Xtend™ from Scivation - XTEND is a precise, scientific blend of Energy Aminos consisting of the proven 2:1:1 ratio of Branched Chain Amino Acids (L-Leucine, L-Isoleucine and L-Valine), Glutamine, Citrulline Malate, and Vitamin B6 that will give you the energy you need to maximize your training while enhancing recovery at the same time. The advanced components in Xtend have been scientifically proven to help:

- Speed Recovery
- Enhance ATP production and promote cell volumization.
- Decrease muscle breakdown and cortisol levels.
- Avoid fatigue by blocking entry of fatigue-inducing tryptophan into the brain.
- Increase protein synthesis, immune function and digestive health.
- Promote vasodilation which can lead to better assimilation and absorption of protein.
- Elevate growth hormone levels.

Xtend
• BCAA
• L-Glutamine
• Citrulline Malate

What Are Branched-Chain Amino Acids?
The BCAA Are A Group Of Three Essential Amino Acids:

1. Leucine
2. Isoleucine
3. Valine

The BCAA are different from the other 17 amino acids in that they are primarily metabolized in skeletal muscle (Layman, 2003) and metabolized at a much lower rate in the liver (Norton, 2005). The rate limiting enzyme in BCAA catabolism is Branched Chain Keto Acid Dehydrogenase, which is much more active in skeletal muscle than in the liver (Norton, 2005).

Point blank, exercise promotes increased BCAA oxidation (Shirmomura et al., 2004). This increased degradation of BCAA helps maintain energy homeostasis by providing carbon as a direct energy source and glucose homeostasis by providing substrates for the citric-acid cycle and gluconeogenesis.

Amino acids are categorized as glucogenic, ketogenic, or a combination of glucogenic and ketogenic. A glucogenic amino acid when metabolized gives rise to pyruvate or other TCA cycle intermediates that can be used for the production of glucose through gluconeogenesis.

A ketogenic amino acid is metabolized via the fatty acid pathway and gives rise to actyl-CoA, a fatty acid precursor. Leucine is completely ketogenic, valine is completely glucogenic, and isoleucine is both glucogenic and ketogenic. Valine and isoleucine can both be used to produce intermediates for glucose production via gluconeogenesis.

Due to leucine's metabolic properties (discussed below), increasing attention is being given to it and its metabolism. Research has shown plasma leucine levels to decrease during both aerobic and anaerobic exercise (Mero, 1999).

According to Freund and Hanani (2002), "Complete oxidation of leucine in the muscle yields more adenosine triphosphate molecules on a molar basis than complete oxidation of glucose." So leucine can provide skeletal muscle with more ATP than an equal amount of glucose, which is due to leucine being completely ketogenic and metabolized via the fatty acid pathway.

In order to meet the increased demand for BCAA during exercise the body breaks down muscle tissue to supply additional BCAA. By supplying the body exogenous BCAA during exercise, one can meet the increased demand for BCAA oxidation without breaking down muscle tissue to supply the needed BCAA.

Because BCAA serve as a "fuel" for skeletal muscle, supplementing with additional BCAA during your workout improves your performance without the added calories or insulin spike (which can lead to fat storage) caused by carbohydrates.

Leucine Stimulates Leptin Expression through mTOR activation in Adipocytes

Intake of leucine stimulates expression of the hormone leptin in adipocytes (the primary site of leptin secretion) through activation of the mTOR pathway (Meijer and Dubbelhuis, 2003). Leptin is a very complicated hormone; the gist of it is involved in the regulation of metabolism, body weight, and appetite.

Leptin secretion is linked with body fat levels; higher body fat is associated with higher leptin secretion and lower body fat is associated with lower leptin levels. When you diet and lose fat, the amount of leptin you secrete decreases, which makes your body "crave" food in an attempt to bring your body fat level back up to where the body is comfortable (known as the body fat "set point").

Leucine has the ability to activate leptin expression and will cause the body to think it is "fed" or receiving "adequate" calories, which will keep things running (specifically your metabolism) smoothly.

BCAA and the Glucose-Alanine Cycle

The BCAA's are involved in maintaining glucose homeostasis through the glucose-alanine cycle (see figure 1). The glucose-alanine cycle involves pyruvate (derived from glucose/glycogen) being transaminated in muscle to form alanine, with the BCAA serving as the main nitrogen source (donors) for the synthesis of alanine (Holecek, 2002).

The newly synthesized alanine is released in the blood stream and sent to the liver where it is converted into glucose through gluconeogenesis. This glucose can then be sent from the liver back to the working muscle to be used as fuel. Supplementing with BCAA allowing your body to create glucose to use for fuel without the added calories or insulin spike (which can lead to fat storage) caused by carbohydrates.

L-Glutamine

Glutamine is a glucogenic (glucose creating), nonessential amino acid that has multiple roles in the body. Glutamine is synthesized mainly in skeletal muscle and the liver and acts as a "nitrogen shuttle" between organs, a fuel for cells of the immune system and intestines, and a precursor for nucleotide synthesis (Holecek, 2002).

Glutamine is also a powerful cell volumizer (Haussinger et al. 1993). An increase in cell volume, also called cell swelling, stimulates anabolic pathways (synthesis of proteins and glycogen) and inhibits catabolic pathways (protein degradation) (Haussinger, 1993).

According to Houston (2001), "Glutamine content in skeletal muscle and other tissues appears to have a regulatory role in whole body protein synthesis." Glutamine levels inside muscle govern protein synthesis and nitrogen balance and therefore muscle growth (VanAcker et al. 1999).

Adequate glutamine concentrations are needed for optimal health and skeletal muscle hypertrophy. Therefore one would want to keep glutamine levels elevated, especially during/post exercise.

Glutamine Metabolism and Exercise

During times of stress, such as exercise, skeletal muscle glutamine levels are depleted. This glutamine released from skeletal muscle is derived from muscle proteins, the intramuscular free amino acid pool, and newly synthesized glutamine (VanAcker, 1999). The newly synthesized glutamine is created by using BCAAs obtained from muscle protein breakdown (Holecek, 2002).

Plasma and muscle glutamine levels are decreased post workout and it can take hours before they are restored (Rowbottom, 1996). A study examining the effect of free-form glutamine and glutamine peptide ingestion on muscle glycogen resynthesis found that plasma glutamine was decreased by 20% post workout with the ingestion of glucose only (control), showed no change with ingestion of whey protein or wheat protein hydrolysate plus glucose drinks, and a 200% increase with ingestion of free-form glutamine plus glucose drink (VanHall, 2000). Free-form glutamine supplementation was needed to elevate plasma glutamine levels post workout.

In addition to restoring and elevating plasma glutamine levels, oral glutamine supplementation increases muscle glycogen storage to the same capacity as glucose (Bowtell, 1999). Glutamine can replenish glycogen levels without the added calories or insulin spike (which can lead to fat storage) caused by carbohydrates.

Mammalian Target of Rapamycin (mTOR)

The Mammalian Target of Rapamycin (mTOR) is one of the body's protein synthesis regulators. mTOR functions as an energy sensor; it is activated when ATP levels are high and blocked when ATP levels are decreased (AMPK is activated when ATP decreases, which works antagonistically to mTOR).

The main energy-consuming process in the cell is protein synthesis. When mTOR is activated (high ATP levels sensed) protein synthesis is increased and when mTOR is suppressed (low ATP levels are sensed) protein synthesis is blunted.

MTOR activation is vital for skeletal muscle hypertrophy. Interestingly, mTOR is also a nutrient sensor of amino acid availability, specifically of leucine availability. Research has shown that regulation of mTOR by ATP and amino acids act independently through separate mechanisms (Dennis et al., 2001).

It is my belief that combining supplements that increase/elevate ATP levels with BCAA will lead to an increased activation of mTOR, and therefore protein synthesis. Our goal is to keep ATP levels elevated while working out. To do so, we must supply the needed nutrients and substrates before and after the workout to keep ATP levels elevated and our bodies primed for growth. This can be accomplished by supplementing with Citrulline Malate.

Citrulline-Malate

Citrulline-Malate has been shown to increase the rate of oxidative ATP production during exercise and the rate of phosphocreatine replenishment post exercise (Bendahan, 2002). Increasing the rate of ATP production during exercise would assist in allowing mTOR to be activated by the BCAA.

Citrulline-Malate also has anti-fatigue properties due to its ability to decrease ammonia levels and prevent against metabolic acidosis (Callis, 1991). Decreasing the sensation of fatigue would allow one to workout harder and longer, and thereby burn more calories and lose more fat.

Supplement Facts
Serving Size: 2 Scoops (11.5 grams)
Servings Per Container: 30
Amount Per Serving % Daily Value*
Vitamin B6 (as Pyroxidine HCl) 10 mg 167%
L-Leucine 3.5 g †
L-Glutamine 2.5 g †
L-Isoleucine 1.75 g †
L-Valine 1.75 g †
Citrulline Malate 1 g †

* Percent Daily Values are based on 2,000 calorie diet.
† Daily Value Not Established.

Ingredients:
L-Leucine, L-Glutamine, L-Valine, L-Isoleucine, Citrulline Malate, Natural and Artificial Flavors, Potassium Citrate, Citric Acid, Acesulfame Potassium, Sucralose, Pyridoxine HCl, Red #40, Blue #1



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What is Xtend?

Xtend is a precise, scientific blend of “Energy Aminos” consisting of the proven 2:1:1 ratio of Branched Chain Amino Acids (L-Leucine, L-Isoleucine and L-Valine), Glutamine, Citrulline Malate, and Vitamin B6.

If I already eat a lot of protein, will additional free-form BCAA be beneficial to me?

The metabolic effects seen from ingesting free-form amino acids are different from ingesting the same amino acids when they are in a whole protein (peptide bond). The rapid flushing of the system with the particular amino acid exerts a much more powerful activation of its target pathways. For example, if you were to ingest 5 grams of free-form arginine pre-workout you would notice a greater pump then without it. If you were to ingest 5 grams of arginine in the form of a whole protein (1) you’d have to eat a ton of protein to acquire the 5 grams of arginine and (2) the rate of delivery would be much slower and (3) you would not be flooding your system with a large dose of arginine at one time. The same holds true for BCAA. Ingesting 10 grams of BCAA will lead to greater activation of mTOR, PI3K, etc.* than ingesting 10 grams of BCAA from a whole protein.

*refer to my BCAA for more info on these pathways: http://www.bodybuilding.com/fun/beast11.htm

What if I already take in a lot of whey protein which is high in BCAA?

Free-form amino acids are absorbed quicker than whey, and as stated above, whey will not flood your bloodstream with BCAA as quick as ingesting free-form BCAA. The BCAA from whey compared to free-form BCAA could be compared to filling up a glass of water from a garden hose (whey) to a faucet (free-form BCAA). If you use a garden hose you have to wait until the water travels the length of the hose before you can use it. With a faucet, the water is right there when you turn it on. On top of this, the faucet has a wider opening than the garden hose and releases more water than the garden hose. During your workout and times of stress (dieting), you want the BCAA to get to your muscles as quickly as possible.

I have heard one can get the same effects from taking Leucine alone as from taking all 3 BCAA, is this true?

Due to leucine's metabolic properties, many people focus solely on leucine and not the other two BCAAs, valine and isoleucine. Research has shown that leucine-rich diets or administration of leucine alone lead to decreases in valine and isoleucine plasma concentrations and a BCAA imbalance (Shirmomura et al., 2004). While it may be cheaper to supplement with leucine alone instead of all three BCAA, one should supplement with all three BCAA so not to create a BCAA imbalance.

Isoleucine and Valine also has some interesting properties of their own, separate from leucine. Isoleucine has been shown to increase glucose intake via PI3K activation, one of the same pathways leucine uses, but independently of the mTOR pathway (Doi et al., 2003). Valine has been shown to reduce fatty acid synthase in adipocytes by 40%, which will lead to less fat storage (Taylor & Halperin, 1975).

Can women take Xtend?

Yes. Xtend is very effective for both men and women.

How much and when should I take Xtend?

How much Xtend you take per day will depend primarily on how much money you can spend and your goals. The following dosing protocols are based on the large tub of Xtend, which has 90 servings.

3 Servings during Your Workouts Strategy

During exercise BCAA oxidation is increased. Supplementing with additional BCAA spares muscle tissue from being broken down to acquire BCAA. Therefore, drinking Xtend around and during your workout is the ideal way to use it. Start sipping your Xtend 15 minutes prior to the start of your workout (i.e. while driving to the gym). Continue sipping Xtend between sets during your workout and finish whatever Xtend you have not drunken immediately post workout. Follow this up with your usual post-workout shake or meal. If you only use Xtend during your workouts, 1 jug will last as follows:

            If you want to take additional Xtend on your rest days to accelerate recovery and growth, 1 jug will last:

Sipping Xtend throughout the Day Strategy

Another popular method for using Xtend is to sip it throughout the day. Many users of this method have reporting gaining lean mass while losing fat simultaneously. This method would be ideal for those cutting on a low-carb, hypocaloric diet. Simply put the desired amount of Xtend in a container (i.e. gallon jug) and drink from it occasionally throughout the day. We would recommend using 4-6 scoops in a shaker bottle as pictured here:
 

If you use 3 servings (6 scoops) per day in this manner, 1 jug of Xtend will last 30 days. If you combine this method with the above method of taking 3 servings of Xtend during your workout, 1 jug will last:

Cardiovascular Training
Different scenarios:
(1) Cardio only
(2) Cadio AM, Weight training PM (or vise versa)
(3) Weight training followed by cardio
(4) HIIT

Depending on the duration and intensity, cardiovascular exercise can deplete muscle glycogen levels significantly. Supplementing with Xtend will assist in sparing muscle glycogen and muscle tissue and increase gluconeogensis. In addition to this, the citrulline-malate in Xtend will increase your performance due to its ATP boosting effects.

(1) Cardio only
If you are only doing cardio on a given day, I would treat this just as you would a weight training workout. Start sipping your Xtend 15 minutes prior to the start of your cardio (i.e. while driving to the gym). Continue sipping Xtend throughout your cardio session. Dosing will depend mainly on the duration. I would suggest taking 1 serving of Xtend per 10 minutes of cardio.

Another option would be to decrease the amount of Xtend and add some whey protein for session greater than 40 minutes. For example, you could do 3 servings of Xtend and 1 serving of Substance WPI (with the matching flavor).

(2) Cardio AM, Weight Training PM
If you perform both cardio and weight training on the same day, I would recommend dosing 3 servings of Xtend pre/during/post weight training as outlined above and supplementing with an additional 2-3 servings of Xtend during your cardio session.

(3) Weight training followed by cardio
If you perform cardio after your weight training session, I would recommend increasing your Xtend servings from 3 to 4-6 servings. Add all of the servings to a jug or water bottle and sip throughout your weight training session as usual. Whatever Xtend you did not drink during your workout is to be drunk during your cardio session.

(4) HIIT
            HIIT is an anaerobic form of cardio. While a HIIT session is usually shorter in duration then a cardiovascular session, it is much more intense. I would recommend using 1-3 servings of Xtend during the session. If you are doing sprints, I would suggest taking 1 scoop (1/2 servings) per 5 sprints.

What Supplements Can I Combine with Xtend for Enhanced Results?

The Mammalian Target of Rapamycin (mTOR) is one of the body's protein synthesis regulators. mTOR functions as an energy sensor; it is activated when ATP levels are high and blocked when ATP levels are decreased (AMPK is activated when ATP decreases, which works antagonistically to mTOR).

The main energy-consuming process in the cell is protein synthesis. When mTOR is activated (high ATP levels sensed) protein synthesis is increased and when mTOR is suppressed (low ATP levels are sensed) protein synthesis is blunted.

MTOR activation is vital for skeletal muscle hypertrophy. Interestingly, mTOR is also a nutrient sensor of amino acid availability, specifically of leucine availability. Research has shown that regulation of mTOR by ATP and amino acids act independently through separate mechanisms (Dennis et al., 2001).

It is my belief that combining supplements that increase/elevate ATP levels with BCAA will lead to an increased activation of mTOR, and therefore protein synthesis. Our goal is to keep ATP levels elevated while working out. To do so, we must supply the needed nutrients and substrates before and after the workout to keep ATP levels elevated and our bodies primed for growth.

Creatine

Creatine is used in the high-energy phosphate or ATP-PCr system to regenerate ATP. ATP, the body's main source of energy, is a molecule of adenosine (adenine + the sugar ribose) linked to three phosphate molecules by high-energy bonds. Breaking of the two outer bonds results in the release of energy.

When the most outer bond is broken, the energy is released and ADP and Pi are left behind. Creatine, which is bonded to a phosphate ion, transfers energy to the ADP and Pi molecule by breaking its own bond. This regenerates the ATP molecule, which means one now has more energy to use.

Skeletal muscle has a limited storage of creatine. Therefore supplementing with creatine increases your ability to form ATP and therefore increases the available energy for exercise (Casey et al. 1996 & 2000). More importantly to our topic on hand, by keeping ATP levels by supplementing with creatine we increase protein synthesis through mTOR activation. Creatine also has many other beneficial effects that are to numerous to address here.

Nitric Oxide (NO) product (Arginine, DiArginine-Malate, AAKG, etc)

The rate-limiting step of amino acid uptake into skeletal muscle is the transportation of the amino acids through the blood to the skeletal muscle, which is governed by blood flow (Wolfe, 2004). NO vasodilates blood vessels, thereby increasing blood flow. This increase when combined with exercises means greater blood flow and greater amino acid deliver and uptake in the working skeletal muscle. Exercise itself results in an increase in NO production, and the increased blood flow created by exercise is believed to be linked to the increase in protein synthesis post workout (Douglas et al., 2004). Xtend already has Citrulline-Malate in it, which will increase NO production, but an additional serving of arginine (i.e. 5 grams) preworkout should further enhance NO production, blood flow, and amino acid uptake.

Do I have to take Xtend on off days?

No it is not necessary to take Xtend on off days, though doing so will enhance your recovery. The most important time to take Xtend is during training.

Can I stack Xtend with VasoCharge?

Yes. We highly recommend taking 2 scoops of VasoCharge +  2 scoops of Xtend pre-workout and then sipping on 4-8 scoops of Xtend during your workout.

Can I stack Xtend with Sesamin and Dialene 4?

Yes, Xtend can be stacked with the entire Scivation product line.

Can I overdose on Xtend?

It really is not possible to overdose Xtend.

Can I take Xtend with meals?

Yes, that is perfectly fine.

Will Xtend cause me to fail a drug test for natural bodybuilding competitions?

No. Xtend contains all natural ingredients and no hormones. It will not cause you to fail a drug test.

References:

Casey, A, Constantin-Teodosiu D, Howell S, Hultman E, Greenhaff PL. (1996) Creatine ingestion favorably affects performance and muscle metabolism during maximal exercise in humans. Am J Physiol. Jul;271:E31-7.
Casey A, Greenhaff PL. (2000).Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance?Am J Clin Nutr. Aug;72(2 Suppl):607S-17S. Review.
Doi M, Yamaoka I, Fukunaga T, Nakayama M. Isoleucine, a potent plasma glucose-lowering amino acid, stimulates glucose uptake in C2C12 myotubes. Biochem Biophys Res Commun. 2003 Dec 26;312(4):1111-7.
Douglas, Borsheim, and Wolfe. "Potential Ergogenic Effects of Arginine and Creatine Supplementation" J Nutr. 2004 Oct;134(10 Suppl):2888S-2894S.

Shimomura, Y. Murakami, T.Nakai, N. Nagasaki, M. Harri, R.A. (2004). Exercise Promotes BCAA Catabolism: Effects of BCAA Supplementation on Skeletal Muscle during Exercise J. Nutri. 134: 1583S-1587S. 

Taylor WM, Halperin ML. Effect of valine on the control of fatty acid synthesis in white adipose tissue of the rat. Can J Biochem. 1975 Oct;53(10):1054-60.

Wolfe, et. al., In vivo muscle amino acid transport involves two distinct processes. Am J Physiol Endocrinol Metab. 2004 Jul;287(1):E136-41.