Several studies accessed the prevalence of ED. The Massachusetts Male Aging Study reported a prevalence of 52%.2 The study demonstrated that ED is increasingly prevalent with age: approximately 40% of men are affected at age 40 and nearly 70% of men are affected at age 70. The prevalence of complete ED increased from 5% at age 40 to 15% at age 70.2 Age was the variable most strongly associated with ED.
Attention, memory, and spatial ability are key cognitive functions affected by testosterone in humans. Preliminary evidence suggests that low testosterone levels may be a risk factor for cognitive decline and possibly for dementia of the Alzheimer's type,[100][101][102][103] a key argument in life extension medicine for the use of testosterone in anti-aging therapies. Much of the literature, however, suggests a curvilinear or even quadratic relationship between spatial performance and circulating testosterone,[104] where both hypo- and hypersecretion (deficient- and excessive-secretion) of circulating androgens have negative effects on cognition.
Vacuum devices for ED, also called pumps, offer an alternative to medication. The penis is placed inside a cylinder. A pump draws air out of the cylinder, creating a partial vacuum around the penis. This causes it to fill with blood, leading to an erection. An elastic band worn around the base of the penis maintains the erection during intercourse.
If you’re experiencing psychological ED, you may benefit from talk therapy. Therapy can help you manage your mental health. You’ll likely work with your therapist over several sessions, and your therapist will address things like major stress or anxiety factors, feelings around sex, or subconscious conflicts that could be affecting your sexual well-being.
The symptoms of erectile dysfunction include difficulty achieving an erection, trouble maintaining an erection, and a reduced interest in sex. Because male sexual arousal is a fairly complex process, it can sometimes be difficult to identify a specific cause. Arousal starts in the brain but it also involves the nerves, muscles, and blood vessels and can be impacted by hormones and emotions. If a problem develops with any of these things, erectile dysfunction could be the consequence.
Several treatments were promoted in the pre-PGE1, pre-prostaglandin era, including yohimbine, trazodone, testosterone, and various herbal remedies. None of these is currently recommended under the updated American Urological Association Guidelines for the Treatment of Erectile Dysfunction.15 Testosterone supplementation is only recommended for men with low testosterone levels.
Think of erectile dysfunction as your body’s “check engine light.” The blood vessels in the penis are smaller than other parts of the body, so underlying conditions like blocked arteries, heart disease, or high blood pressure usually show up as ED before something more serious like a heart attack or stroke. ED is your body’s way of saying, “Something is wrong.” And the list of things that cause erectile dysfunction can include:
It is common for a healthy older man to still want sex and be able to have sex within appropriate limitations. Understanding what is normal in older age is important to avoid frustration and concern. Older men and their partners often value being able to continue sexual activity and there is no age where the man is ‘too old’ to think about getting help with his erection or other sexual problems.

ED can also occur among younger men. A 2013 study found that one in four men seeking their first treatment for ED were under the age of 40. The researchers found a stronger correlation between smoking and illicit drug use and ED in men under 40 than among older men. That suggests that lifestyle choices may be a main contributing factor for ED in younger men.
Before assessing the evidence of testosterone’s action in the aging male it is important to note certain methodological considerations which are common to the interpretation of any clinical trial of testosterone replacement. Many interventional trials of the effects of testosterone on human health and disease have been conducted. There is considerable heterogenicity in terms of study design and these differences have a potential to significantly affect the results seen in various studies. Gonadal status at baseline and the testosterone level produced by testosterone treatment in the study are of particular importance because the effects of altering testosterone from subphysiological to physiological levels may be different from those of altering physiological levels to supraphysiological. Another important factor is the length of treatment. Randomised controlled trials of testosterone have ranged from one to thirty-six months in duration (Isidori et al 2005) although some uncontrolled studies have lasted up to 42 months. Many effects of testosterone are thought to fully develop in the first few months of treatment but effects on bone, for example, have been shown to continue over two years or more (Snyder et al 2000; Wang, Cunningham et al 2004).
Radical prostatectomy for the treatment of prostate cancer poses a significant risk of ED. A number of factors are associated with the chance of preserving erectile function. If both nerves that course on the lateral edges of the prostate can be saved, the chance of maintaining erectile function is reasonable. The odds depend on the age of the patient. Men younger than 60 years have a 75-80% chance of preserving potency, but men older than 70 years have only a 10-15% chance.
Testosterone is most commonly associated with sex drive in men. It also affects mental health, bone and muscle mass, fat storage, and red blood cell production. Abnormally low or high levels can affect a man’s mental and physical health. Your doctor can check your testosterone levels with a simple blood test. Testosterone therapy is available to treat men with low levels of testosterone. If you have low T, ask your doctor if this type of therapy might benefit you.
In one study, 9.6% reported ‘occasional’ erectile dysfunction, 8.9% reported erectile dysfunction occurring ‘often’, and 18.6% reported erectile dysfunction occurring ‘all the time’. Of these, only 11.6% had received treatment.In another study, only 14.1% of men reported that they had received treatment, despite experiencing erectile dysfunction for longer than 12 months.
Sally has a Bachelor's Degree in Biomedical Sciences (B.Sc.). She is a specialist in reviewing and summarising the latest findings across all areas of medicine covered in major, high-impact, world-leading international medical journals, international press conferences and bulletins from governmental agencies and regulatory bodies. At News-Medical, Sally generates daily news features, life science articles and interview coverage.
It seems that adequate testosterone levels are an important influence on sexual symptoms in the aging male and also influence the response of men to PDE-5 inhibitors, the first line treatment for erectile dysfunction in men. Many would now suggest screening for testosterone deficiency in all men presenting with erectile dysfunction (Gore and Rajfer 2004; Shabsigh 2005). This would seem appropriate because, in addition to benefits on sexual function, identification and treatment of hypogonadal men with testosterone could improve other symptoms of hypogonadism and protect against other conditions such as osteoporosis.
An international consensus document was recently published and provides guidance on the diagnosis, treatment and monitoring of late-onset hypogonadism (LOH) in men. The diagnosis of LOH requires biochemical and clinical components. Controversy in defining the clinical syndrome continues due to the high prevalence of hypogonadal symptoms in the aging male population and the non-specific nature of these symptoms. Further controversy surrounds setting a lower limit of normal testosterone, the limitations of the commonly available total testosterone result in assessing some patients and the unavailability of reliable measures of bioavailable or free testosterone for general clinical use. As with any clinical intervention testosterone treatment should be judged on a balance of risk versus benefit. The traditional benefits of testosterone on sexual function, mood, strength and quality of life remain the primary goals of treatment but possible beneficial effects on other parameters such as bone density, obesity, insulin resistance and angina are emerging and will be reviewed. Potential concerns regarding the effects of testosterone on prostate disease, aggression and polycythaemia will also be addressed. The options available for treatment have increased in recent years with the availability of a number of testosterone preparations which can reliably produce physiological serum concentrations.
Sugar is to testosterone what kryptonite is to Superman. Eliminating sugar is probably the single most powerful way to increase your performance, in part because sugar absolutely devastates your testosterone levels (but all carbs do not, especially under heavy training.) In one study of 74 men, a 75g dose of sugar – about the equivalent of a bottle of soda – decreased serum testosterone by 25% in under an hour, and levels stayed low for at least 2 hours [7]. On top of that, 15% of the men who started with normal testosterone dipped into the hypogonadal range after they ate sugar – that’s the range in which doctors diagnose men’s testes and women’s ovaries as failing. When you do eat carbs, stick to Bulletproof ones like sweet potatoes and squash. My recommendations for types of carbs and how often to eat them are here.
Rest and recovery is just as important as exercise, if not more so. Every time you do an intense workout, give yourself a minimum of 2 days to recuperate afterward, if not more. And don’t mix exercise with sleep hacking. If you’re exercising, get at least 8 hours of sleep every night. Your body uses it to rebuild, and you can throw your hormones out of whack if you don’t rest up properly. Here’s a more in-depth guide to Bulletproof weight training, complete with sample workouts.

Factors that mediate contraction in the penis include noradrenaline, endothelin-1, neuropeptide Y, prostanoids, angiotensin II, and others not yet identified. Factors that mediate relaxation include acetylcholine, nitric oxide (NO), vasoactive intestinal polypeptide, pituitary adenylyl cyclase–activating peptide, calcitonin gene–related peptide, adrenomedullin, adenosine triphosphate, and adenosine prostanoids.


early 15c., "physical weakness," also "poverty," from Middle French impotence "weakness," from Latin impotentia "lack of control or power," from impotentem (nominative impotens); see impotent. In reference to a want of (male) sexual potency, from c.1500. The figurative senses of the word in Latin were "violence, fury, unbridled passion." Related: Impotency.
For people who are worried about low or high testosterone, a doctor may perform a blood test to measure the amount of the hormone in the patient's blood. When doctors find low-T, they may prescribe testosterone therapy, in which the patient takes an artificial version of the hormone. This is available in the following forms: a gel to be applied to the upper arms, shoulders or abdomen daily; a skin patch put on the body or scrotum twice a day; a solution applied to the armpit; injections every two or three weeks; a patch put on the gums twice a day; or implants that last four to six months.
Hormone deficiency or hypogonadism, whether primary or secondary, has been thought to impact erectile function. Approximately a third of men in the European Male Aging Study demonstrated low testosterone, suggesting that hypogonadism is overrepresented among men with ED.11 Hormone deficiency, however, is less frequently the cause of ED than diabetes or vascular disease. Many entities with a strong relationship to ED also diminish bioavailable testosterone, including obesity, diabetes, and opioid use. Other hormones involved in testosterone metabolism or availability, like thyroid stimulating hormone and gonadotropins, also may impact erectile quality, presumably through regulating bioavailable testosterone. Understanding the relationship between testosterone and ED has been impaired by a lack of standardized measurement of this hormone and the cyclic nature of its release and consumption.

Impotence, also known as erectile dysfunction or ED, is a very common problem, affecting up to half of 40-70 year old men in Australia.Treatment techniques for impotence have varied through the years, from external steel mechanical attachments, to static electricity attached to the penis and testicles, to simple aphrodisiacs such as oysters. Until as recently as 1970, erectile failure was almost always seen as being due to psychological causes and was usually treated with psychotherapy.Since then, the medical causes contributing to impotence have been recognised and the treatment of impotence has been revolutionised, providing a range of options which are far more acceptable and very much more successful.Treatment options for impotenceTreatment choices for erectile dysfunction include:medicines;self-injection therapy;devices such as vacuum pumps;penile implant surgery;hormone therapy; andcounselling.If you have erectile dysfunction, the treatment your doctor recommends will depend on the severity of symptoms and the underlying cause of your impotence.Your doctor will want to check that any conditions that could be contributing to or causing erectile dysfunction are being treated.Your doctor may also suggest that you make some lifestyle adjustments, such as:increasing the amount of physical activity you get;losing weight if you are overweight;reducing the amount of alcohol you drink;quitting smoking; andnot taking illicit drugs.These lifestyle recommendations can help improve impotence related to several causes and improve your health in general.Medicines for erectile dysfunctionThe first tablet available for erectile dysfunction, sildenafil (brand name Viagra), has been largely responsible for helping to bring the topic of erectile dysfunction out into the open. Similar medications — tadalafil (Cialis) and vardenafil ( Levitra) — are also available. These medicines all work in a similar way, although there is some difference in how long their effect lasts. Sildenafil, tadalafil and vardenafil belong to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors because they block the PDE5 enzyme.How do oral medicines help treat erectile dysfunction?PDE5 inhibitors help in the process of getting and keeping an erection by working on chemicals in the body that are involved in erections. These medicines work by stopping PDE5 from breaking down an erection-producing chemical called cyclic guanosine monophosphate (cGMP). cGMP helps to relax the smooth muscle cells in the penis's erectile tissue, allowing more blood to flow into the penis to cause an erection. When PDE5 is temporarily blocked by these medicines, it can’t break down the erection producing cGMP, so an erection can be achieved and maintained. PDE5 inhibitors can be used in the treatment of erectile dysfunction that is due to physical or psychological causes.Medications such as Viagra, Cialis and Levitra will work only if you are sexually stimulated. They are not aphrodisiacs and won’t increase your sex drive.Side effects of PDE5 inhibitorsSide effects of these medicines can include headaches, flushes, blocked nose, indigestion and dizziness.In rare situations, sildenafil and vardenafil can cause a distortion of vision or change in colour vision.Tadalafil has been associated with back pain.Who can take medicines for impotence?PDE5 inhibitors cannot be taken by all men, so your doctor will need to evaluate your suitability before prescribing either of these medications.Men taking nitrates (often used to treat angina) should never take phosphodiesterase type 5 (PDE5) inhibitors. PDE5 inhibitors should also not be taken with some medicines used to treat high blood pressure.PDE5 inhibitors may also not be suitable for men with certain heart conditions or low blood pressure. Check with your doctor to find out if this type of medication may be suitable for you.Self-injection therapySelf-injection therapy delivers a medicine called alprostadil (brand name Caverject), also known as prostaglandin E-1, to the erectile tissue of the penis. Prostaglandin E-1 occurs naturally in the body and helps increase the blood flow to the penis to cause an erection. Unlike the PDE5 inhibitors, alprostadil will cause an erection whether the penis is stimulated or not.Self-injection therapy is usually recommended if PDE5 inhibitor medicines are not suitable or have not been effective in the treatment of erectile dysfunction.How to use self-injection therapyAlprostadil is injected into either of the 2 cigar-shaped chambers of the penis known as the corpora cavernosa, which run along the length of the penis, one on either side. Your doctor or urologist (specialist in problems with male reproductive organs and the urinary tract) will give you instructions on how to do this.Alprostadil should produce an erection in 5 to 20 minutes and, generally, the erection will last for 30 to 60 minutes.You should not use alprostadil more than once in a 24-hour period, and you should use it no more than 3 times a week.Don’t try to use more than the recommended dose of alprostadil, as your erection may last longer than is medically safe.Who can use self-injection therapy?You should ask your doctor if alprostadil is suitable for you. Your doctor will also be able to tell you how much alprostadil to use, depending on your condition and whether or not you are taking any other medications, and also how to use alprostadil properly.People with certain illnesses, such as leukaemia and sickle cell anaemia, or who have a penile implant or Peyronie’s disease, where the penis may be scarred and produces erections that are not straight, should not use alprostadil.Men for whom sexual activity is not advised should not use alprostadil.Side effects of injection therapyThe most common side effects of alprostadil include pain in the penis or bruising in the penis at the site of injection. Fibrosis (the development of fibrous tissue) can also develop following injections into the penis.The most serious side effect is priapism (a persistent erection), which is a medical emergency. Your doctor will inform you of what to do if you have an erection that persists for 2 hours or more. It is very important that you follow your doctor’s instructions and inform them that you have experienced this side effect.Vacuum erection devicesVacuum erection devices work by creating a vacuum, which increases blood flow to the penis, producing an erection.The penis is lubricated and placed inside a hollow plastic chamber. Air is pumped out of the chamber, either manually or by a battery powered pump. This creates a vacuum which pulls blood into the penis to cause an erection. This takes about 5 minutes.Once the penis is erect, the man fits a rubber ring around the base of his penis to keep the blood trapped inside the penis when the cylinder is removed. After intercourse, the ring can be removed to return the penis to a limp state.Vacuum erection devices avoid surgery and can be used as often as required. However, they may be difficult to use, and many men and their partners feel they take much of the pleasure and spontaneity away from sexual activities. Vacuum pumps are not suitable for men who have problems with blood clotting, or blood disorders such as leukaemia.Penile implant surgery for impotencePenile implant surgery is not a common procedure but in some cases it may be the most appropriate treatment for erectile dysfunction.The procedure involves placing an implant inside the penis, along its length, so that it can become erect. The implant may be a pair of semi-rigid rods or a pair of inflatable cylinders.The inflatable implants allow the penis to look and feel limp (flaccid) or erect, depending on how much the cylinders are inflated. The cylinders in an inflatable implant are hollow, and the man gets an erection by squeezing a pump located in his scrotum to fill the cylinders with salt water (saline) stored in a reservoir implanted in his lower abdomen. A release valve drains the saline out of the cylinders and back into the reservoir.With the semi-rigid, malleable rod type of implant, the rods run along the length of the penis and can be bent upwards to produce an erect penis, or downwards when an erect penis is not required.Like all surgery, there are some risks, such as infection or bleeding. If you have had surgery and have severe pain, fever, swelling or excessive bleeding, you should contact your doctor as soon as possible.Vascular surgery for erectile dysfunctionIn cases where a man’s anatomy prevents blood flow into or out of the penis, vascular surgery may be an option. This treatment option is rarely recommended, and is usually only successful in younger men.If there is a blockage that prevents blood from flowing into the penis, a doctor may recommend an operation that bypasses the blocked blood vessels, using a length of vein or manufactured tubing, to allow more blood to flow into the penis and help produce an erection.If the problem is that blood leaks back out of the penis, this can be corrected by tying off the major veins that drain the penis, a procedure known as venous ligation.Hormone treatments for impotenceIn a small number of men, blood tests may show abnormally low levels of testosterone, the male sex hormone. In such cases your doctor might prescribe a course of testosterone injections or a testosterone implant. The supplements can help boost sex drive as well as increasing the ability to have erections. Testosterone gel or patches, applied daily to the skin, are another option.Complementary medicines for erectile dysfunctionThere is a lack of scientific evidence supporting the effectiveness of complementary therapies for the treatment of impotence.Always check with your doctor before taking any herbal medicines or supplements for impotence. These formulations may contain ingredients that can interact with other medicines or cause dangerous side effects.Counselling for men with impotenceErectile dysfunction often has physical causes, but sometimes there is a psychological basis for erection problems. Often this is a form of performance anxiety. A man may have had an episode of erectile dysfunction due to some passing cause like fatigue, stress, relationship difficulty or intoxication. This may have led to embarrassment or a feeling of failure. Even if the physical cause does not remain, future attempts to have sex may trigger memories of this embarrassment and acute anxiety that it will happen again. This anxiety itself is capable of causing erectile dysfunction, and so a man may get trapped in a self-reinforcing cycle of anxiety and erectile dysfunction. In these instances, seeing a GP, counsellor or psychologist can be very helpful.Stress, anxiety, depression and low self-esteem, in fact, almost all significant emotional problems, can have a major effect on sexuality. So do many chronic physical illnesses, even if they don't directly affect genital function. Counsellors and psychologists can assist with these and a wide range of other sexual and relationship problems and can also help female partners suffering from sexual problems. They are particularly skilled in helping patients to overcome guilt or anxiety relating to sexual abuse, and in helping couples to sort out relationship difficulties. Simple problems can be dealt with in a few visits, but more complex problems may require several months or even years of therapy.Your doctor may be able to recommend a psychologist or counsellor who specialises in sexual and relationship problems. Last Reviewed: 12 December 2016
In addition to conjugation and the 17-ketosteroid pathway, testosterone can also be hydroxylated and oxidized in the liver by cytochrome P450 enzymes, including CYP3A4, CYP3A5, CYP2C9, CYP2C19, and CYP2D6.[151] 6β-Hydroxylation and to a lesser extent 16β-hydroxylation are the major transformations.[151] The 6β-hydroxylation of testosterone is catalyzed mainly by CYP3A4 and to a lesser extent CYP3A5 and is responsible for 75 to 80% of cytochrome P450-mediated testosterone metabolism.[151] In addition to 6β- and 16β-hydroxytestosterone, 1β-, 2α/β-, 11β-, and 15β-hydroxytestosterone are also formed as minor metabolites.[151][152] Certain cytochrome P450 enzymes such as CYP2C9 and CYP2C19 can also oxidize testosterone at the C17 position to form androstenedione.[151]
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There are treatments available to help you to get and maintain an erection. In addition, making healthy changes to your lifestyle could help with impotence. Switching to a healthier balanced diet, taking more exercise and cutting down on or giving up alcohol and cigarettes could help you to see an improvement in sexual function. If you think that the problem may be related to stress or anxiety, counselling can also help.
The effect excess testosterone has on the body depends on both age and sex. It is unlikely that adult men will develop a disorder in which they produce too much testosterone and it is often difficult to spot that an adult male has too much testosterone. More obviously, young children with too much testosterone may enter a false growth spurt and show signs of early puberty and young girls may experience abnormal changes to their genitalia. In both males and females, too much testosterone can lead to precocious puberty and result in infertility. 
In males, testosterone is required for the development of male sex organs such as increased penis and testes size. The hormone also promotes the development of sexual male characteristics during puberty such as voice deepening and the growth of armpit, chest and pubic hair. Testosterone plays an important role in maintaining sex drive, sperm production, muscle strength and bone mass. A healthy level of testosterone is also protective against bone disorders such as osteoporosis.
Diabetes. Erectile Dysfunction is common in people with diabetes. An estimated 10.9 million adult men in the U.S. have diabetes, and 35 to 50 percent of these men are impotent. The process involves premature and unusually severe hardening of the arteries. Peripheral neuropathy, with involvement of the nerves controlling erections, is commonly seen in people with diabetes.
The physical side effects of chemotherapy are usually temporary and resolve within one to two weeks after stopping the chemotherapy. However, chemotherapy agents, such as Ciplatin or Vincristine, may interfere with the nerves that control erection leading to possible impotence. Make sure you discuss potential side effects of cancer chemotherapy with your doctor or healthcare provider.
Talk with your doctor before trying supplements for ED. They can contain 10 or more ingredients and may complicate other health conditions. Asian ginseng and ginkgo biloba (seen here) are popular, but there isn't a lot of good research on their effectiveness. Some men find that taking a DHEA supplement improves their ability to have an erection. Unfortunately, the long-term safety of DHEA supplements is unknown. Most doctors do not recommend using it.
The partial synthesis in the 1930s of abundant, potent testosterone esters permitted the characterization of the hormone's effects, so that Kochakian and Murlin (1936) were able to show that testosterone raised nitrogen retention (a mechanism central to anabolism) in the dog, after which Allan Kenyon's group[183] was able to demonstrate both anabolic and androgenic effects of testosterone propionate in eunuchoidal men, boys, and women. The period of the early 1930s to the 1950s has been called "The Golden Age of Steroid Chemistry",[184] and work during this period progressed quickly. Research in this golden age proved that this newly synthesized compound—testosterone—or rather family of compounds (for many derivatives were developed from 1940 to 1960), was a potent multiplier of muscle, strength, and well-being.[185]
Alprostadil (also known as prostaglandin E1 [PGE1]) is the prominent known smooth-muscle dilator of the corpus cavernosum. Its mechanism of action is believed to be the promotion of intracellular accumulation of cyclic adenosine monophosphate, thereby causing decreased intracellular accumulation of calcium and resulting smooth muscle relaxation. Alprostadil can be delivered to the erectile tissue either via an intraurethral suppository that is massaged and then absorbed across the corpus spongiosum of the urethra to the corpora cavernosa, or directly injected into the corpora cavernosa. When administered urethrally, doses are substantially higher than when directly injected (typical dosing is 500 mcg to 1 mg intraurethral compared with 2.5 mcg to 20 mcg intracavernosal).
Testosterone is an androgen hormone produced by the adrenal cortex, the testes (in men), and the ovaries (in women). It is often considered the primary male sex hormone. Testosterone stimulates the development of male secondary sex characteristics (like body hair and muscle growth) and is essential in the production of sperm. In women, testosterone plays a role in egg development and ovulation.
The effects of testosterone in humans and other vertebrates occur by way of multiple mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors.[105][106] Androgens such as testosterone have also been found to bind to and activate membrane androgen receptors.[107][108][109]
At the present time, it is suggested that androgen replacement should take the form of natural testosterone. Some of the effects of testosterone are mediated after conversion to estrogen or dihydrotestosterone by the enzymes aromatase and 5a-reductase enzymes respectively. Other effects occur independently of the traditional action of testosterone via the classical androgen receptor- for example, its action as a vasodilator via a cell membrane action as described previously. It is therefore important that the androgen used to treat hypogonadism is amenable to the action of these metabolizing enzymes and can also mediate the non-androgen receptor actions of testosterone. Use of natural testosterone ensures this and reduces the chance of non-testosterone mediated adverse effects. There are now a number of testosterone preparations which can meet these recommendations and the main factor in deciding between them is patient choice.
The Organon group in the Netherlands were the first to isolate the hormone, identified in a May 1935 paper "On Crystalline Male Hormone from Testicles (Testosterone)".[177] They named the hormone testosterone, from the stems of testicle and sterol, and the suffix of ketone. The structure was worked out by Schering's Adolf Butenandt, at the Chemisches Institut of Technical University in Gdańsk.[178][179]
show that total testosterone levels increase after exercising, especially after resistance training. Low testosterone levels can affect your sex drive and your mood. The good news is that exercise improves mood and stimulates brain chemicals to help you feel happier and more confident. Exercise also boosts energy and endurance, and helps you to sleep better. Fitness experts recommend 30 minutes of exercise every day. 
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