¶ … Columbia Encyclopedia, testosterone is the principal androgen, or male sex hormone. Although it is a male sex hormone, it is also produced in a small amount in women. Testosterone is necessary in the fetus for the development of male external genitalia. The levels of testosterone increase at the time of puberty; therefore, contributing to the further growth of male genitalia, and for the development and maintenance of male secondary sex characteristics, such as facial hair and voice changes. Effects of Testosterone

Testosterone is the most important male sex hormone as it helps in the production of sperm and helps in the production and maintenance of masculine characteristics such as a deep voice, strong muscles. It also helps to increase libido in order to heighten a man's sexual satisfaction. Without a doubt, it is the hormone that every man wants. Low levels of testosterone can negatively affect a man's sexual drive, mood and health by causing symptoms such as fatigue. About 5 million men in America suffer from low testosterone[footnoteRef:1]. The level of testosterone in the male body changes throughout the day, being at its highest in the morning. [1: The Patient Education 2014]

It is also a significant element in the treatment of various diseases in men. Low levels of testosterone increase the accumulation of fat depots which leads to obesity. High levels of testosterone improve mood, energy, reduce fatigue and may motivate a person to engage in physical activity which is aimed at staying in good shape[footnoteRef:2]. [2: Saad and Aversa et al. 2012, 131]

Over the past thirty years, the significant role testosterone plays in glucose homeostasis and lipid metabolism has become obvious[footnoteRef:3]. Cross-sectional epidemiological studies have reported an association between low testosterone levels and increased risk of type 2 diabetes mellitus. Lower total testosterone predicts a higher incidence of the metabolic syndrome. Metabolic syndrome is a group of factors that occur together and increase the risk for cardiovascular disease and type 2 diabetes. [3: Saad 2009, 901 -- 907]

Low testosterone level is also associated with increased mortality in men. A study was carried out to determine the effect of testosterone on men. In an observation of men with low testosterone levels, testosterone treatment was associated with decreased mortality as compared to no testosterone treatment3. Another study carried out showed that a significant mortality risk was associated with low testosterone. Low testosterone levels were correlated with decreased physical function and increased risk for 6-month mortality[footnoteRef:4]. [4: Hiruntrakul and Nanagara et al. 2010]

Although there are medical supplements aimed at increasing testosterone, it is best to increase testosterone in the body naturally and that is possible through exercise. Compound exercises are the best and fastest way to build muscle and increase strength. Compound exercises comprise of moves that engage multiple muscles and joints at the same time. Compound moves make one's work-out more effective and intense, therefore, helping one to speed up weight loss. Losing weight, as will be discussed further in this paper, is helpful in boosting a body's levels of testosterone. Compound exercises such as shoulder press, rows, bench press, squats, dead-lifts accompanied by using weights are a good way to naturally increase the body's testosterone level.

Deposits of fats encourage the production of estrogen in the body. Estrogens are produced in women and are responsible for sexual and reproductive development. They are the female sex hormones, and it is because of these hormones that women get their characteristics such as breasts and menses. Estrogen is a hormone that restricts the production of testosterone in the male body; this makes the male body more susceptible to putting on excess fat. To increase the levels of testosterone in the body, it is important to lose this excess fat by engaging in cardiovascular exercises such as cycling, running or swimming.

Weight-lifting is also helpful in boosting testosterone as it engages multiple muscles of the body and forty-eight hours after weight-lifting, testosterone levels are at their peak.

Physical activity is known to have a range of effects on the male reproductive function, depending on the intensity and duration of the activity as well as the physical well-being of the individual. It appears that relatively short, intense exercise increase serum testosterone levels[footnoteRef:5]. Keeping in view physical conditions such as sexual dysfunction, longitudinal and cross-sectional studies as well as clinical trials were carried out which showed that physical activity resulted in beneficial outcomes, both physical and mental[footnoteRef:6]. The study concluded that quality of life could be improved, and physical conditions, such...

[5: Cumming and Wheeler et al. 1989, 1 -- 17] [6: Penedo and Dahn 2005, 189 -- 193]
Balanced levels of fitness provide worthy health benefits. From the unfit category, one must aim to move to the fit category by engaging in regular physical exercise. Moderate exercise of about thirty minutes thrice a week can bring about beneficial changes in the body. By moving into the category of healthy and fit people, one will be able to decrease their risk of early death due to cancer and cardiovascular diseases.

However, being over-weight does not necessarily mean low levels of testosterone. Fat that accumulates on the body acts as a sponge which sucks up most of testosterone in the blood, therefore, leading to fatigue, weakness, lethargy, and a decreased libido; this happens when fat accumulates on the belly and abdomen. In case fat accumulates on buttocks and thighs, it does not have the same devastating effect on testosterone levels in the body.

Literature Review

In 1982, an experiment involving 63 men was carried out. The men were told to engage in physical short- and long-term exercise such as running, climbing and endurance field test of cross-country skiing. In addition to other substances, their serum levels of testosterone were determined before, during and after exercise. The study concluded an increase in testosterone in endurance trained subjects[footnoteRef:7]. [7: Schmid and Pusch et al. 1982, 84 -- 9]

Testosterone increases linearly in response to exercise once a specific intensity threshold is reached with peak concentrations usually occurring at the end of exercise5. Even low intensity exercise can result in a significant increase, in levels of testosterone, if the duration of exercise is prolonged enough.An experiment involving 45 men was carried out. Blood samples were taken from the participants once while they were resting and once after recovering from intensive physical activity. The results depicted a higher concentration of testosterone in the exercise recovery blood samples than in the resting blood samples.

Also known as strength training, resistance exercise is performed to increase the strength of muscles and bones as well as improve metabolism. Gaining muscle strength makes the performance of daily activities easier. Also, resistance exercise is a beneficial way of losing weight. Studies to test the effect of physical activity on levels of testosterone include the performance of resistance exercise. An experiment consisting of 9 males was performed who engaged in resistance exercise. Their testosterone concentration before, during and at 0, 5, 15, 30, 60 and 120 minutes after exercise was determined. This study by Kraemer[footnoteRef:8] showed an increased level of testosterone after exercise. [8: Ardis 2007, 148]

Another form of exercise is endurance training which is aimed at increasing the endurance of the body. Sutton et al.[footnoteRef:9] carried out a study on the effects that endurance training has on testosterone levels. The study was performed on highly trained athletes and normal male students. The results showed an increase in testosterone levels of the individuals after twenty minutes of endurance training. [9: Sutton and Coleman et al. 1973, 520]

Another early study by Galbo et al. (1977) consisted of 8 men, and the findings of the study suggested an increase in testosterone proportionate to the intensity of the workout. Study by Tsolakis et al. (2000) in juveniles reported increased levels of total testosterone after a period of resistance training[footnoteRef:10]. The study was performed on 42 pubertal and pre-pubertal boys who engaged in a 2-month resistance training program. Blood samples were collected from the individuals before and at the end of the training period. Findings suggested a greater increase of testosterone levels in pre-pubertal boys than pubertal boys. [10: Ardis 2007, 150]

Between April 2006 and April 2009, a study was carried out in Denmark that consisted of more than twenty participants over the age of 18. The participants were submitted to a weight loss program over a period of 14 weeks. Before and after the weight loss program, blood and semen samples of the individuals were taken. The results showed that weight loss was associated with an increase in total sperm count. Additionally, the weight loss was associated with an increase in testosterone[footnoteRef:11]. Therefore, it can be concluded that physical exercise has a positive effect on the levels of testosterone. [11: HAakonsen and Thulstrup et al. 2011, 24]

Isaacs, author of "Hormonal Balance: How to Lose Weight by Understanding Your Hormones and Metabolism" stated that obesity is a cause of low testosterone in men and exercise can improve testosterone levels by helping one lose weight.

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