The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".[78][79] Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.[78] The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.[80] Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.[81][82][83][84][85]
Epidemiological evidence supports a link between testosterone and glucose metabolism. Studies in non-diabetic men have found an inverse correlation of total or free testosterone with glucose and insulin levels (Simon et al 1992; Haffner et al 1994) and studies show lower testosterone levels in patients with the metabolic syndrome (Laaksonen et al 2003; Muller et al 2005; Kupelian et al 2006) or diabetes (Barrett-Connor 1992; Andersson et al 1994; Rhoden et al 2005). A study of patients with type 2 diabetes using measurement of serum free testosterone by the gold standard method of equilibrium dialysis, found a 33% prevalence of biochemical hypogonadism (Dhindsa et al 2004). The Barnsley study demonstrated a high prevalence of clinical and biochemical hypogonadism with 19% having total testosterone levels below 8 nmol/l and a further 25% between 8–12 nmol/l (Kapoor, Aldred et al 2007). There are also a number longitudinal studies linking low serum testosterone levels to the future development of the metabolic syndrome (Laaksonen et al 2004) or type 2 diabetes (Haffner et al 1996; Tibblin et al 1996; Stellato et al 2000; Oh et al 2002; Laaksonen et al 2004), indicating a possible role of hypogonadism in the pathogenesis of type 2 diabetes in men. Alternatively, it has been postulated that obesity may be the common link between low testosterone levels and insulin resistance, diabetes and cardiovascular disease (Phillips et al 2003; Kapoor et al 2005). With regard to this hypothesis, study findings vary as to whether the association of testosterone with diabetes occurs independently of obesity (Haffner et al 1996; Laaksonen et al 2003; Rhoden et al 2005).
Infertility in men and women Infertility or a couple being unable to conceive a child can cause significant stress and unhappiness. There are numerous reasons for both male and female infertility but many ways in which medical assistance can overcome problems that people may face. Everything concerning infertility is discussed and explained here. Read now
Binge drinking on the other hand does impact Testosterone levels – especially on a short term basis. Two studies (22 & 23) show that large acute quantities of alcohol consumption in a short period led to decreases in Testosterone levels by a whooping 20-23% after 24hours! Note however this is drinking to extreme excess! Likewise, chronic alcohol abuse is known to reduce testosterone more notably (as seen in alcoholics).
Puberty occurs when there is an “awakening” of the hypothalamic-pituitary axis. The hypothalamus increases its secretion of gonadotropin releasing hormone (GnRH) which in turn stimulates the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH). This leads to a significant increase in the production of testicular testosterone and the induction of the well-known secondary sex characteristics associated with puberty: growth spurt, increased libido, increased erectile function, acne, increased body hair, increased muscle mass, deepening of the voice, spermatogenesis, gynecomastia (usually transient).
The regular intake of testosterone boosters is known for the high level of safety comparing to the hormone injections and the use of illegal steroids. But still to protect yourself against any possible adverse reactions, you should remember that the supplementation can’t be continuous. The breaks from time to time are required. Such an approach to the use of boosters is healthy and best-working if you aspire to enhance own hormone production without any harm.

Cross-sectional studies conducted at the time of diagnosis of BPH have failed to show consistent differences in testosterone levels between patients and controls. A prospective study also failed to demonstrate a correlation between testosterone and the development of BPH (Gann et al 1995). Clinical trials have shown that testosterone treatment of hypogonadal men does cause growth of the prostate, but only to the size seen in normal men, and also causes a small increase in prostate specific antigen (PSA) within the normal range (Rhoden and Morgentaler 2005). Despite growth of the prostate a number of studies have failed to detect any adverse effects on symptoms of urinary obstruction or physiological measurements such as flow rates and residual volumes (Snyder et al 1999; Kenny et al 2000, 2001). Despite the lack of evidence linking symptoms of BPH to testosterone treatment, it remains important to monitor for any new or deteriorating problems when commencing patients on testosterone treatment, as the small growth of prostate tissue may adversely affect a certain subset of individuals.
Any day that you don’t get 20 minutes of direct sunlight on your skin, you want to supplement with 5,000 IUs of vitamin D3. If you get your blood levels tested and you’re extremely low — below 50 IUs — you typically want to do 5,000 IUs twice a day for three months until you get those numbers up. You can do everything in the world, but if your vitamin D levels aren’t right, your testosterone levels will stay low.

I know the experiment didn’t simply bring me back to my pre-August levels because of the fact that when I learned that the original test I took can sometimes overestimate your T levels, I took a more accurate test around four months after the start of the experiment (I’ve continued the lifestyle changes made during the experiment) and my total T had gone up again to 826.9 ng/dL.


Cardiovascular disease, and its underlying pathological process atherosclerosis, is an important cause of morbidity and mortality in the developed and developing world. Coronary heart disease in particular is the commonest cause of death worldwide (AHA 2002; MacKay and Mensah 2004). As well as increasing with age, this disease is more common in the male versus female population internationally, which has led to interest in the potential role of sex hormones in modulating risk of development of atherosclerosis. Concerns about the potential adverse effects of testosterone treatment on cardiovascular disease have previously contributed to caution in prescribing testosterone to those who have, or who are at risk of, cardiovascular disease. Contrary to fears of the potential adverse effects of testosterone on cardiovascular disease, there are over forty epidemiological studies which have examined the relationship of testosterone levels to the presence or development of coronary heart disease, and none have shown a positive correlation. Many of these studies have found the presence of coronary heart disease to be associated with low testosterone levels (Reviews: Jones, Jones et al 2003; Jones et al 2005).

We all remember the time during our teens where our body underwent majority of its changes that led us into adulthood. As far as testosterone levels go, this period of time is where the production of this hormone peaked. Testosterone levels during these teenage years remain high and consistent, and therefore it is not advisable to use a testosterone boosting supplement during this time. This is because, Natural Testosterone Boosters work by encouraging your body to increase it;s natural levels back to their maximum capacity. If your body is already producing it’s maximum amount of Testosterone, these products will be ineffective for you. You should be prioritising quality, intense training sessions with adequate nutrition, rich in protein and carbohydrates to elicit growth and repair.
I’m afraid I have no super cool “secrets” to share and there are no easy shortcuts to increasing your T. If you were expecting some magical potion or supplement or weird body hack that will instantly and naturally increase your T levels, what follows is bound to disappoint. Despite what some companies or websites might tell you, there’s no single thing that will boost your testosterone naturally for the long term.
There is increasing interest in the group of patients who fail to respond to treatment with PDE-5 inhibitors and have low serum testosterone levels. Evidence from placebo-controlled trials in this group of men shows that testosterone treatment added to PDE-5 inhibitors improves erectile function compared to PDE-5 inhibitors alone (Aversa et al 2003; Shabsigh et al 2004).

“I'm 55 years old and hitting the ball further than I've ever hit, and I'm not getting tired going 18 holes! And when I play softball I'm hitting the ball further. I work for the DWP in LA and it's a very physically demanding job. Andro400 really helps because we work 16 hour days a lot. I was turning down a lot of overtime, but when I started taking Andro400, it got me through the day. I really notice a difference – even my wife did. It really works!”
Everlasting T is the most extreme and most affordable testosterone supplement we've ever come across. By utilizing revolutionary, scientifically-proven all-natural testosterone boosting ingredients, Everlasting T naturally and safely ignites testosterone levels to give you every benefit of healthy testosterone levels. Everlasting T is the perfect testosterone booster to help you add lean muscle mass, increase strength, reduce body fat, enhance sexual performance and increase energy.
Vitamin D is arguably the most important vitamin when it comes to testosterone. A study published in the Journal of Clinical Endocrinology examined the relationship between vitamin D supplementation and testosterone levels in men. The authors found that participants with higher levels of vitamin D had significantly higher levels of free testosterone compared to those with insufficient levels of vitamin D.8 Based on these study results, it appears vitamin D has a strong relationship with testosterone levels.
Michael T. Murray, ND, is widely regarded as one of the leading authorities on natural medicine. He is the author of many books, including the classic Encyclopedia of Nutritional Supplements. His latest book is What the Drug Companies Won’t Tell You and Your Doctor Doesn’t Know. Visit him online at doctormurray.com.   Article Courtesy of Better Nutrition  
Although some men believe that taking testosterone medications may help them feel younger and more vigorous as they age, few rigorous studies have examined testosterone therapy in men who have healthy testosterone levels. And some small studies have revealed mixed results. For example, in one study healthy men who took testosterone medications increased muscle mass but didn't gain strength.
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