Testosterone affects Muscle Development
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26 September 2009
What is Testosterone?
Testosterone is the principal male sex hormone responsible for the growth and development of male sexual characteristics. This includes genital development in young males, and also the development of what are termed ‘Secondary sexual characteristics’ – like facial hair and the deepening of voice seen at puberty. In adults, testosterone levels also contribute to muscle development, help determine body fat distribution and are vital to sexual activity. Male sex hormones are collectively called ‘androgens’, testosterone is the predominant and most active one. Testosterone is primarily produced in the testes by specialized Leydig cells and circulated throughout the body by blood. Testosterone stimulates cells in the testes to make sperm. It is also a steroid hormone.
Is it produced in women too?
Minute amounts of testosterone are indeed produced in women’s bodies. The primary female sex hormones though are collectively referred to as estrogens. Estradiol is the predominant one. Most are produced in the ovaries. Indeed, in some sort of reciprocity, small amounts of estrogens are even produced in the male testes. Testosterone in women is largely produced in the adrenal cortex and placental tissue. It is thought to play a role in regulating women’s libidos and in bone strength.
Is testosterone used or administered clinically?
Considering its vital role, much research has gone into determining its exact nature and effects over the last sixty years. Its clinical applications – in small, calibrated doses – include treating testicular problems, hypogonadism (where the sex glands produce little or no sex hormones), reduced sexual activity in men and women. Very small amounts are also used in some types of therapy to treat breast cancer. Anabolic steroids, which increase production of testosterone and aid in the development of muscles, are sometimes prescribed to treat the delayed onset of puberty, excessively lean body mass and other such debilitating conditions, and also to treat bone loss in elderly patients. A derivative of testosterone is also being experimented with as a type of chemical contraceptive for men. ‘Hormonal Replacement Therapy’, where depleting levels of the respective sex hormone in the elderly are replaced by synthetic substitutes, is also a contested area of study.
Why is it banned in sports?
The ‘steroids’ most people refer to when discussing athletes and bodybuilders using them to gain unfair advantage are anabolic steroids.These steroids, including testosterone, are banned in virtually every regulated sport. Intake in large doses – orally, by injection or through gel and skin patches – stimulates better protein synthesis in cells and leads to greater muscle mass and dramatic increases in stamina, the reason why many athletes are tempted to use them. The Ben Johnson scandal – where the Canadian athlete was stripped of his 1988 Olympic 100m gold medal, after testing positive for anabolic steroids – is perhaps the most infamous case. Excessive use of anabolic steroids, and the resultant spike in testosterone levels, has been shown to result in serious side–effects.
Does excessive testosterone promote aggression?
This is a hotly contested subject, with much inconclusive data. Some studies have suggested that high levels of testosterone increase competitiveness, risk–taking and dominance behaviour in males, and that testosterone is a biological factor causing aggression. General public opinion also appears to believe in this theory. There is strong evidence that this is the case with animals, but may not be with humans. In fact most researchers and scientists are sceptical about these hormonal correlations and term them simplistic. Most emphasize that hormones do not act in an isolated manner and do not account for any behaviour on their own. Individuals respond to their environments in complex ways, and this may result in increased levels of certain hormones. Behaviour drives hormones, these critics argue, not the other way round. Clearly, a classic chicken and egg dilemma.