In muscle cells, the creatine transporter is predominantly localized to the sarcolemmal membrane. Western blot analysis of creatine transporter expression revealed the presence of two distinc protein bands, migrating at 55kDa and 70kDa on reducing SDS-PAGE gels. The 73kDa band has been reported to be the predominant band in humans, with no differences based on gender. A more recent report demonstrated that the 55kDa creatine transporter variant is glycosylated, forming the 73 kDa protein. Therefore, the 55 and 75kDa protein bands are actually immature and mature/processed forms of the creatine transporter protein, respectively.
A: If your goal is the largest accrual of muscle mass possible then there may be some benefit to ingesting nutrients with a period of 30-60 minutes after your workout. Does this have to be a protein shake? No, but ideally it should be a meal lower in fat to enhance the digest rate of nutrients within the gastrointestinal tract. However, if you have just eaten a mixed macronutrient meal pre-workout then you should keep in mind that that meal is still likely digesting so there’s no need to throw down the weights after your last set and rush to your locker to slam a protein shake.
One pilot study using 150mg/kg creatine monohydrate for a five day loading phase followed by maintenance (60mg/kg) for the remainder of the five weeks noted that supplementation was associated with fewer muscle symptoms and complaints alongside improved muscular function, yet a later trial trying to replicate the obsevations using 150mg/kg daily for five weeks noted the opposite, that creatine supplementation exacerbated symptoms.
Older women with knee osteoarthritis given supplemental creatine at 20g for five days followed by 5g for the rest of the twelve week trial experienced improvements in stiffness (52% reduction), pain (45%), and physical function (41%) as assessed by WOMAC, despite no improvements in physical power output relative to placebo. This study paired supplementation and placebo with a mild exercise regimen.
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.
2. What's your training like? Are you crushing 25 sets for chest like the average juiced out bodybuilder? If so, there's a pretty good chance you might be working above your MRV (maximal recoverable volume) and as such any physiological adaptation which could have taken place is going to be minimal given the cellular environment which occurs in a state of functional overreaching.
Squats target both your inner and outer thighs. Use a barbell heavy enough to challenge your muscles but light enough that you can still control your form. Hold it behind your head with your feet shoulder-width apart. Tighten your core, then squat down as far as comfortable. There should be no knee or back pain. As you come back up, raise your hips and chest together.
Glutamine and beta-alanine are amino acids and HMB, beta-hydroxy-beta-methyl butyrate, is a byproduct of leucine, another amino acid. Promoting individual amino acids, the building blocks of protein, to enhance performance in the strength sports has been a particular focus of supplement manufacturers over the years. To date, the evidence for any advantage has been mixed and mostly unimpressive.
When looking for a whey protein powder to purchase, seek out powders that offer at least 20 g of protein per serving (one scoop) and are low in carbohydrates (aim for 5 g per serving or less). You may run into whey protein isolate, which looks attractive because it’s a higher concentration of protein. However, avoid this one as in the extreme processing, proteins are denatured that can render them less effective. In addition, these formulas are also often chock full of artificial sweeteners. Instead, look for powders from grass-fed cows that aren’t pumped with hormones.
Creatine is known to be present in the retina due to the expression of creatine kinase (CK) and the GAMT enzyme of creatine synthesis, which is also present in the mammalian retina. Creatine in the blood can be transported into the retina via the creatine transporter (confirmed in humans), and inhibiting transporter activity (by depleting the medium of chloride and sodium) reduces uptake by 80%. The fact that not all uptake was inhibited suggests that another transporter, such as the monocarboxylate transporter MCT12 (or SLC16A12), plays a role, perhaps moreso in the lens, where its levels were comparable to that of the major creatine transporter SLC6A8.
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(8):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(6):2299-305. View abstract.
^ Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, Candow DG, Kleiner SM, Almada AL, Lopez HL (2017-06-13). "International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine". Journal of the International Society of Sports Nutrition. 14: 18. doi:10.1186/s12970-017-0173-z. PMC 5469049. PMID 28615996.
Studies of so-called "smart drugs" have also been taken out of context. Some "smart" nutrients, available over the counter, are marketed as a way to "increase mental focus and concentration during training." The problem is that the studies they're based upon involved either animals or people with brain pathology. In normal people the effects of smart drugs remain unproven, except anecdotally.
Several studies have used either beet root juice or pomegranate extract in multi-ingredient performance supplements and have observed improvements in strength, hypertrophy, and performance in resistance-trained men. At this point, however, it's difficult to determine if these benefits are from beet root juice and pomegranate extract working alone or synergistically with other ingredients.[11,12]
Creatine citrate is creatine bound to citric acid, or citrate. Creatine citrate does not differ greatly from monohydrate in regard to absorption or kinetics. Note that creatine citrate is more water-soluble than monohydrate, but creatine absorption is generally not limited by solubility. The increased water solubility may play a factor in palatability.
Other human studies have yielded mixed results concerning creatine’s influence on triglyceride levels. In healthy male football players, creatine supplementation (5g monohydrate daily) over eight weeks did not influence triglyceride levels but in martial artists given approximately 3.5g daily, a statistically significant increase in triglycerides was found despite no changes in total cholesterol. In people with cardiovascular complications, given an exercise program and creatine, no significant change in triglycerides was noted relative to a placebo control group, which was also exercising.
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.