Electrolytes derive mainly from minerals in the diet and they maintain fluid balance and assist the nervous system to perform muscle contractions. Electrolytes are sodium, potassium, magnesium, calcium and chloride, bicarbonate, phosphate, sulfate. Exercisers are particularly dependent on sodium and potassium balance. Carbohydrates are important for fueling exercise, including vigorous weight training, and in post-exercise energy replacement nutrition. Carbohydrates, mostly sugars, are formulated in sports drinks with electrolytes such as sodium chloride and potassium and sometimes magnesium.
When it comes to building lean muscle, size bodybuilders are king. That’s their ultimate goal. Sure, Crossfit, powerlifting and all the other modalities will build muscle, but that’s not their focus. They want performance and any muscle they build is a side effect. Not so with bodybuilding where muscle size and shape are the priorities. Learning how to build muscle for the sake of building muscle has some benefits to the performance athlete. It allows for ais less injury prone. Its also a fact that bigger muscle contract harder regardless of technique or form, so it’s a good strategy to throw in some bodybuilder muscle building sessions here and there to give yourself stronger muscles to then train for performance. Build the muscle bigger, then train it to perform better.
Diet – To boost your body’s testosterone levels, you need to reduce your intake of foods that promote an increase in your belly fat. Increase in belly fat promotes the activity of an enzyme called aromatase which converts testosterone to the female sex hormone, estrogen. Therefore, the greater the amount of belly fat you have, the more your level of testosterone reduces. In addition, increase your intake of heart-healthy foods such as fiber from whole grains, lean white meat, fresh fruits, and vegetables and reduce your intake of red meat and animal fat.
Creatine is a naturally occurring compound found in muscle in large amounts. Creatine monohydrate is the supplement form and combines is a combination of the amino acids arginine, glycine, and methionine. Creatine drives the important creatine phosphate energy pathway, which is important in high-intensity activity such as weightlifting. Creatine can improve body bulk and training performance in high-intensity activities. Be aware that not everyone responds to creatine supplementation and 30 percent of users may not see any improvement. Women may not benefit as much as men. In weight training, increased strength, bulk, and fat loss are reasonably consistent results.
In your body, you can only store enough ATP for about 10 seconds of maximum exercise, this means that after those storages are depleted, it is up to your body to produce ATP to reach the demand your body is placing. [5] Creatine helps in the body by increasing stores of phosphocreatine which is the main ingredient used to create new ATP during intense exercise. By just supplementing creatine for 6 days, you can double your levels of creatine in your muscle storages, resulting in a higher capacity to create energy. [5]
In the 1970s, bodybuilding had major publicity thanks to the appearance of Arnold Schwarzenegger, Franco Columbu, Lou Ferrigno, and others in the 1977 docudrama Pumping Iron. By this time, the IFBB dominated the competitive bodybuilding landscape and the Amateur Athletic Union (AAU) took a back seat. The National Physique Committee (NPC) was formed in 1981 by Jim Manion,[7] who had just stepped down as chairman of the AAU Physique Committee. The NPC has gone on to become the most successful bodybuilding organization in America and is the amateur division of the IFBB. The late 1980s and early 1990s saw the decline of AAU-sponsored bodybuilding contests. In 1999, the AAU voted to discontinue its bodybuilding events.

If you're using a resistance band, keep in mind that one band might not cut it for your entire body. Different muscles have different strengths, so you may want to buy two different resistance bands in different thickness, which determines how difficult they'll be to use. In general, if you're able to complete 8 reps of an exercise using a band, you'll want to select another that provides a greater amount of resistance. 
Our Keep-It™ guarantee is valid for the first-time purchase of a formula, and redeemable up to three months (90 days) after the purchase date. Multiple bottles, foods, apparel and gear do not fall under this guarantee, however, they may be applicable for return. Fitness equipment, personal care products, knowledge purchases, and DVDs are not eligible for return or refund. For more information and a full list of products that qualify, visit our Keep-It™ page. Further details can be found on our Refund Policy support page.
But when a premenopausal woman’s testosterone levels are too high, it can lead to polycystic ovary syndrome (PCOS), a condition that increases the risk of irregular or absent menstrual cycles, infertility, excess hair growth, skin problems, and miscarriage. High levels of testosterone in women, whether caused by PCOS or by another condition, can cause serious health conditions such as insulin resistance, diabetes, high cholesterol, high blood pressure, and heart disease. (12)
I'm 6'1" 175 pounds 27 years old. I would like to increase my general muscle mass and reduce my stomach fat. I would consider myself and ectomorph (hard gainer) as I have never really developed much muscle while I've always been very active in sports and periodic weight training. Over the past year I lost about 30 pounds (nearly all fat) by reducing my caloric intake effectively and regular whole body exercises. I was on my way to my ideal body composition until I became a bike courier. I've been a bike messenger for 9 months and recently my stomach fat has started to return. I'm riding 50+ miles each weekday riding for 9 hours a day. How many calories should I be eating? I've tried everywhere between 2400-3,500 cal/day. Is it possible for me to be eating too few calories while still accumulating stomach fat? Is it realistic for me to be able to maintain or even build muscle mass in this scenario? Please help, thanks.
Practice Sleep Hygiene – For optimal health of your mind and body, it is recommended that adults get 7 to 8 hours of sleep every day. Lower or more amounts of sleep can exacerbate your depressive symptoms. Sleep hygiene practices include limiting daytime naps, scheduling a regular sleep and wake-up times, and ensuring the environment is rid of potential sleep disruptors such as light, noise, and heat.
Professor Marcos FrankToday, important stuff happened to you. Tonight, when you sleep, your brain will extend the process of turning that stimulation – the sites, sounds, thoughts, emotions, facts, etc. – into memories that you can access at a moments notice in the future. It’s amazing when you think about it: experiences, facts, skills, and even thought patterns become a part of who we are. How much do you know now that you didn’t know 1o to 15 years ago, or even last week, last month, or yesterday? The process of accumulating information, and accessing when needed, is so routine it’s easy to forget that something is going to make it possible. As it turns out, sleep plays a vital role in the formation of certain types of memories. In this interview, I speak with someone who has made, and continues to make, significant contributions to help the world better understand how all this magic works. My guest is Marcos Frank, Ph.D., who is the Interim Chair of the Department of Biomedical Sciences in the Elson S. Floyd College of Medicine at Washington State University. I hope you enjoy this discussion as much as I did.
Standing with your feet hips distance apart, hold a barbell or free weights at shoulder height (either the barbell resting above your shoulder blades on your back, or free weights resting on top of your shoulder muscles held in front of you). Keeping your spine in a neutral position move into the squat by retracting your hips and pulling them backward. Hinging at your hips, bend your knees until your thighs come almost parallel to the ground (knees should be directly over your feet). Then push back up until your back is straight and repeat 5–10 times depending on the weight you’re using. 

Neurological and cognitive function has also been shown to be improved by creatine supplementation [47,48]. Rawson and Venezia [49] review the effects of creatine supplementation on cognitive function highlighting that higher brain creatine has been associated with improved neuropsychological performance. Creatine supplementation protocols have been shown to increase brain creatine and phosphocreatine contents. Cognitive processing hindered due to sleep deprivation and natural impairment due to aging can be improved by creatine supplementation. This review also highlights other possible benefits of creatine ingestion to older adults, such as improvements in: fatigue resistance, strength, muscle mass, bone mineral density, and performance of activities of daily living. Some of these benefits occur without concurrent exercise. The authors inform that discrepancies between studies do exist and are hard to explain but may be possibly due to differences in diet, race and/or supplementation protocols. However, the ideal dose of creatine to maximize brain uptake is not known. Patients have been supplemented with 40 g while in healthy adults positive results have been reported with around 20 g per day [49].


Conflicting results have been obtained concerning the importance of testosterone in maintaining cardiovascular health.[29][30] Nevertheless, maintaining normal testosterone levels in elderly men has been shown to improve many parameters that are thought to reduce cardiovascular disease risk, such as increased lean body mass, decreased visceral fat mass, decreased total cholesterol, and glycemic control.[31]

According to the abstract, in the stratified analyses by forms of aerobic exercise, weekly resistance exercise of 1 time or 1-59 minutes was associated with lower risks of total cardiovascular events and cardiovascular disease, regardless of meeting the aerobic exercise guidelines. The analysis showed that resistance training reduced the risk of cardiovascular events in 2 ways: training had a direct association with cardiovascular risk, and resistance training indirectly lowered cardiovascular risk by decreasing body mass index.
Brain injury. Early research shows that taking creatine by mouth daily for 7 days increases the ability to exercise by increasing lung function in people with a spinal cord injury. However, other research shows that creatine does not improve wrist muscle or hand function. Early research also shows that taking creatine by mouth daily for 6 months reduces amnesia following a traumatic brain injury in children.
Spillane M, Schoch R, Cooke M, Harvey T, Greenwood M, Kreider R, Willoughby DS. The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels. J Int Soc Sports Nutr. 2009;6:6. doi: 10.1186/1550-2783-6-6. [PMC free article] [PubMed] [CrossRef]
The Branched-Chain Amino Acids, BCAAs for short, are leucine, valine and isoleucine.  Essentially, its a form of protein powder for muscle gain or other uses. These essential amino acids are not made by the body but are found in foods such as meats, dairy products and legumes. In medicine, BCAAs are used for a number of conditions, however, for many uses, further research is necessary to determine whether or not treatment is effective.

I’m 6 foot and 154 pounds and I’m thinking of using this diet to bulk up before I do a cut to shed body fat for a more lean look. How good would this diet be to maintain body fat while building muscle and how much muscle could you expect to put on. Thanks. I do not want to gain that much body fat while bulking and if possible I would just like to maintain my current body fat while bulking.


Moreover, the Food and Drug Administration (FDA) has identified numerous products marketed as bodybuilding or muscle-building dietary supplements that contain hidden active ingredients, including prescription drugs and steroid and steroid-like ingredients. Not only do these ingredients pose serious health risks, they might cause you to pop positive on a drug test. The only way to be sure a product contains only what’s on the label is to look for one that has been evaluated by an independent, third-party organization. For more information, visit FDA’s Consumer Update about bodybuilding products.
In another case, supplements touted as "myostatin blockers" were formulated from a type of sea algae. In a test tube, they effectively blocked the activity of the protein myostatin, which inhibits muscular growth in the body. The supplement ads implied that they'd enable you to develop unprecedented levels of muscular growth, but as it turned out, they didn't actually work in the human body.
You may find this hard to believe, but some common breakfast foods like Kellogg’s corn flakes and Graham crackers were invented 100 years ago to lower male libido. Kellogg and Graham believed that male sexual desire was the root of society’s problems, so they set out to make bland foods that would take away libido (this is absolutely true; look it up). That low fat, grain-based thing absolutely works wonders for lowering testosterone.

Glycogen synthesis is known to respond directly and positively to cellular swelling. This was demonstrated in an earlier study, during which rat muscle cells were exposed to a hypotonic solution in vitro to induce cell swelling, which increased glycogen synthesis by 75%. In contrast, exposing these same cells to a hypertonic solution hindered glycogen synthesis by 31%. These changes were not due to alterations in glucose uptake, but are blocked by hindering the PI3K/mTOR signaling pathway.[112] It was later noted that stress proteins of the MAPK class (p38 and JNK) as well as heat shock protein 27 (Hsp27) are activated in response to increasing osmolarity.[113][114] Furthermore, activation of MAPK signaling in skeletal muscle cells is known to induce myocyte differentiation[115] via GSK3β and MEF2 signaling, which can induce muscle cell growth.[116][117]
Due to this relative deficiency-state in vegetarians and vegans, some aspects of creatine supplementation are seen as more akin to normalizing a deficiency, rather than providing the benefits of supplementation. In young vegetarians, but not omnivores, creatine supplementation can enhance cognition.[60][61] The increased gain in lean mass may be more significant in vegetarians, relative to omnivores.[59] Supplementation of creatine in vegetarians appears to normalize the gap in storage between vegetarians and omnivores.[62] This is possibly related to a correlation seen in survey research, where vegetarianism and veganism appear to be more commonly affected by some mental disorders like anxiety and depression.[63]
However, if you increase the demands you are placing on your body by increasing the weight being lifted, lifting the same weight for additional reps, or just doing something that increases the demands that your body needs to meet, then your body will have no other choice but to make the changes and improvements necessary for it to adapt to this environment and remain capable of performing these tasks.

When endothelial cells have a higher creatine concentration, they appear to be mildly less permeable when incubated with 0.5-5mM creatine, while the higher concentration (5mM) is able to fully ablate TNF-α-induced neutrophil adhesion and both E-selectin and ICAM-1 expression.[316] This effect was prevented with ZM241385, an A2A (adenosine) receptor antagonist,[316] and since adenosine released by this receptor is known to be protective of endothelial cells,[317][318] it is thought that creatine works vicariously through this receptor and adenosine release, thought to be due to releasing ATP (occurs in response to stress[319][320]) which protects the cell via the A2A signaling system.[316]
As a ingredient that has been tested time and time again and shown to positively affect the building of muscle, GAT has taken the highest-quality compound to create Essentials Creatine. Using HPLC-tested pharmaceutical grade creatine that's tested to be 99.9% pure, Essentials Creatine provides 5 grams in every serving which can increase muscle size, boost strength, and enhance muscle recovery. Keep Reading »
One of the biggest goals of bodybuilders is to increase their muscle size and strength. Bodybuilding supplements often contain many ingredients that help to encourage this. Branched-chain amino acids are a common ingredient that can significantly increase muscle growth. Other ingredients help to increase the levels of hormones, such as growth hormone and testosterone, that can also stimulate muscle growth.

If you are underweight or have a naturally scrawny build, you may struggle to gain weight, let alone muscle mass, no matter what you do. Eating at all hours of the day and night can be exhausting and require frequent trips to the grocery store. Unless you are overweight, you likely need to create a caloric surplus in order to gain muscle. With a weight gainer powder, you can supplement a healthy diet with the additional calories you need to gain weight in muscle.
If you touch your phone between exercise sets, it better be to set its timer to 30 to 90 seconds. When lifting for hypertrophy, rest periods of 30 to 90 seconds encourage a quick release in muscle-building hormones (including testosterone and human growth hormone) while also making sure that you really, truly fatigue your muscles, according to Fitzgerald. 

It also had a purpose. It turns out posing in powerful stances causes your testosterone to increase within 20 minutes [13,14]. In those two studies, power posing for just a few minutes also dropped cortisol and boosted confidence. It’s a great way to start your day, or to give yourself an edge before a job interview or a big presentation. They don’t call it “warrior pose” for nothing!
So how does that play out in the real world? Well, if, for example, a woman adds 10 pounds of muscle and loses 10 pounds of fat, she’ll burn 40 extra calories per day. Forty calories a day isn’t nearly as significant as a dietary change could be, but for people who are looking to lose weight, it can still make a minor difference over the long term.

Creatine is classified as a "dietary supplement" under the 1994 Dietary Supplement Health and Education Act and is available without a prescription. Creatine is not subjected to FDA testing, and the purity and hygienic condition of commercial creatine products may be questionable [21]. A 1998 FDA report lists 32 adverse creatine-associated events that had been reported to FDA. These include seizure, vomiting, diarrhea, anxiety, myopathy, cardiac arrhythmia, deep vein thromboses and death. However, there is no certainty that a reported adverse event can be attributed to a particular product [22]. A recent survey of 28 male baseball players and 24 male football players, ages 18 to 23, found that 16 (31%) experienced diarrhea, 13 (25%) experienced muscle cramps, 7 (13%) reported unwanted weight gain, 7 (13%) reported dehydration, and 12 reported various other adverse effects [23].
Athletes in ancient Greece were advised to consume large quantities of meat and wine. A number of herbal concoctions and tonics have been used by strong men and athletes since ancient times across cultures to try to increase their strength and stamina.[5] In the 1910s, Eugen Sandow, widely considered to be the first modern bodybuilder in the West, advocated the use of dietary control to enhance muscle growth. Later, bodybuilder Earle Liederman advocated the use of "beef juice" or "beef extract" (basically, consomme) as a way to enhance muscle recovery. In 1950s with recreational and competitive bodybuilding becoming increasingly popular Irvin P. Johnson began to popularize and market egg-based protein powders marketed specifically at bodybuilders and physical athletes. The 1970s and 1980s marked a dramatic increase in the growth of the bodybuilding supplement industry, fueled by widespread use of modern marketing techniques and a marked increase in recreational bodybuilding.
^ Jump up to: a b Wallimann T, Wyss M, Brdiczka D, Nicolay K, Eppenberger HM (January 1992). "Intracellular compartmentation, structure and function of creatine kinase isoenzymes in tissues with high and fluctuating energy demands: the 'phosphocreatine circuit' for cellular energy homeostasis". The Biochemical Journal. 281 ( Pt 1) (Pt 1): 21–40. doi:10.1042/bj2810021. PMC 1130636. PMID 1731757.

Anti-cancer effects have been observed with the creatine analogue cyclocreatine[456][104][457] and have been replicated with creatine itself. These effects tend to be a reduction in which the rate of implanted tumors progresses.[458][459] It is suspected that these observed effects (inhibition of growth or attenuation of the rate of growth) are not due to the bioenergetic effect of creatine, secondary to creatine kinase. These anti-cancer effects do not have a known reliability, as the expression of creatine kinase varies widely based on the type of tumor.[460] However, some studies suggest an inverse relationship between tumor progression in mice and concentrations of creatine in cells, with creatine depletion coinciding with tumor development.[460]


It arises from the posterior gluteal line of the inner upper ilium, a pelvic bone, and roughly the portion of the bone including the crest of the ilium (the hip bone), immediately above and behind it; and from the posterior surface of the lower part of the sacrum, the base of the spine, and the side of the coccyx, the tailbone; from the aponeurosis of the erector spinae (lumbodorsal fascia), the sacrotuberous ligament, and the fascia covering the gluteus medius (gluteal aponeurosis). The fibers are directed obliquely downward and lateralward; The gluteus maximus has two insertions:
The process of phagocytosis (a macrophage consuming a pathogen) in macrophages appears to be associated with an acute reduction in creatine phosphate stores (45%)[436] and an increase in creatine kinase activity,[290] although prolonged stimulation is met with an increase in creatine phosphate (20%).[290] The creatine kinase activity does not appear to be altered based on creatine availability,[290] but since ATP seems to be preserved in these instances,[436][290] the increase in phosphocreatine may be explained by an overall creatine pool paralleling that found in medium.[290]
While many of the claims are based on scientifically based physiological or biochemical processes, their use in bodybuilding parlance is often heavily colored by bodybuilding lore and industry marketing and as such may deviate considerably from traditional scientific usages of the terms. In addition, ingredients listed have been found at times to be different from the contents. In 2015, Consumer Reports reported unsafe levels of arsenic, cadmium, lead and mercury in several of the protein powders that were tested.[7]
Another part of training isn't just doing the exercises, it's resting between the exercises. This comes with experience, but the general rule is, the higher the reps, the shorter the rest. So, if you're doing 15 reps, you might rest about 30 to 60 seconds between exercises. If you're lifting very heavy, say 4 to 6 reps, you may need up to two or more minutes.
Han:SPRD‐cy rats (human polycystic kidney disease model[514][515]) have pre-existing renal damage, which is accelerated upon ingestion of creatine supplementation at 0.3% of the diet for five days and 0.03-0.05% for the next 35 days (equivalent to human loading and maintenance).[516] During this particular disease state, renal water content and size progressively increases.[514][515] Since creatine supplementation furthered the increase by an additional 2.1%, it was thought that this property of creatine explained the 23% increased cyst scores seen relative to control.[516]

“This study establishes testosterone levels at which various physiological functions start to become impaired, which may help provide a rationale for determining which men should be treated with testosterone supplements,” Finkelstein says. “But the biggest surprise was that some of the symptoms routinely attributed to testosterone deficiency are actually partially or almost exclusively caused by the decline in estrogens that is an inseparable result of lower testosterone levels.”
^ Butenandt A, Hanisch G (1935). "Umwandlung des Dehydroandrosterons in Androstendiol und Testosterone; ein Weg zur Darstellung des Testosterons aus Cholestrin" [About Testosterone. Conversion of Dehydro-androsterons into androstendiol and testosterone; a way for the structure assignment of testosterone from cholesterol]. Hoppe-Seyler's Z Physiol Chem (in German). 237 (2): 89–97. doi:10.1515/bchm2.1935.237.1-3.89.
Some of these signs and symptoms can be caused by various underlying factors, including medication side effects, obstructive sleep apnea, thyroid problems, diabetes and depression. It's also possible that these conditions may be the cause of low testosterone levels, and treatment of these problems may cause testosterone levels to rise. A blood test is the only way to diagnose a low testosterone level.
Whey protein contains high levels of all the essential amino acids and branched-chain amino acids. It also has the highest content of the amino acid cysteine, which aids in the biosynthesis of glutathione. For bodybuilders, whey protein provides amino acids used to aid in muscle recovery.[27] Whey protein is derived from the process of making cheese from milk. There are three types of whey protein: whey concentrate, whey isolate, and whey hydrolysate. Whey concentrate is 29–89% protein by weight whereas whey isolate is 90%+ protein by weight. Whey hydrolysate is enzymatically predigested and therefore has the highest rate of digestion of all protein types.[27]

In other primates, gluteus maximus consists of ischiofemoralis, a small muscle that corresponds to the human gluteus maximus and originates from the ilium and the sacroiliac ligament, and gluteus maximus proprius, a large muscle that extends from the ischial tuberosity to a relatively more distant insertion on the femur. In adapting to bipedal gait, reorganization of the attachment of the muscle as well as the moment arm was required.[4]
Testosterone is only one of many factors that influence aggression and the effects of previous experience and environmental stimuli have been found to correlate more strongly. A few studies indicate that the testosterone derivative estradiol (one form of estrogen) might play an important role in male aggression.[66][71][72][73] Studies have also found that testosterone facilitates aggression by modulating vasopressin receptors in the hypothalamus.[74]
One study lasting 16 months using 10g creatine daily alongside the pharmaceutical riluzole noted that, after 34 of the patients died from ALS, creatine failed to exert protective effects against ALS-related mortality (adjusted hazard ratio of 0.78 with a 95% CI of 0.47–1.48[505]). A smaller study measuring only eight deaths noted that the six in placebo (relative to two in creatine) was too small of a sample size to detect a statistically significant difference.[506] A nonsignificant trend to increase survival has been noted elsewhere with 5g of creatine daily with a similar ratio: 3 deaths in placebo to 1 death in creatine.[507]
This muscle-building, power-enhancing supplement has an extremely high safety profile and a plethora of evidence to support its efficacy. Creatine supplementation works by increasing the availability of creatine and phosphocreatine (PCr) within the muscle, helping to maintain energy during high-intensity exercise such as weightlifting. Furthermore, increasing the availability of PCr may help speed up recovery between sets.

Studies that use a dosage range typical of creatine supplementation (in the range of 5g a day following an acute loading period) note increases to total body water of 6.2% (3.74lbs) over 9 weeks and[608] 1.1kg over 42 days.[609] Interestingly, some studies comparing creatine paired with training against training itself fail to find a significant difference in percentage of water gained (which is inherently to activity) with standard oral doses of creatine[609][607][610] (although low dose creatine supplementation of 0.03g/kg or 2.3g daily doesn’t appear to increase water retention[611]) despite more overall water weight being gained, due to an equal gain of dry mass in muscles. One study has quantified the percentage increase in mass of muscle cells to be 55% water, suggesting the two groups are fairly equal.[609]


Creatine is produced endogenously at an amount of about 1 g/d. Synthesis predominately occurs in the liver, kidneys, and to a lesser extent in the pancreas. The remainder of the creatine available to the body is obtained through the diet at about 1 g/d for an omnivorous diet. 95% of the bodies creatine stores are found in the skeletal muscle and the remaining 5% is distributed in the brain, liver, kidney, and testes [1]. As creatine is predominately present in the diet from meats, vegetarians have lower resting creatine concentrations [2].
Another part of training isn't just doing the exercises, it's resting between the exercises. This comes with experience, but the general rule is, the higher the reps, the shorter the rest. So, if you're doing 15 reps, you might rest about 30 to 60 seconds between exercises. If you're lifting very heavy, say 4 to 6 reps, you may need up to two or more minutes. 

Yuri Elkaim is one of the world’s most trusted health and fitness experts. A former pro soccer player turned NYT bestselling author of The All-Day Energy Diet and The All-Day Fat Burning Diet, his clear, science-backed advice has transformed the lives of more than 500,000 men and women and he’s on a mission to help 100 million people by 2040. Read his inspiring story, “From Soccer to Bed to No Hair on My Head” that started it all.
It doesn’t get more natural than getting a good night’s sleep. Research published in the Journal of the American Medical Association showed that lack of sleep can greatly reduce a healthy young man’s testosterone levels. That effect is clear after only one week of reduced sleep. Testosterone levels were particularly low between 2 and 10 p.m. on sleep-restricted days. Study participants also reported a decreased sense of wellbeing as their blood testosterone levels dropped.
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