Testosterone, Growth Hormones and Muscle Development: An Aggressive Debate

Testosterone is a naturally occurring hormone not only found in humans, but in other mammals, reptiles, and even birds. There is a commonly accepted correlation between fitness and testosterone, but is this commonly accepted correlation in fact true? Or is it possible that there are other growth hormones that play a significant role in the development of the human body? It is also important to note the difference between the male and female human body. The male body is known to carry up to eight times as much testosterone has the female body, which does in fact lead to significant and notable differences. This paper explores whether it is testosterone, other growth hormones, or other external factors that have the greatest effect on growth and muscle development. It is hypothesized that nutrition and exercise are essential supplements to any healthy process of growth and development, but key choices made in the teenage years into mid-20s that effect how testosterone will be released throughout the body during the course of a lifetime. Once the body is well developed into adulthood, it is very difficult to reverse habits and begin practicing and maintaining a healthy lifestyle. This paper attempts to bring insight into which hormone is most responsible for growth and muscle development as well as the specific role of testosterone in that process of muscle development. In order to begin, an analysis of the key hormones in the human body is necessary to isolate the different possibilities.

Testosterone is a naturally occurring hormone found in many animals in existence today. The chemical compound of C19H28O2 is mainly produced and contained in different parts of the metabolism including the liver, prostate and testis. Although found in both male and female, the average male produces about 8 times as much testosterone than the average female. Testosterone production is a predominantly male attribute and plays a significant role in their development. Testosterone is a type of androgen; a class of male sex hormones. Other androgens include dehydroepiandrosterone (DHEA), androstenedione (Andro), androstenediol, androsterone and dihydrotestosterone (DHT). Of these, testosterone is the most commonly found androgen and the most active in the human body. Merriam Webster’s encyclopedia definition of androgens states, “The main and most active androgen is testosterone, produced by cells in the testes” (“Androgen”). Androgens play a key role in the life cycle of a male from prenatal and infancy through puberty and adulthood all the way to the elder stages of life. 

During the prenatal stages of conception, the process of virilization takes place. During virilization, males and females begin to develop distinct biological features. Androgen is the key differentiator between the physical development of a male and a female as its levels are directly responsible for the development of prostate and seminal vesicles. These key identifying male attributes mark the beginning of a complex array of differences between the male and female anatomy. During early infancy and the pre-peripubertal stages of life, androgens remain fairly stable through early muscle and body development. Aside from androgens, it is important to note the importance of vitamin D and calcium intake in the childhood stage. The National Institutes of Health’s publication No. 05-5305A states, “Children and teenagers can get most of their daily calcium from 3 cups of low-fat or fat-free milk (900 mg), but they also need additional servings of calcium-rich foods to get the 1,300 mg of calcium necessary for optimal bone development” (“Building Strong Bones…”). Bone development is important, especially in childhood and puberty, and evidence suggests it plays an important enabling factor for testosterone-enhanced development.

Testosterone and other androgens play an important role in the pubertal stages of the human body. Androgen levels begin to rise and take effect earlier in females than in males, but males have more abundance of the naturally occurring hormones thus the effects are greater. What exactly are these effects? Although there are many notable effects on the human body from the presence of androgens such as hair formation, deepening of the voice and the development of fertility takes place; the most significant effects seem to be in muscle and bone developments. In a study on androgen effects on body composition and muscle function, the division of endocrinology at the Charles R. Drew University of Medicine and Science leadings the study provided evidence of modest increases in fat-free mass, muscle size and strength in groups with replacement and supraphysiological doses in hypogonadal and eugonadal men respectively. Although there are clear effects that come from the increase dosage of testosterone, the study holds that it is inconclusive whether the androgen is directly responsible for the effects (Bross). It appears from the study that there is a discrepancy between the level of androgens introduced and the level of muscle and bone development. There appears to be a correlation between androgens and increases in fat-free mass, the evidence suggests that there is more than testosterone, and androgens in general, that are required for the desired effects on muscle and bone development to take place. 

As it as hypothesized earlier in the paper, critical supplementary factors to the level of androgen presence in the body and muscle development are the levels and quality of exercise and nutrition. Testosterone and other androgens alone cannot be solely responsible for increases in mass and muscle development without any type of physical activity. At least some level of nutrition is guaranteed because every human eats, but physical activity is far from a requirement. In fact, a study conducted by the United States Center for Disease Control and Prevention found, “fewer than two in 10 Americans get the recommended levels of exercise” (Blackburn). This finding is significant because exercise is a significant catalyst to the processing of testosterone in the human body, especially during the stages of pubertal development. An article by Kevin Rail on Livestrong.com, a website dedicated to the life development of the human body founded by Lance Armstrong, discusses the various methods exercises can increase testosterone levels. Based on the various activities listed, such as performing enough sets, lifting weights and incorporating cardiovascular exercises into a workout program, any general activity, whether it be soccer, basketball, wrestling or swimming, is enough of a catalyst to increase testosterone levels. A study conducted by the Department of Human Physiology at the Institute of Exercise and Sport Sciences observed the development of muscle strength in relation to testosterone in young male soccer players. The study concluded “testosterone is important for development of strength in young boys...” (Hansen). There is a relationship between testosterone levels and muscle mass increase, and with the information of exercise boosting testosterone levels in the body, a three-way relationship between exercise, testosterone and muscle mass increases, along with the fourth element of nutrition, making it a four way relationship with exercise, nutrition and testosterone contribute to the development of muscle and bone mass increases. But what exactly is the cause of the increases?

Protein biosynthesis is the process of generating protein by the biological cells that make up the human body. It is an important part in the basic function of life. After all, the body needs energy to operate. In order to power this body, picture it as the coal room on a train. The burning of coal is a chemical process in which energy is released, enabling the train to propel forward. Protein biosynthesis can be compared to this process in that energy in the form of food analogously replaces the coal and the human body analogously replaces the train. The cells use the stored energy in food to perform their functions, which include the growth and maintenance of the human body. It is through the process of protein biosynthesis that the body generates new matter (protein), to new layers to muscles and bones. This is known as muscle and bone development, the topic of study. The process of biosynthesis is what is in fact responsible for muscle growth and development. 

Protein biosynthesis undoubtedly occurs because every human needs to consume food in one way or another. However, there is no necessary requirement for exercise, and as it was clearly evident through the study of the CDC, only 2 in every 10 Americans gets the proper amount of exercise. And as established earlier in the paper, exercise can be used to significantly increase the level of testosterone in the human body. The level of testosterone in the human body has long been correlated with increases in muscle mass and development, but there has been no conclusion of its direct causality. Exercise and testosterone are linked to the process of protein biosynthesis, the process of generating protein in the body. As a person is exercises, the exertion of force coming from the body requires energy in order to propel through such an action. As the body endures rigorous, consistent exercise as described on the Livestrong website, the body expends a significant amount of energy. The body recovers its energy through the consumption of nutrition. However, the consumption of nutrition alone is not sufficient for recovery. This is because the process of protein synthesis needs to take place to generate more protein. The protein is built onto the body in the form of muscles, resulting in the effect this study attempted to connect. What appears is an interconnected web of three factors that result in the following:

During the period of pubertal transition, the choices the adolescent makes are crucial to the levels of testosterone that will be produced in the body during this critical period of development. These seemingly simple decisions, such as deciding the join the football team or wrestling team in high school, are arguably life changing. If the adolescent chooses to engage in some type of physical sport, there is a high probability they will be held to some standard of commitment, consistency and quality of workout by a coach. This could easily result in a period of exercise engagement for three or four years during the pubertal development of the body. As energy is exerted to meet the demands of the sport, nutrition after the activity and the testosterone levels produced from the activity work to rebuild the muscles on the body stronger than they were before. This allows for a balanced fluctuation between testosterone levels, the occurrence of protein biosynthesis and the continuous development of the body. 

In contrast, if an adolescent chooses not to engage in some sort of physical sport, they are likely to spend most of their day in idle movement without any sort of significant physical exertion. As testosterone levels rise during the development stage of puberty, the body has no use for the excess testosterone, as there is no need for excess protein generation through biosynthesis because there was no physical exertion requiring energy. Thus, the body is above the standard levels instead of fluctuating above and below equilibrium as the student performing exercises. These seemingly inconsequential lifestyle choices do in fact have significant implications on how the body is designed and functions during the period of adulthood.

Testosterone levels are important in the maintenance of the health of an aging male. As with strong correlations between testosterone and muscle mass increases, there are also strong correlations between testosterone levels and disease prevention. Some diseases that seem to be correlated with testosterone levels are cardiovascular disease, heart attack, and prostate disease. However, it appears as if there is strong contradiction between different studies. An extensive study conducted by the Division of Endocrinology at Mayo Clinic College of Medicine involving 1642 men studied the effects of testosterone levels on the state of their health. The study concluded that the doses of testosterone received by the patients did not result in any significant changes in blood pressure, glycemia and lipid fractions (Haddad). 

In contrast, another study conducted by faculty at the Gulf Medical University School of Medicine found that there were indeed notable effects that could be reached through the proper administration of testosterone therapy and could be helpful in preventing CHD and other cardiovascular disorders (Jones). In sum, a study co-conducted with the same scholarly author, current evidence on the effects of testosterone on the aging male body and its role in combating diseases is brought to light. The study appears to blend pieces of both of the previous studies. This shows that there are specific case-by-case reactions to the androgen based on the target patient. Some people react to the hormone differently. And what could possibly be the source of different reactions to the hormone? The seemingly inconsequential life choices made in the critical pubertal stages of development. Based on the body’s previous experience with testosterone and muscle development, the body will react accordingly with the introduction of the androgen. If there was no energy exerted through physical exercise, the body is in no need for testosterone to fuel the process of protein biosynthesis. As a result, the testosterone therapy may be less effective for some than others who have bodies capable of processing levels of testosterone to not only grow, but maintain their muscles through aging.

With heart problems being one of the leading causes of death, and the heart in itself being a muscle, it is important to note that there is some level of correlation between testosterone and the maintenance of cardiovascular health (such as treating cardiovascular insufficiency) over a long period of time, otherwise known as adulthood. The precedents set by the body during its childhood and pubertal development stages determine the tolerance and capabilities of a body during its stages of adulthood. Considering the wide variety of different lifestyle choices that exist, there could be an endless variety of reactions to the clinical introduction to testosterone. And, as determined earlier in the study, testosterone cannot be held as the only factor in determining muscle development and maintenance during the various stages of life. Therefore, as it was during the childhood and pubertal development stages of the body, there are most definitely other factors that affect the level of testosterone produced and maintained throughout the body, as well as certain practices that in turn effect how the body processes the level of testosterone.

As is commonly associated with adulthood, the process of procreating with the opposite sex in turn has some effect on the levels of testosterone throughout the male anatomy. As a psychoneuroendocrinological study conducted by the Department of Endocrinology at the University of Pisa, Italy observing the hormonal changes when falling in love, the beginning stages of “falling in love” are correlated with a sharp decrease in testosterone. The sharp decrease in testosterone is matched with a sharp increase in testosterone in the female body. These sudden shocks to the level of testosterone in the body is due to a complex mixture of emotions in which both the male and female attempt to hold back their physiological “sets” in order to match their partner in rhythm and frequency. As couples having claimed recently falling in love and other couples having claimed being in a relationship for years, major differences in the levels of testosterone were evident. It appears through the study that testosterone levels return to normal for the male and female within one to three years in the relationship. As the testosterone levels return to normal, a positive correlation is found between the returning, rising levels of testosterone and the rate of divorce. Men with lower testosterone are more likely to stay in a relationship while men with higher levels of testosterone are more likely to move for a divorce, however is it impossible to prove causality. This further supports the notion that the body sets its precedents during its developmental stages and operates on those precedents throughout the course of adulthood and life. It is tremendously difficult to adjust the body’s physiological preferences, which widely differ from person to person. 

In addition to falling in love’s effect on testosterone levels in the male anatomy, the concept of fatherhood can also have significant effects on the hormone. A study conducted by the Department of Anthropology at Harvard University discusses the lower level of testosterone associated with males that spend significant parts of their day partaking in bonding type activities with their spouse or child than single men who spend their day single and competitive. People who spend their day bonding with a spouse or a child generally exert little to no energy, requiring little to no use for testosterone to fuel the process of biosynthesis. In contrast, the single male constantly in competition is constantly exerting energy to meet the demands of such a rigorous lifestyle. He, therefore, is locked in a cycle of energy exertion, requiring testosterone build-up to fuel the process of protein biosynthesis to refuel his body for another day of even stronger competition. 

As a result, scientists have studied for years the effect of testosterone doses on the human body, unable to find direct causal evidence. This is because there are many more factors at work that, in combination, directly result to the growth, development and maintenance of muscle. With regards to the maintenance of these muscles through adulthood, there are certain intervening factors that can significantly affect how the level of testosterone in the body, thus, how the body functions and continues its development. 

As the body begins to age and nears its final stages of life, muscles around the body begin to deteriorate as the body. Muscles around the body can deteriorate for several reasons. A major cause of muscle deterioration is the lack of using the muscle. Specifically in older men worn out from a lifetime of energy exertion and further development, as they begin to tire and spend their days relaxing and engaged in noncompetitive, testosterone demanding daily tasks, their body no longer uses the muscle, nor is any testosterone being created through exercise to support the maintenance of the muscle. As a result, the muscles start to wither away. Other reasons for muscle atrophy are cancer, AIDS, congestive heart failure and chronic obstructive pulmonary disease. These cardiovascular and physiological disruptions in the body provide an unfit environment for the process of protein biosynthesis to take place. As a result, the body is unable to further develop, or even maintain the level of muscle that it has and the muscles begin to wither away. Seems like a sad ending to life, but surely something can be done to stop it.

The way to prevent the diseases associated with aging is to never stop working. At the same time, it is critically important not to overwork the body. Overworking the body could easily result in a complete abandonment of physical activity and health in general. It is important to constantly exert energy in some form of light exercise with specific guidelines and consistency. If the body continuously exerts energy, it will be able to produce a higher level of testosterone needed for the process of protein biosynthesis to take place. As the body continues to exert energy, these is a continuous demand for testosterone and the body is always fluctuating over the point of equilibrium. As soon as the consistent physical exertion ends, such as getting married, settling down and having kids, the body no longer needs the production of testosterone. The body is then left with a surplus of testosterone it does not need, rendering it above equilibrium. With nothing for the process of protein biosynthesis to rebuild, there is no need for the process to continue at the previously determined pace and the body is thrown out of consistency. This results in the diseases and muscle deterioration seen with aging. The key, consistently work out in some minimal form and the diseases associated with testosterone and aging can at least be significantly slowed down.

In conclusion, it has commonly been assumed that there is a direct link between testosterone levels and muscle development. Knowing there are other hormones that can factor in, it was determined that testosterone is the most active androgen in the human body. The determination of the physical attributes associated with the male and female sexes are due to the levels of these androgens. The average level of testosterone in a male is about eight times greater than that of a female. As a result, there are behavioral and physiological differences. Testosterone, playing such an important role in the childhood and pubertal stages of development in the human body, is very important in managing in order to live and maintain a healthy lifestyle. Without the elements of proper nutrition and exercise, the function of testosterone cannot be successfully performed, as energy exertion is needed to provide a purpose for the process of protein biosynthesis to take place. As the body enters adulthood, it becomes evident that the choices made during the adolescent stages of development lock in a precedent for the body in adulthood. Due to the wide variety of lifestyles, general testosterone studies can lead to a wide variety of different conclusions. Notwithstanding the differences, it is clear that when the body does not exert some form of physical exercise in conjunction with the essence of nutrition, the body is unable to meet the purpose of its functions and begins to shut down, resulting in the diseases and deterioration seen through examples. The final lesson is never stop working out. 

Works Cited

"Androgen." Merriam-Webster. Merriam-Webster, n.d., http://www.merriam-webster.com/dictionary/androgen.

Blackburn, Bradley. "New CDC Report Says Many Americans Get No Exercise." ABC News, 16 Feb. 2011, http://abcnews.go.com/Health/cdc-report-americans-exercise/story?id=12932072.

Bross, R. "Androgen Effects on Body Composition and Muscle Function: Implications for the Use of Androgens as Anabolic Agents in Sarcopenic States." National Center for Biotechnology, vol. 12, no. 3, 1998, pp. 365-378. http://europepmc.org/abstract/MED/10332559

"Building Strong Bones: Calcium Information for Health Care Providers." NICHD Information Resource Center, n.d., http://www.nichd.nih.gov/publications/pubs/Documents/NICHD_MM_HC_FS_rev.pdf.

Haddad, Rudy M. "Testosterone and Cardiovascular Risk in Men: A Systematic Review and Meta-analysis of Randomized Placebo-Controlled Trials." ScienceDirect, n.d., http://www.sciencedirect.com/science/article/pii/S0025619611609646>.

Hansen, L. "American Physiological Society Journal of Applied Physiology." Development of Muscle Strength in Relation to Training Level and Testosterone in Young Male Soccer Players. n.d., http://jap.physiology.org/content/87/3/1141.short.

Jones, Hugh. "The Effects of Testosterone on Risk Factors For, and the Mediators Of, the Atherosclerotic Process." ScienceDirect,  n.d. http://www.sciencedirect.com/science/article/pii/S0021915009003037.