

This flexible approach means trainers can adapt their exercises to what their body needs. It’s like making a workout plan that suits trainers best, considering their strengths and limits. So, by mixing up their repetitions in a thoughtful way, they are not only helping trainers’ muscles grow but also taking care of trainers’ overall health. This simple yet effective strategy gives trainers a balanced and sustainable path toward being stronger and healthier.

5 Conclusion

In conclusion, this research offers insights into the mechanisms of muscle growth, spanning various fields from theoretical physics to practical applications. Understanding these mechanisms not only has implications for physical appearance but also contributes to an overall improved quality of life. By exploring different training methods, we gain a better understanding of how muscles respond, providing practical applications for individuals seeking comprehensive muscle development. The key takeaway from this study is the reconsideration of the conventional wisdom surrounding the optimal repetition range for muscle growth. The research suggests that, even with high repetitions, similar growth effects can be achieved when maintaining proximity to muscle fatigue. This finding has practical implications for designing effective and balanced training routines.

While the research provides valuable insights, it is essential to acknowledge certain limitations. Further exploration is needed to understand individual variations, the influence of health conditions, and the long-term effects of different training methods. Additionally, the impact of genetic factors on muscle growth remains an area for deeper investigation.

Looking ahead, future research could focus on refining personalized training plans, considering individual differences and health conditions. A deeper exploration of the intersection between genetic factors and muscle growth could enhance our holistic understanding of this subject. The journey to harnessing the full potential of muscles continues, promising both aesthetic benefits and improved physical well-being for individuals.