Skip to main content
Bookmark and Share
Client Login
Global Shipping Policies
Site Map
ProLine Blog
Link To Us
Product Search 
Client Login 
Email Address
Your Password
Forgot your password?
click here
Create an account
click here to create an account.

First Endurance EFS-PRO Drink Mix 2.21 lbs. (EFS-PRO)

back add to cart
add to cart

EFS-PRO Professional Strength Endurance & Hydration Mix

The new EFS-PRO drink mix prototype contains a special carbohydrate source that has a significantly lower osmolality than any other carbohydrate available. 23 servings/container

  •  Developed to Meet the Requirements of Professional Athletes
  •  Designed to get absorbed quickly
  •  Delivers 1400mg of Essential Electrolytes to Prevent Cramping

Professional Strength Endurance & Hydration mix
The new EFS-Pro drink mix is an ultra low osmolality, state-of-the-art endurance and hydration formulation that’s engineered with the latest innovations and technology to meet the unparalleled requirements of professional athletes. EFS-Pro delivers higher levels of calories, electrolytes and other essential nutrients than other drinks without causing GI distress, even in the most extreme conditions. Plus, it’s designed to taste like flavored water so multiple bottles can be consumed easily without the dreaded ‘sweetness fatique.’ EFS-Pro features a proprietary blend of carbohydrates that has unique benefits for endurance. The primary carbohydrate is a low osmolality amylopectin multi-branched cyclic dextrin that’s 100% soluble in water. This means EFS-Pro can be mixed at stronger concentrations than other drinks and still be absorbed quickly and easily.

EFS-Pro utilizes ‘Optimal Absorption Technology’ to shuttle more water, electrolytes and other essential nutrients through the digestive system efficiently without the negative side effects of GI distress, cramping or dehydration. EFS-Pro is also fortified with sodium citrate which is clinically proven to reduce stomach acidity and improve absorption. These technological advancements work synergistically meet the unique hydration and fueling requirements of elite athletes so they can push the limits of endurance in ultra-long races, extreme heat and other difficult conditions.

FUELING TIP: We designed this formula to be mixed at varying strengths to suit your requirements. Each scoop is 40 calories. It can be used as a hydration drink at 80 calories in 12oz of water or a high-calorie formula at 120 or 160 calories in 12 ounces of water

It’s Not Your Daddy’s Endurance Drink


EFS-PRO utilizes a proprietary ‘Optimal Absorption Technology’ to shuttle water, electrolytes and other essential nutrients through the digestive system more efficiently than ever before so you don’t have to worry about all the negative symptoms of GI distress. This is of the utmost importance because when endurance athletes need the benefits of their drink mix the most (when at or above lactic threshold) is when the conditions are the worst for essential gastric emptying.

‘Optimal Absorption Technology’ contains these key ingredients because they’re shown to improve endurance and performance while exercising:

  • L-Alanyl L-Glutamine: EFS-PRO contains L-Alanyl L-Glutamine because it’s clinically proven to significantly improve absorption of water and electrolytes in humans under exercise stress and mild dehydration and improve endurance performance. This special dipeptide amino acid is a highly-soluble, water-stable source of glutamine that has a number of unique benefits for endurance athletes. Like L-Glutamine, this dipeptide plays a role in the supply of energy, promotes protein synthesis, heals wounds, promotes a healthy intestinal tract and also stimulates immune function. The alanine component of L-Alanyl L-Glutamine helps stimulate gluconeogenesis (the generation of glucose through non-carbohydrate sources). Clinical studies on L-Alanyl L-Glutamine have shown it improves plasma glutamine by 26% over a basic L-Glutamine source. In a study done in the Journal of the International Society of Sports Nutrition, L-Alanyl L-Glutamine and water were administered to college students with induced dehydration of -2.5% while a second group used only water. The group using L-Alanyl L-Glutamine showed a dramatic improvement in their hydration status and well as their serum sodium levels. This group also improved their performance in a treadmill exercise significantly.

    Hoffman JR, et al. Examination of the efficacy of acute L-Alanyl L-Glutamine ingestion during hydration stress in endurance exercise. Journal of the International Society of Sports Nutrition. 7:8, 2010
  • Cyclic cluster dextrin: EFS-PRO delivers a proprietary blend of carbohydrate sources that each offer unique benefits for endurance athletes. These sources work synergistically to achieve optimal performance through varying channels of absorption. The primary carbohydrate used in EFS-PRO is an amylopectin multi-branched cyclic dextrin that’s 100% soluble in water and won’t clump or thicken when mixed, which is a good indication of how it get’s absorbed in the stomach. It’s a high-glycemic carbohydrate that has little effect on insulin and does not inhibit fat oxidation. This means athletes are able to sustain hard efforts through the increased use of fats, which allows them to spare essential glycogen. At 150 mOsm, cyclic dextrin is the lowest-osmolality carbohydrate source available and has been clinically proven to have the fastest gastric emptying time of any carbohydrate. This low-osmolality and superior gastric emptying times means athletes can be assured what they drink goes directly to working muscles immediately. This also means EFS-PRO can be mixed at stronger concentrations and still be absorbed properly. In a published clinical study done on competitive swimmers, those using cyclic cluster dextrin significantly improved swimming time over swimmers using other carbohydrate sources.

    Int J of Sports Med, 26: 314-319, 2005
    Biosci Biotechnol Biochem, 63: 2045-2052 , 1999
  • Sodium Citrate: Sodium citrate is absorbed and metabolized into sodium bicarbonate which causes an alkaline solution that reduces stomach acidity and improves absorption. Alkalizing agents have also been shown to improve performance in high intensity exercise. Sodium citrate has been clinically shown to have the best absorption rates among various sodium sources. A clinical study done on Sodium Citrate showed that, when consumed prior to high-intensity exercise, it reduced blood pH and oxygen debt in healthy males exercising on a cycle ergometer.

    Jain P,. et al. Effect of sodium citrate ingestion on oxygen debt & exercise endurance during supramaximal exercise. Indian J of Med Res. Jul; 118: 42-6, 2003.


add to cart add to wishlist

Q: What is EFS-PRO?
A: EFS-PRO is a new energy drink that provides endurance athletes with the nutrients they need to fuel working muscles and increase endurance during exercise. The EFS formula utilizes the latest clinical research on endurance nutrition and input from some of the best endurance athletes in the world.

Q: Why doesn't EFS-PRO contain Vitamin C?
A: EFS-PRO doesn't contain Vitamin C because the latest research shows that Vitamin C can have a negative effect on endurance and performance when consumed during exercise.

Q: What electrolyte can we find in the new EFS-Pro?
A: There is 500mg of sodium per serving in the new EFS-Pro drink (EFS has 300mg). This represents the highest sodium content in any electrolyte drink on the market. The EFS-PRO formula now offers over 1,500mg of electrolytes coming from all 5 electrolytes, per serving.

Furthermore these superior minerals also offer a buffering of stomach acids. DiCalcium and DiMagnesium malate lower stomach acids significantly helping to reduce the unwanted gastric distress that can be associated with other minerals.

Q: Are there any changes to the amino acids?
A: The amino acids in the EFS-Pro drinks are AjiPure amino acids, the purest, most- bioavailable source of free-form amino acids available. AjiPure amino acids have purity levels of 99%-100%. This results in faster and more complete absorption.

Q: What is L-Alanyl L-Glutamine?
A: The EFS-Pro is also fortified with L-Alanyl L-Glutamine which is a highly soluble water stable source of glutamine with some very unique features. This amino acid has been clinically proven to significantly improve the absorption of water and electrolytes in the intestinal tract.

Q: What is malic acid used for in the EFS-Pro drinks? Why is this important?
A: The new EFS-PRO drink contains 700mg of malic acid. Malic acid stimulates oxygen consumption by increasing mitochondrial uptake, improving mitochondrial respiration and increasing energy production. Malic acid is essential in the formation of ATP, the body's energy source. Malic acid allows the body to make ATP more efficiently, even under low oxygen, or hypoxic conditions.

During anaerobic conditions, malic acid has an ability to remove the accumulation of reducing equivalents. Human studies have shown that after endurance training, athletes' muscles were characterized by a 50% increase in the malate-aspartate redox shuttle enzymes.

Q: How is the flavor?
A: The new EFS-PRO formula went through extensive flavor testing in the most demanding races in the world. We used this extensive feedback to create a flavor profile that mimics flavored water. With practically no sweetness this formula is ideal for those long, hot workouts where sweet drinks simply do not cut it. All formula uses 100% natural flavors and contains NO color. This allows athletes to use EFS not having to worry about staining water bottles.

Q: I've heard that there are benefits to having protein during exercise. Why doesn't EFS contain protein?
A: EFS contains 2g free form amino acids per serving which is the equivalent in BCAA and glutamine profile to 9g whey protein. Protein naturally contains BCAAs and glutamine. Clinical evidence supporting the use of BCAAs and glutamine during exercise dates back to 1991. These clinical studies clearly indicate supplementing with as little as 1g free form amino acids improved performance, reduced post-exercise muscle damage, improved muscle glycogen resynthesis, reduced central fatigue and improved rate of perceived exertion. These are the same claims made by the most recent protein study and clearly support a mechanism for improved performance.

The First Endurance Research Board sides with the abundance of clinical studies supporting improved endurance performance while supplementing with amino acids during exercise. In addition to the clinical support, other factors lead to a decision to use these free form amino acids over complete proteins.

  • Proteins are more difficult to digest than amino acids during exercise

  • Proteins don't taste very good during exercise

  • Proteins can reduce the glycemic index of a drink, further reducing its ability to be quickly absorbed

  • There is considerably more evidence supporting free form amino acids than complete proteins

Q: What are the benefits of using EFS-PRO during exercise?
A: The benefits of EFS are:

  • Supplying fast and sustained energy for muscles

  • Improved fluid absorption

  • Reduced cramping and dehydration

  • Improved performance

  • Easy to digest and absorb

  • Improved glycogen resynthesis

  • Delayed central (mental) fatigue

  • Replenishment of electrolyte loss

Q: How does it taste?
A: EFS-Pro literally tastes like cucumber water.

Q: How much EFS should I use during my training and racing?
A: Clinical research shows that a 6-8% solution delivering between 45-60g carbohydrates, >1000mg amino acids, 400-600mg sodium and equivalent balance in all electrolytes should be taken every hour during exercise. EFS is designed to maximize all these levels. Athletes should consume one serving for every 30 minutes of intense exercise. Adjustments should be made based on body weight, training state, individual sweat rates and preference. Use one serving for every 30 minutes as a starting point and adjust as necessary from there.

Q: What types of athletes should be taking EFS-PRO?
A: Long and short distance athletes can use EFS-PRO effectively.

1) Athletes which experience cramping from strenuous exercise.

2) All athletes who demand rapid fluid absorption in order to stay hydrated.

3) Athletes who want all the benefits of protein without the heavy/chalky consistency of protein drinks. Essentially any athlete exercising for one hour or more will benefit from the use of EFS in their training and racing.

Q: Should I use EFS-PRO even when it's cold, like during XC ski races?
A: Cold weather sports still put a considerable fluid and electrolyte demand on the athlete. EFS works just as well in the cold as is the heat. Through experience we have found the EFS Liquid shot to be preferred during cold weather training.

Q: Should I use EFS-PRO in short races?
A: Short races generally don't put a heavy demand on your glycogen carbohydrate stores, given that you are well nourished prior to the start of the race. During a short race athletes can be slowed significantly from cramping and electrolyte imbalance. A serving of EFS can be used 15-30 minutes prior to a short race (<1 hour) to assure adequate carbohydrates and electrolytes are available for the intense effort. Short race is defined as one lasting less than one hour.

Q: Should I use EFS-PRO in long races?
A: During long races (3+ hours) considerable stress is put on an athlete's body: 1) glycogen (energy) stores are depleted; 2) electrolytes are depleted; and 3) amino acids are depleted.

1) EFS-PRO replenishes glycogen by using a mix of high glycemic carbohydrates including both simple and complex sugars. This easy to digest mix is rapidly absorbed and delivers fast and long term energy. EFS-PRO contains a powerful absorption technology blend of cluster dextrins and L-Alanyl L-Glutamine that further drives fluid and electrolytes from the gut to the working muscles.

2) EFS-PRO provides the most potent electrolyte profile available. The combination of all five electrolytes delivers a potent 1500mg per serving, helping to prevent cramping. The 500mg sodium per serving also aids in maximum fluid absorption so you stay hydrated throughout your training and racing. Supplementing with additional salt tabs, electrolyte tabs, or salty snacks is no longer needed when using EFS-PRO.

4) 2000mg of Amino Acids offers the same BCAA and glutamine levels as 9g whey protein. These amino acids have clinically shown to improve performance, reduce post-exercise muscle damage, improve muscle glycogen resynthesis, reduce central fatigue and improve rate of perceived exertion.

Customers who bought this item also bought:

VO2-BOOST is a powerful endurance enhancer clinically proven to dramatically improve athletic performance.

The patent-pending VO2-BOOST formula has been developed through extensive research and has been shown in independent laboratory testing to promote speed, endurance and strength in University athletes in one month! You will move faster, feel stronger and have more endurance with VO2-BOOST than anything else on the market...Guaranteed.

Reg. Price:
Sale Price:

Optimize your performance with the World's First All Natural Energy and Recovery Drink. TriFuel™ is different than all the other bounce you off the wall energy drinks. EnduraFuel is a complete energy system of amino acids, electrolytes and carbohydrates.


Customer Reviews
There are no reviews yet. create your own review

Resources for Today's Endurance Athletes ®

Copyright © 2023 ProLine Sports Nutrition, Inc. ®

Email Customer Care

Disclaimer: While we work to ensure that product information is correct, on occasion manufacturers may alter their ingredient lists. Actual product packaging and materials may contain more and/or different information than that shown on this website. We recommend that you do not solely rely on the information presented and that you always read labels, warnings, and directions before using or consuming a product. For additional information about a product, please contact the manufacturer. Content on this Website is for reference purposes and is not intended to substitute for advice given by a physician, pharmacist, or other licensed health-care professional. You should not use this information as self-diagnosis or for treating a health problem or disease. Contact your health-care provider immediately if you suspect that you have a medical problem. Information and statements regarding dietary supplements have not been evaluated by the Food and Drug Administration and are not intended to diagnose, treat, cure, or prevent any disease or health condition. ProLine Sports Nutrition, Inc. ®

Item Added To Cart