Bodybuilding developed in the late 19th century, promoted in England by German Eugen Sandow, now considered as the "Father of Bodybuilding". He allowed audiences to enjoy viewing his physique in "muscle display performances". Although audiences were thrilled to see a well-developed physique, the men simply displayed their bodies as part of strength demonstrations or wrestling matches. Sandow had a stage show built around these displays through his manager, Florenz Ziegfeld. The Oscar-winning 1936 musical film The Great Ziegfeld depicts the beginning of modern bodybuilding, when Sandow began to display his body for carnivals.
Lie on your back with knees bent and feet flat on the floor. Lift your hips to come into a bridge position with a neutral spine. Tuck your chin into your chest. Dig your elbows into the ground. Press the bottoms of your feet together and move your heels as close to your butt as possible. Inhale as you lower your hips toward the ground. Exhale as you lift your hips. Do 15 reps.

Put simply, "strength training means using resistance to create work for your muscles," says Hannah Davis, C.S.C.S. and author of Operation Bikini Body. So even if your mind jumps straight to those hardcore machines and massive weights, there are a lot of ways to create this resistance that require minimal equipment (or none at all). Bodyweight workouts can be an incredibly effective way to strength train. Squats and push-ups FTW. You can also use tools like dumbbells, medicine balls, TRX bands, resistance bands, kettlebells, and slider disks, to help get the job done, explains Davis. But if that sounds like gibberish don't worry about it. Keep it simple and focus on equipment-free routines first. No matter what you do, the most important thing is to find something that challenges you, says Davis.
Energy: Energy is found in amino acids, also known as creatine, produced naturally in the body and also found in meat such as beef, chicken and pork. The problem with naturally found creatine is that the amount of protein in it is not high, which therefore, draws bodybuilders to supplement it with a powdered version. Bodybuilders use creatine to increase anaerobic energy; this allows them to lift weights for longer periods of time. Creatine also helps to give volume to the muscle cells by adding more water in them, thus making them look fuller. 

Creatine supplementation at 300mg/kg for one week (loading with no maintenance) in youth subject to six repeated 35m sprints (10s rest, known as the Running-based Anaerobic Sprint Test or RAST) noted that the increased average and peak power output seen in creatine was not met with a reduction in fatigue, although there was an attenuation in inflammation from exercise (TNFα and CRP).[299]

It’s important to remember that since everybody is different, these estimates are just that. How the numbers work out for each person will definitely vary. So many factors—like genetics, hormones, sleep, and diet—can change the rate at which our bodies burn calories. And some people may have a harder time than others when it comes losing fat or gaining muscle—again, there are so many factors at play and our body chemistries are all different. Strength training is important for many, many, many other reasons (more on that later), but if you’re looking to increase your metabolism, it’s important to have realistic expectations and know that strength training can make a difference, but probably won’t drastically affect how many calories you burn from one day to the next.
Deldicque et al [32] found a 250%, 45% and 70% increase for collagen mRNA, glucose transporter 4 (GLUT4) and Myosin heavy chain IIA, respectively after 5 days creatine loading protocol (21 g/d). The authors speculated that creatine in addition to a single bout of resistance training can favor an anabolic environment by inducing changes in gene expression after only 5 days of supplementation.
Lifters who follow high-volume or high-intensity resistance-training programs, as many bodybuilders do, may also benefit from carbohydrate intake immediately post-workout. Compared with a placebo, carbohydrates combined with protein immediately post-workout and one hour after a bout of resistance exercise have been shown to increase insulin levels and rates of glycogen resynthesis.[19]
^ The effect of HMB on skeletal muscle damage has been assessed in studies using four different biomarkers of muscle damage or protein breakdown: serum creatine kinase, serum lactate dehydrogenase, urinary urea nitrogen, and urinary 3-methylhistidine.[38][41][42] When exercise intensity and volume are sufficient to cause skeletal muscle damage, such as during long-distance running or progressive overload, HMB supplementation has been demonstrated to attenuate the rise in these biomarkers by 20–60%.[38][42]
Myotonic Dystrophy type I (DM1) is an inhereted muscular disorder caused by an expanded CTG repeat in the DMPK gene on chromosome 19q13.3 (genetic cause of the disorder[561]) resulting in muscular degeneration and myotonia. The related myopathy, Myotonic Dystrophy type II (DM2) which is also known as proximal myotonic myopathy (PROMM) is due to a CCTG repeat on 3q,[562] and is less affected by myotonia and more by muscular pain and weakness. There is no cure for either because they are genetic disorders, so current therapies are aimed at reducing side-effects. Therapies include modafinil for the somnolence[563] and perhaps creatine for the reduction in strength and functionality.[548]
After supplementation of creatine monohydrate (loading phase, followed by 19 weeks maintenance), creatine precursors are decreased by up to 50% (loading) or 30% (maintenance), which suggests a decrease in endogenous creatine synthesis during supplementation.[38] This appears to occur through creatine’s own positive feedback and suppression of the l-arginine:glycine amidinotransferase enzyme, the rate-limiting step in creatine synthesis, as levels of intermediates before this stage are typically elevated by up to 75%.[38]
Remember that each person is unique, and each body responds differently to treatment. TT may help erectile function, low sex drive, bone marrow density, anemia, lean body mass, and/or symptoms of depression. However, there is no strong evidence that TT will help memory recall, measures of diabetes, energy, tiredness, lipid profiles, or quality of life.
In the early 2000s, the IFBB was attempting to make bodybuilding an Olympic sport. It obtained full IOC membership in 2000 and was attempting to get approved as a demonstration event at the Olympics, which would hopefully lead to it being added as a full contest. This did not happen and Olympic recognition for bodybuilding remains controversial since many argue that bodybuilding is not a sport.[11]
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.

K. Aleisha Fetters, M.S., C.S.C.S., is a Chicago-based personal and online trainer. She has a graduate degree in health and science reporting from the Medill School of Journalism at Northwestern University and regularly contributes to Men's Health, Women's Health,, TIME, and SHAPE. When she's not lifting something heavy, she's usually guzzling coffee and writing about the health benefits of doing so.

That being said, men aren’t the only ones who suffer from low testosterone levels. Women can also suffer from testosterone deficiency which can affect their overall well-being in addition to their sex drive. If you’re a woman or man concerned about your testosterone levels, in addition to using supplements like the ones below, you should contact your doctor who will be able to diagnose any deficiencies and recommend additional treatments.
Creatine is used up as energy during high intensity exercise. Due to this usage, the amount of glucose required from glycogen is decreased a bit. This both preserves glycogen concentrations in skeletal muscle and reduces lactate production, which is produced when glucose is oxidized for energy. There do not appear to be any alterations in the bioenergetic status of muscle cells during low to moderate intensity exercise.
Kerksick, C. M., Wilborn, C. D., Campbell, W. I., Harvey, T. M., Marcello, B. M., Roberts, M. D., Parker, A. G., Byars, A. G., Greenwood, L. D., Almada, A. L., Kreider, R. B., and Greenwood, M. The effects of creatine monohydrate supplementation with and without D-pinitol on resistance training adaptations. J.Strength.Cond.Res. 2009;23(9):2673-2682. View abstract.
Stronger muscles improve performance in a variety of sports. Sport-specific training routines are used by many competitors. These often specify that the speed of muscle contraction during weight training should be the same as that of the particular sport. Sport-specific training routines also often include variations to both free weight and machine movements that may not be common for traditional weightlifting.
CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.
The majority of your workouts should be comprised of compound exercises. Common examples include squats, deadlifts, lunges, bench presses, rows, pull-ups, lat pull-downs, overhead presses, and so on. Isolation exercises should definitely also be a part of your program, just a smaller part in comparison. Common examples include bicep curls, tricep extensions, chest flies, lateral raises, leg curls, leg extensions, calf raises, and so on.
Bodybuilders also train small muscles with a similar volume, frequency and intensity of their larger muscles. Strength athletes laugh at this. “Curls are a waste of time” is a common phrase you will hear hurled at a bodybuilder. This is SILLY. Although big compound movements should be most people’s resistance training priority, smaller muscle group focus work has some benefits for every athlete. Bicep tears are quite common among strength athletes, especially strong men and powerlifters. This happens because these competitors will lift tremendous weights with their backs, but their biceps are the weak link. Many of these injuries could be prevented with some good old-fashioned bodybuilder type isolation work. If you are only as strong as your weak link, doesn’t it make sense to make those weak links strong ones?

Muscle building supplements can serve as a great tool for helping you increase your muscle mass.  Always remember that, as when taking any supplement, it’s best to consult with your doctor to ensure that you won’t face any adverse interactions with medications or negatively affect your health. While the muscle building supplements listed are all generally safe, individuals with chronic health conditions should be especially careful.
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,[104][105][106][107] 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,[108] where both hypo- and hypersecretion (deficient- and excessive-secretion) of circulating androgens have negative effects on cognition.
Levels of testosterone naturally decrease with age, but exactly what level constitutes "low T," or hypogonadism, is controversial, Harvard Medical School said. Testosterone levels vary wildly, and can even differ depending on the time of day they're measured (levels tend to be lower in the evenings). The National Institutes of Health includes the following as possible symptoms of low testosterone:
Growth of spermatogenic tissue in testicles, male fertility, penis or clitoris enlargement, increased libido and frequency of erection or clitoral engorgement occurs. Growth of jaw, brow, chin, and nose and remodeling of facial bone contours, in conjunction with human growth hormone occurs.[21] Completion of bone maturation and termination of growth. This occurs indirectly via estradiol metabolites and hence more gradually in men than women. Increased muscle strength and mass, shoulders become broader and rib cage expands, deepening of voice, growth of the Adam's apple. Enlargement of sebaceous glands. This might cause acne, subcutaneous fat in face decreases. Pubic hair extends to thighs and up toward umbilicus, development of facial hair (sideburns, beard, moustache), loss of scalp hair (androgenetic alopecia), increase in chest hair, periareolar hair, perianal hair, leg hair, armpit hair.
When testosterone and endorphins in ejaculated semen meet the cervical wall after sexual intercourse, females receive a spike in testosterone, endorphin, and oxytocin levels, and males after orgasm during copulation experience an increase in endorphins and a marked increase in oxytocin levels. This adds to the hospitable physiological environment in the female internal reproductive tract for conceiving, and later for nurturing the conceptus in the pre-embryonic stages, and stimulates feelings of love, desire, and paternal care in the male (this is the only time male oxytocin levels rival a female's).[citation needed]

A testicular action was linked to circulating blood fractions – now understood to be a family of androgenic hormones – in the early work on castration and testicular transplantation in fowl by Arnold Adolph Berthold (1803–1861).[182] Research on the action of testosterone received a brief boost in 1889, when the Harvard professor Charles-Édouard Brown-Séquard (1817–1894), then in Paris, self-injected subcutaneously a "rejuvenating elixir" consisting of an extract of dog and guinea pig testicle. He reported in The Lancet that his vigor and feeling of well-being were markedly restored but the effects were transient,[183] and Brown-Séquard's hopes for the compound were dashed. Suffering the ridicule of his colleagues, he abandoned his work on the mechanisms and effects of androgens in human beings.

It's woooooorkkkkkiiiinnnngggg!!! I've been working out without creatine for over a year and a half now and have been missing that extra boost at the end of a set of reps. Not anymore! Started to feel the creatine help out in my 4th workout since using this stuff. It's good, real good. Creatine is one of those only supplements that have actually been proven to increase strength and bursts of endurance at the end of a set, and it's that one thing that can turn a regular workout into something that you're proud of. Just buy it, it works, you won't be disappointed. Use 2 of their servings sizes though, you need 5mg not 2.5. No spoon in bag, you'll need a measuring cup. Mixes effortlessly in juice.
Fast twitch (or Type II fibers) fire very quickly, but also fatigue quickly, so they don’t last long.  It gets a bit more complicated, because there are actually two types of fast twitch fibers. Type IIA fibers have some endurance qualities (used for things such as longer sprints). While Type IIX fibers are our “super fast” fibers, used only when a super short burst is needed (like a 100 m sprint or a really heavy lift).
Low testosterone levels can cause mood disturbances, increased body fat, loss of muscle tone, inadequate erections and poor sexual performance, osteoporosis, difficulty with concentration, memory loss and sleep difficulties. Current research suggests that this effect occurs in only a minority (about 2%) of ageing men. However, there is a lot of research currently in progress to find out more about the effects of testosterone in older men and also whether the use of testosterone replacement therapy would have any benefits.
Nephrectomized rats may have significantly reduced creatine synthesis rates[509] via impairment of methylation (the GAMT enzyme)[510] although creatine reuptake from the urine seems unimpaired.[511] Supplemental creatine in a rat model of 2/3rds nephrectomy (2% creatine in the diet) does not appear to negatively influence kidney function as assessed by the serum biomarkers of cystatin C and urinary protein or creatinine clearance rates.[512] Elsewhere, 2% creatine in the diet in rats for two weeks again failed to show negative effects on kidney function, but showed benefit in reducing homocysteine in late-stage uremic rats.[312] While there is not much human evidence for the rat nephrectomy model, a lone case study in a man with a single kidney failed to find an impairing effect of creatine (20g daily for five days and 5g for another month) in conjunction with a high protein diet.[513]

Lyoo, I. K., Yoon, S., Kim, T. S., Hwang, J., Kim, J. E., Won, W., Bae, S., & Renshaw, P. F. (2012, September). A randomized, double-blind placebo-controlled trial of oral creatine monohydrate augmentation for enhanced response to a selective serotonin reuptake inhibitor in women with major depressive disorder. American Journal of Psychiatry. 169(9):937-45. Retrieved from

In regard to the blood brain barrier (BBB), which is a tightly woven mesh of non-fenestrated microcapillary endothelial cells (MCECs) that prevents passive diffusion of many water-soluble or large compounds into the brain, creatine can be taken into the brain via the SLC6A8 transporter.[192] In contrast, the creatine precursor (guanidinoacetate, or GAA) only appears to enter this transporter during creatine deficiency.[192] More creatine is taken up than effluxed, and more GAA is effluxed rather than taken up, suggesting that creatine utilization in the brain from blood-borne sources[192] is the major source of neural creatine.[193][192] However, “capable of passage” differs from “unregulated passage” and creatine appears to have tightly regulated entry into the brain in vivo[193]. After injecting rats with a large dose of creatine, creatine levels increased and plateaued at 70uM above baseline levels. These baseline levels are about 10mM, so this equates to an 0.7% increase when superloaded.[193] These kinetics may be a reason for the relative lack of neural effects of creatine supplementation in creatine sufficient populations.

Creatine has demonstrated neuromuscular performance enhancing properties on short duration, predominantly anaerobic, intermittent exercises. Bazzucch et al [27] observed enhanced neuromuscular function of the elbow flexors in both electrically induced and voluntary contractions but not on endurance performance after 4 loading doses of 5 g creatine plus 15 g maltodextrin for 5/d in young, moderately trained men. Creatine supplementation may facilitate the reuptake of Ca2+ into the sacroplasmic reticulum by the action of the Ca2+ adenosine triphosphatase pump, which could enable force to be produced more rapidly through the faster detachment of the actomyosin bridges.
It was traditionally thought that total brain blood flow was not changed during physical activity. Research in the last 10 years, however, changed this perspective. We now understand that the increased neuronal and metabolic activity of the brain during exercise drive increases in blood flow to it. We have also learned that exercise that is too intense will reduce blood flow and oxygen delivery causing fatigue. So, what is the ideal intensity to stimulate blood flow to the brain, and perhaps, augment your mental abilities in the moment?

In regard to the loading period, two reviews suggest that the range of weight gain associated with creatine supplementation at 20g for 7 days is in the range of 0.9-1.8kg (1.98-3.96lbs).[612][613] The highest reported increase in water weight associated with creatine loading, although measured a month after loading started (after a maintenance phase) was 3.8kg (8.36lbs).[614]
The right amount of workout: It is highly possible that the protein powder you are taking doesn’t work on your body. Supplements should only be taken if you have a rigorous workout schedule or else, it will turn out to be of no value. Most people just purchase a box of supplements without really doing the math, which is very important. Unless you find out the dosage that suits you, the amount of time you should dedicate for the workout and so on, you must not expect daydream the results. 
You see, there is only so much muscle that the human body is capable of building in a given period of time. So, if you supply your body with MORE calories than it’s actually capable of putting towards the process of building new muscle… it’s not going to magically lead to additional muscle being built. It’s just going to lead to additional fat being gained.
For a 180 lb (82 kg) person, this translates to 25 g/day during the loading phase and 2.5 g/day afterward, although many users take 5 g/day due to the low price of creatine and the possibility of experiencing increased benefits. Higher doses (up to 10 g/day) may be beneficial for people with a high amount of muscle mass and high activity levels or for those who are non-responders to the lower 5 g/day dose.
In patients with DM1 given a short loading phase (10.6g for ten days) followed by a 5.3g maintenance for the remainder of an 8-week trial noted that supplementation resulted in a minor improvement in strength (statistical significance only occurred since placebo deteriorated) and no significant difference was noted in self-reported perceived benefits.[565] Maintaining a 5g dosage for four months also failed to significantly improve physical performance (handgrip strength and functional tests) in people with DM1, possible related to a failure to increase muscular phosphocreatine concentrations.[566]
In humans, studies that investigate links between serotonin and creatine supplementation find that 21 trained males, given creatine via 22.8g creatine monohydrate (20g creatine equivalent) with 35g glucose, relative to a placebo of 160g glucose, was found to reduce the perception of fatigue in hot endurance training, possibly secondary to serotonergic modulation, specifically attentuating the increase of serotonin seen with exercise (normally seen to hinder exercise capacity in the heat[233]) while possibly increasing dopaminergic activity (conversely seen to benefit activity in the heat[234]).[155]
The important role of nutrition in building muscle and losing fat means bodybuilders may consume a wide variety of dietary supplements.[41] Various products are used in an attempt to augment muscle size, increase the rate of fat loss, improve joint health, increase natural testosterone production, enhance training performance and prevent potential nutrient deficiencies.

Weight gain might be the most common side effect. “Creatine can cause your body to hold on to water by pulling fluid into your cells via osmosis,” says Bates. “It doesn't necessarily cause you to gain weight as fat, but it can increase edema, or water weight.” Also, muscle is denser than fat, so in some cases building muscle can increase body weight overall (even if you’re simultaneously burning fat).

Related to exercise and fitness, BCAAs are taken to help reduce muscle breakdown, which is why they may be known as muscle building supplements. Leucine, in particular, is known for playing an important role in muscle protein synthesis, which can help with muscle gain and maintenance. Some also claim that BCAAs can enhance performance, although many studies also refute this claim.

If a young man's low testosterone is a problem for a couple trying to get pregnant, gonadotropin injections may be an option in some cases. These are hormones that signal the body to produce more testosterone. This may increase the sperm count. Hedges also describes implantable testosterone pellets, a relatively new form of treatment in which several pellets are placed under the skin of the buttocks, where they release testosterone over the course of about three to four months. Injections and nasal gels may be other options for some men.
One study on 27 otherwise healthy men supplementing creatine (0.3g/kg loading for a week, 0.05g/kg thereafter for 8 weeks) with a thrice weekly exercise regiment noted that alongside greater increase in lean mass and power relative to placebo at 4 and 8 weeks, myostatin in serum decreased to a greater extent with creatine (around 17% at 8 weeks, derived from graph) than it did with placebo (approximately 7%).[356] Increases in GASP-1, a serum protein that inhibits the actions of myostatin by directly binding to it,[357] were not different between groups.[356]
A child’s ability to regenerate high energy phosphates during high intensity exercise is less than that of an adult. Due to this, creatine supplementation may benefit the rate and use of creatine phosphate and ATP rephosporylation. However, performance in short duration high-intensity exercise can be improved through training therefore supplementation may not be necessary [54].
Let's get one thing clear: It's all about the bum. Sure, built biceps fill out a shirt and six-pack abs are the prize of every beachgoer, but the back is where it's at. A bodacious booty is essential to a good physique—and not just for stage-bound fitness contestants. Everyone seems to want a great bum. Photos of posteriors flood the Internet and are often the most viewed—and "liked"—body part on social media. There's just something magical about a beautiful butt!

Creatine supplementation in the under 18 population has not received a great deal of attention, especially in regards to sports/exercise performance. Despite this, creatine is being supplemented in young, <18 years old, athletes [52,53]. In a 2001 report [52] conducted on pupils from middle and high school (aged 10 – 18) in Westchester County (USA) 62 of the 1103 pupils surveyed were using creatine. The authors found this concerning for 2 main reasons: firstly, the safety of creatine supplementation is not established for this age group and is therefore not recommended. Secondly, it was speculated that taking creatine would lead on to more dangerous performance enhancing products such as anabolic steroids. It is important to point out that this potential escalation is speculation. Furthermore, a questionnaire was used to determine creatine use amongst this age group and does not necessarily reflect the truth.
Magnesium-chelated creatine typically exerts the same ergogenic effects as creatine monohydrate at low doses.[78] It was created because carbohydrates tend to beneficially influence creatine metabolism and magnesium is also implicated in carbohydrate metabolism and creatine metabolism.[79][80] Magnesium chelated creatine may be useful for increasing muscle strength output with a similar potency to creatine monohydrate, but without the water weight gain, as there are noted differences, but they are statistically insignificant.[80][81]

It has been argued that purposely overtraining for a brief period can be beneficial. One article published by Muscle & Fitness magazine stated that you can "Overtrain for Big Gains". It suggested that if one is planning a restful holiday and does not wish to inhibit their bodybuilding lifestyle too much, they should overtrain before taking the holiday, so the body can recuperate and grow during the prolonged rest period. Overtraining can be used advantageously, as when a bodybuilder is purposely overtrained for a brief period of time to super compensate during a regeneration phase. These are known as "shock micro-cycles" and were a key training technique used by Soviet athletes.[53]
The US FDA reports 50,000 health problems a year due to dietary supplements [14] and these often involve bodybuilding supplements.[15] For example, the "natural" best-seller Craze, 2012's "New Supplement of the Year" by, widely sold in stores such as Walmart and Amazon, was found to contain N,alpha-Diethylphenylethylamine, a methamphetamine analog.[16] Other products by Matt Cahill have contained dangerous substances causing blindness or liver damage, and experts say that Cahill is emblematic for the whole industry.[17]
The incidence of liver damage from herbal and dietary supplements is about 16–20% of all supplement products causing injury, with the occurrence growing globally over the early 21st century.[2] The most common liver injuries from weight loss and bodybuilding supplements involve hepatocellular damage with resulting jaundice, and the most common supplement ingredients attributed to these injuries are catechins from green tea, anabolic steroids, and the herbal extract, aegeline.[2]
JAK2 (Janus-Activating Kinase 2) is a novel protein that has been shown to suppress the activity of the creatine transporter CrT in vitro. The effects of JAK2 on CrT are not well-understood in vivo, however. Given that growth hormone activates both c-src (increases CrT activity) and JAK2- which has been found to decrease CrT activity, it is plausible that JAK2 may function as a negative-feedback regulator of creatine uptake. Future research is needed to better understand the role of JAK2 on CrT activity in vivo.
Depression is a common psychological disorder affecting millions of people around the world. It results in severe sadness, loss of interest in activities, and difficulty performing daily tasks. It may be caused by common factors such as life events, genetic predisposition, conflict, and other psychological problems. However, low testosterone remains an, often missed cause of depression. In persons with low testosterone levels and depression, treatment includes testosterone replacement therapy as well as supportive measures including dietary modifications, increased activity, and use of natural supplements such as Tongkat Ali.
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 the hepatic 17-ketosteroid pathway of testosterone metabolism, testosterone is converted in the liver by 5α-reductase and 5β-reductase into 5α-DHT and the inactive 5β-DHT, respectively.[1][155] Then, 5α-DHT and 5β-DHT are converted by 3α-HSD into 3α-androstanediol and 3α-etiocholanediol, respectively.[1][155] Subsequently, 3α-androstanediol and 3α-etiocholanediol are converted by 17β-HSD into androsterone and etiocholanolone, which is followed by their conjugation and excretion.[1][155] 3β-Androstanediol and 3β-etiocholanediol can also be formed in this pathway when 5α-DHT and 5β-DHT are acted upon by 3β-HSD instead of 3α-HSD, respectively, and they can then be transformed into epiandrosterone and epietiocholanolone, respectively.[157][158] A small portion of approximately 3% of testosterone is reversibly converted in the liver into androstenedione by 17β-HSD.[156]
Supplementation of a loading phase of creatine has been noted to augment the increase in RBC levels of superoxide dismutase (SOD) from exercise, when measured immediately after, by 8.1%, but control groups increased to match within an hour.[299] Glutathione (normally decreases with exercise) and catalase (increases) were both unaffected,[299] and elsewhere in vitro red blood cells incubated with 3mM of creatine (within the supplemental range) is able to improve filterability (a measure of cell rheology, or fluid structure of the cell[300]) when RBC creatine was increased by 12.3% to reach 554µM.[301] This was thought to be due to reduced oxidative stress (assessed via MDA) in the red blood cells, which in the presence of 1-5mM creatine was progressively reduced by 20-41%.[301]