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.
Creatine is vital for brain function, which has mechanisms to take up creatine, as well as regulate its intake. Although the diet appears to be the major source of creatine (and thus lack of dietary intake could cause a non-clinical deficiency) excess levels of creatine do not appear to “super-load” the brain similar to muscle tissue. Due to kinetics, creatine appears to be more “preventative” or acts to restore a deficiency in the brain. This is in contrast to creatine effects in muscle cells, where it can affect performance substantially on an acute timescale.
Knowledge – When it comes to building the best physique possible, you have to be willing to experiment and learn from your body. No one will be able to tell you what’s the most effective nutrition or training split for your individual genotype. Not only that, they don’t know your personal preference, injury history, asymmetries, experience level, or current work capacity.
That means it's an important part of your overall fitness and it benefits people of all ages, plus it may be particularly important for people with health issues such as obesity, arthritis, or a heart condition. The Centers for Disease Control Prevention physical activity guidelines recommend that adults do muscle-strengthening activities on at least two or more days each week (targeting the legs, hips, back, abdomen, chest, shoulders, and arms). (2)
Creatine is a natural source of energy for muscle contraction. The body produces creatine in the liver, kidneys, and pancreas. People can also get creatine by eating meat or fish. (Vegetarians may have lower amounts of creatine in their bodies.) Most of the creatine in the body is stored in skeletal muscle and used during physical activity. The rest is used in the heart, brain, and other tissues.
I’m glad you found some good information from this article. For any of these supplements, I would suggest talking to your doctor and pharmacist. I would suggest thinking about why you are interested in taking testosterone. Are you looking to increase muscle size? Bulk up? Knowing your fitness goals will help you determine which products are appropriate for you.
Exercise is highly effective in increasing your lean body mass, which is essentially muscle. In a study published in 2012, progressive resistance training helped men ages 50 to 83 gain an average of 2.4 pounds of lean body mass over an average of 20.5 weeks. Progressive resistance training involves performing weight bearing exercises. In addition, you must slowly increase the challenge of the exercise over time by increasing the weight, reps and/or sets. Studies show that either increasing reps or weight amount will work. So, if you don’t want to lift more weight, you can just do more reps and still build muscle.
When Katula started his research on whether weight training would improve quality of life for seniors, he realized that many had never even picked up a dumbbell. “They first had to learn how to use these big intimidating weights and machines,” he says. He recalls the story of one woman who protested that she couldn’t do the leg press machine. Finally, Katula persuaded her to sit in the machine and set the weight at 50 pounds. “I couldn’t believe how fast she whipped out 10 reps,” he says, “When she got out of that machine, she was two inches taller just from increased pride.”
The creatine transporter is a sodium[139][140] and chloride[141][142] dependent membrane-associated transporter that belongs to the Na+/Cl-dependent family of neurotransmitter transporters.[143] In muscle cells and most other cell types,[131][141] the isomer of the creatine transporter is known as SLC6A8 (solute carrier family 6, member 8). SLC6A8 is encoded by the gene present on the Xq28 region of the human X-chromosome and is expressed in most tissues.[144] A related gene encoding a creatine transporter variant has also been identified at 16p11.1 that is expressed exclusively in the testes.[145] These two transporters share 98% homology.[144][145]

2-4 Minutes Rest: Ideal for “tension exercises,” which includes most primary compound exercises. I personally take 3 minutes for the big stuff, sometimes going into the 3-4 minute range depending on exactly what I’m doing and what I feel like I need at the time. Since making strength gains is the main focus of these exercises, longer rest periods like this will be optimal for making it happen.
So it was popular then, but is it effective now? Just because something is popular doesn’t mean it works. In the case of creatine supplementation, however, you can be confident that increased muscle strength and less fatigue is possible. All thanks to a critical chemical reaction taking place in your muscle cells. Read on and learn how creatine works and why it lives up to that nostalgic ‘90s hype.
Those 5-pound dumbbells were a great place to start as a beginner, but if you've been lifting weights for a while, it's time to bump up the weight. “You can use both exercise machines and free weights,” explains Michele Olson, PhD, exercise physiologist, professor of exercise science at Auburn University Montgomery, “but, if you are not lifting heavy enough weight, it doesn’t matter if you are primarily using free weights or machines.” In order to build muscle, you must break down muscle tissue using a weight that is challenging enough to cause micro-tears, which when repaired, form denser, stronger fibers.
If you'’re looking to add muscle mass to your frame, hitting the weights hard is a given. Quality time in the gym begins a cascade of changes that will stimulate your muscles to grow bigger in response to the challenges you throw their way. It'’s tempting to think that'’s all it takes to add muscle to your body. After all, you can actually feel your biceps growing after an intense set of curls.
Intensive weight training causes micro-tears to the muscles being trained; this is generally known as microtrauma. These micro-tears in the muscle contribute to the soreness felt after exercise, called delayed onset muscle soreness (DOMS). It is the repair of these micro-traumas that results in muscle growth. Normally, this soreness becomes most apparent a day or two after a workout. However, as muscles become adapted to the exercises, soreness tends to decrease.[22]
Creatine is found in many protein supplements at baseline in the form of creatine monohydrate. If you take a protein supplement, you may already be getting creatine. What makes this creatine so special? Like the protein supplement above, this creatine supplement contains no artificial sweeteners or dyes. It contains 5000mg of creatine per dose and includes certain compounds to increase the bioavailability of the creatine, allowing it to be better absorbed.
Do Belgian squats (or "single leg squats") with a dumbbell. Hold out in front of your chest a dumbbell using both hands. Standing in front of a bench, lift your right leg back so that it's parallel to the floor and resting comfortably on the bench. Bend into a squat using the left leg, so that the right knee almost hits the floor. Lift and repeat 3 x 8. Repeat using opposite leg.
Tribulus Terrestris: A fruit from the Mediterranean, this supplement has been used in the Indian traditional medicine of Ayurveda. In addition to helping increase testosterone, many people take it to increase libido and as a cardioprotective aid. (10) Unfortunately, despite the fact that there are claims that tribulus terrestris can increase testosterone levels, studies don’t back up these claims.  There is some evidence, however, that it may improve athletic performance. If you want to choose one of the supplements for men, this should be your pick.
Gualano, B., de, Salles Painelli, V, Roschel, H., Lugaresi, R., Dorea, E., Artioli, G. G., Lima, F. R., da Silva, M. E., Cunha, M. R., Seguro, A. C., Shimizu, M. H., Otaduy, M. C., Sapienza, M. T., da Costa, Leite C., Bonfa, E., and Lancha Junior, A. H. Creatine supplementation does not impair kidney function in type 2 diabetic patients: a randomized, double-blind, placebo-controlled, clinical trial. Eur.J.Appl.Physiol 2011;111:749-756. View abstract.
Beast Creature could be another good option for female athletes. It’s tasty, it contains five types of creatine, and it contains ingredients that could improve fat loss by increasing insulin sensitivity. One potential bonus is that it also has 70 percent of your daily biotin, a nutrient often included in women’s multivitamins due its purported benefits for hair and nails.
Creatine may preserve dopamine synthesis in the striatum of mice (while protecting against dopaminergic depletion) when fed to mice at 2% of the diet for one week prior to MPTP toxicity[230]. This is possibly secondary to increasing tyrosine hydroxylase activity, the rate-limiting step of dopamine biosynthesis.[210][235] Two percent creatine was as protective as 0.005% rofecoxib (a COX2 inhibitor), but the two were additive in their protective effects (highly synergistic in regard to DOPAC by normalizing it, but not synergistic in preserving HVA).[230]
Finally, starvation (nutrient deprivation for four days) appears to increase activity of the creatine transporter secondary to decreasing serine phosphorylation (SGK target)[173] with no influence on tyrosine phosphorylation (c-Src target).[173] Starvation-induced increases in creatine influx do not necessarily mean more phosphocreatine, however, due to a depleted cellular energy state.[173]
Although creatine is a natural component of food, the amount of food required to supersaturate the muscle with PCr may not be feasible. For example, it could require 22 pounds of meat daily [8]. If creatine monohydrate is proven to be a safe and effective ergogenic aid, creatine supplementation may be the simplest way to increasing muscle stores. It may be beneficial to avoid caffeine if taking creatine supplements. One study showed that caffeine diminished strength gains seen with creatine use [9].
One case study on a subject with a methylentetrahydrofolate reductase (MTHFR) 677TT homozygote, a relatively common genetic mutation known as “mild MTHFR deficiency,” which causes mild homocysteinemia,[310] has seen benefits due to creatine supplementation where homocysteine was approximately halved (49% reduction) while CT heterozygotes and CC homozygotes (n=9) were unaffected.[311] Additionally, one rat study suggested a possible role for creatine in reducing homocysteine levels in a model of high uric acid levels (model for end stage renal disease[312]) but this was not replicated when investigated in humans.[313]
Liquid creatine has been shown to be less effective than creatine monohydrate.[69] This reduced effect is due to the passive breakdown of creatine over a period of days into creatinine, which occurs when it is suspended in solution.[70] This breakdown is not an issue for at-home use when creatine is added to shakes, but it is a concern from a manufacturing perspective in regard to shelf-life before use.
Creatine supplementation has once been noted to improve wellbeing and fatigue resistance in people with DM2, but has twice failed for people with DM1. In all three studies, it has failed to improve power output. This is thought to be due to a reduction in the expression of the creatine transporter preventing an increase in muscular phosphocreatine content.
^ 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.

This is why I never understand why girls who don’t want to “get bulky” are told by trainers to do 3 sets of 10-12 (or 5 sets of 1,000 reps of bicep curls with a 1 lb pink dumbbell). While it’s difficult for women to gain any sort of size lifting in ANY rep range, if we were trying to gain muscle size, that’s EXACTLY what we would want to do (as it would be causing sarcoplasmic hypertrophy).

This basic form of creatine comes in two forms, one of which involves the removal of the monohydrate (which results in creatine anhydrous) that converts to creatine monohydrate in an aqueous environment,[66][67] but due to the exclusion of the monohydrate it is 100% creatine by weight despite creatine monohydrate being 88% creatine by weight, as the monohydrate is 12%. This allows more creatine to be present in a concentrated formula, like capsules.[68]


de Salles Painelli V, Alves VT, Ugrinowitsch C, et al. Creatine supplementation prevents acute strength loss induced by concurrent exercise. Eur J Appl Physiol 2014;114:1749-55.del Favero S, Roschel H, Artioli G, et al. Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance. Amino Acids 2012;42:2299-305. View abstract.
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]
A double-blind study provided 20 g/day of creatine monohydrate for 5 days to qualified sprinters and jumpers who performed 45 seconds of continuous jumping and 60 seconds of continuous treadmill running. Supplementation enhanced performance in the jumping test by 7% for the first 15 seconds and 12% for the next 15 seconds, but there was no difference for the final 15 seconds. There was a 13% improvement in the time of intensive running to exhaustion [12].
As I mentioned earlier, the exercises that come first in your workout (aka primary compound exercises) should usually be done in the 5-8 rep range. Exercises in the middle (aka your secondary compound exercises) should usually be done in the 8-10 rep range. Exercises done at the end of your workout (which is typically where isolation exercises belong) should usually be done in the 10-15 rep range.

Gualano, B., de, Salles Painelli, V, Roschel, H., Lugaresi, R., Dorea, E., Artioli, G. G., Lima, F. R., da Silva, M. E., Cunha, M. R., Seguro, A. C., Shimizu, M. H., Otaduy, M. C., Sapienza, M. T., da Costa, Leite C., Bonfa, E., and Lancha Junior, A. H. Creatine supplementation does not impair kidney function in type 2 diabetic patients: a randomized, double-blind, placebo-controlled, clinical trial. Eur.J.Appl.Physiol 2011;111:749-756. View abstract.
When lifting any weight, you’ve got a concentric (hard) and eccentric (easy) phase. For instance, as you lower into a squat, you’re performing an eccentric action. When you return to standing, that’s concentric. And, according to research published in the European Journal of Applied Physiology, eccentric work is far better at triggering hypertrophy.

Although creatine is a natural component of food, the amount of food required to supersaturate the muscle with PCr may not be feasible. For example, it could require 22 pounds of meat daily [8]. If creatine monohydrate is proven to be a safe and effective ergogenic aid, creatine supplementation may be the simplest way to increasing muscle stores. It may be beneficial to avoid caffeine if taking creatine supplements. One study showed that caffeine diminished strength gains seen with creatine use [9].
A previous meta-analysis [28] reported an overall creatine supplementation effect size (ES) of 0.24 ± 0.02 for activities lasting ≤30 s. (primarily using the ATP- phosphocreatine energy system). For this short high-intensity exercise, creatine supplementation resulted in a 7.5 ± 0.7% increase from base line which was greater than the 4.3 ± 0.6% improvement observed for placebo groups. When looking at the individual selected measures for anaerobic performance the greatest effect of creatine supplementation was observed on the number of repetitions which showed an ES of 0.64 ± 0.18. Furthermore, an increase from base line of 45.4 ± 7.2% compared to 22.9 ± 7.3% for the placebo group was observed. The second greatest ES was on the weight lifted at 0.51 ± 0.16 with an increase from base line of 13.4 ± 2.7% for the placebo group and 24.7 ± 3.9% for the creatine group. Other measures improved by creatine with a mean ES greater than 0 were for the amount of work accomplished, weight lifted, time, force production, cycle ergometer revolutions/min and power. The possible effect of creatine supplementation on multiple high intensity short duration bouts (<30 s) have shown an ES not statistically significant from 0. This would indicate that creatine supplementation might be useful to attenuate fatigue symptoms over multiple bouts of high-intensity, short duration exercise. The ES of creatine on anaerobic endurance exercise (>30 – 150s), primarily using the anaerobic glycolysis energy system, was 0.19 ± 0.05 with an improvement from baseline of 4.9 ± 1.5 % for creatine and -2.0 ± 0.6% for the placebo. The specific aspects of anaerobic endurance performance improved by creatine supplementation were work and power, both of which had a mean ES greater than 0. From the findings of this previous meta-analysis [28] it would appear that creatine supplementation has the most pronounced effect on short duration (<30s) high intensity intermittent exercises.

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]
Do standard/oblique crunches. Lie down on a mat and position both arms behind your head without locking the hands. Bend your knees so that your feet are flat on the ground. Pushing the small of your back into the ground, slowly roll your shoulders off the ground only a couple of inches (not to a full sitting position). Don't use your momentum to help you up; use slow, regulated movements. Repeat 3 x 20.
In fact, in one new study comparing the effects of aerobic exercise versus resistance training on the psychological health of obese adolescents, researchers found that people in the resistance group experienced significantly greater self-esteem and perceived strength over four weeks. But what’s most interesting is that the feeling of getting stronger — rather than any measurable gains — was all it took to give them a boost.
It is suggested [16,37] that another mechanism for the effect of creatine could be enhanced muscle glycogen accumulation and GLUT4 expression, when creatine supplementation is combined with a glycogen depleting exercise. Whereas it has been observed [38] that creatine supplementation alone does not enhance muscle glycogen storage. Hickner et al [15] observed positive effects of creatine supplementation for enhancing initial and maintaining a higher level of muscle glycogen during 2 hours of cycling. In general, it is accepted that glycogen depleting exercises, such as high intensity or long duration exercise should combine high carbohydrate diets with creatine supplementation to achieve heightened muscle glycogen stores [39].

Research shows that strength training is especially effective at raising EPOC. That’s because, generally speaking, strength-training sessions cause more physiological stress to the body compared to cardiovascular exercise, even higher-intensity cardio intervals. However, it’s worth noting that overall exercise intensity is what makes the biggest impact on EPOC. So squats, deadlifts, and bench presses with heavy weights are going to be much more effective at raising EPOC compared to bicep curls and triceps extensions with light weights.
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