EFS Hydration Drink

$34.99 USD

PREMIUM HYDRATION MIX

Isotonic formula that provides everything you need to maximize endurance and performance during exercise. With the ideal carbohydrate sources, industry-leading cramp prevention, and key ingredients that support optimal hydration, EFS refuels working muscles faster than ever before.

✓ Provides immediate & sustained fuel
✓ Industry-leading cramp prevention
✓Contains patented Suntheanine® for mental toughness

Size
Flavor
Minus Plus
More details Right
Endurance & Recovery

Energy Production



BRANCHED CHAIN AMINO ACIDS (BCAAS)

Promotes long-duration exercise performance and recovery with less fatigue. Triggers upregulation of the TCA cycle for energy production. Slows the degradation of L-glutamine. Replenishes rapidly decreasing BCAA levels during exercise.

Natural Sources Dietary Protein Sources (Especially Whey Protein)

Forms Instaminos® L-Leucine, L-Isoleucine, L-Valine (2:1:1 ratio)

Supplier Compound Solutions

Relevant Literature

Cell Function

Muscle Contraction

Cramp Prevention

CALCIUM

Required for muscle contraction. Triggers many cellular functions during exercise. Usually not present in water, sports drinks, multivitamins or other supplements used by exercisers.

Natural Sources Formed during digestion with soluble calcium ions in presence of malic acid. Small amounts are in cells throughout food sources.

Forms Dicalcium Malate Dihydroxide

Supplier Balchem® Albion® DimaCal®

Relevant Literature

Sodium Utilization

Cramp Prevention



CHLORIDE

Necessary to reap benefits of sodium. Decreases gastric intolerance from high sodium intakes, not seen with high intakes of chloride-free sodium salts.

Natural Sources N/A

Forms Evaporated Salt

Supplier Cargill

Relevant Literature

Energy Production





CITRIC ACID

Major metabolite for aerobic respiration (energy production). Enhances flavors and palatability. Regulates pH (buffering acidity). Helps mixtures of nutrients mix, taste, dissolve, and suspend better.

Natural Sources Fruits and Juices

Forms Citric Acid Anhydrous Powder (2-Hydroxypropane-1,2,3-tricarboxylic Acid)

Supplier Cargill

Relevant Literature

Energy Production

Endurance Performance & Recovery

Brain Function

GLUCOSE

Preferred, primary fuel for cellular energy production (ATP) and endurance exercise performance. Primary precursor for muscle and liver glycogen synthesis. Aids exercise recovery. Affects metabolic pathways such as insulin release and regulating fat synthesis. Crucial for brain function.

Natural Sources Non-Fiber Carbohydrates, Sucrose, Galactose

Forms Dextrose, D-Glucopyranose, Blood Sugar; Glc

Supplier Ingredion

Relevant Literature

Energy Production

Endurance Performance & Recovery

Brain Function

MALTODEXTRIN

Preferred, primary fuel for cellular energy production (ATP) and endurance exercise performance. Primary precursor for muscle and liver glycogen synthesis. Aids exercise recovery. Affects metabolic pathways, insulin release, and fat synthesis.

Natural Sources Starches in Grains, Corn, Vegetables, and Flour

Forms Glucose Polymers with Chain Length 2-40+ Glucose Units (Maltodextrin, Dextrin, Polydextrose, Modified Starch, Hydrolyzed Amylose)

Supplier Chicago Sweeteners, Ingredion

Relevant Literature

Cellular Hydration

Exercise Recovery

Immune Support

Glutamine

The most plentiful amino acid in your body, muscles, and bloodstream. Major energy source for immune, intestinal, and muscle cells. Aids cellular hydration. Supports exercise recovery.

Natural Sources Uncooked Proteins

Forms L-Glutamine

Supplier Prinova

Relevant Literature

Cramp Prevention





MAGNESIUM

Addresses common athlete deficiency. Prevents cramps. Chelate form reduces GI distress.

Natural Sources Formed During Digestion with Soluble Magnesium Ions in Presence of Malic Acid

Forms Dimagnesiumhydroxymalate

Supplier Balchem®, Albion®

Relevant Literature

Energy Production





MALATES & MALIC ACID

Major metabolite for energy production via aerobic respiration. Adds sour, tart flavor and buffers acidity. Chelates calcium and magnesium for better uptake and GI tolerability.

Natural Sources Whole Foods, Fruits and Vegetables

Forms DL-Malic Acid

Supplier Tate & Lyle

Relevant Literature

Cramp Prevention

Balances Electrolytes

Nervous System Activity

POTASSIUM

Regulates muscle contraction and nervous system activity. Addresses deficiency suffered by 95% of the US population. Balances electrolyte levels during exercise.

Natural Sources Fruits and Vegetables

Forms Dipotassium Phosphate Food Grade

Supplier Budenheim

Relevant Literature

Cramp Prevention

Heat Tolerance



SODIUM

Maintains tolerability to heat. Prevents sweat loss of sodium. Maintains plasma volume. Improves exercise recovery. Decreases urine output. Increases benefits with co-ingestion of other electrolytes. More effective than other sodium salts. 

Natural Sources Salt

Forms Evaporated Salt

Supplier Cargill, United Salt Corporation, Westco

Relevant Literature

Encourages Intake





STEVIA EXTRACT (Stevia, Stevia rebaudia (leaf))

Natural sweetener. Encourages intake. Reduces amount of sweetener required. Does not affect blood glucose or insulin levels.

Natural Sources Stevia Leaves (Stevia Rebaudiensis)

Forms Stevia Rebaudioside Extracts

Supplier Proprietary

Relevant Literature

Energy Production

Endurance Performance & Recovery



SUCROSE

Provides sufficient fructose to activate GLUT5 translocation, increasing carbohydrate absorption/utilization during exercise. Less gastrointestinal intolerance than pure fructose. Aids exercise recovery. Improves flavor.

Natural Sources Table Sugar, Dates

Forms Alpha-D-Glucopyranosyl Beta-D-Fructofuranoside, Glc:Fru

Supplier The Amalgamated Sugar Company, LLC

Relevant Literature

Cognitive Performance

Immune Support



THEANINE

Supports the brain and immune system. Balances excitatory and inhibitory neurotransmitters. Maintains calm, relaxed, but alert, focused mental states. With caffeine, improves attention and focus with less overexcitation. Produces better sleep.

Natural Sources Green Tea Leaves

Forms Suntheanine® L-Theanine

Supplier Taiyo Kagaku Co., Ltd. (Taiyo International) via NutriScience Innovations

Relevant Literature

The Ideal Carbohydrates

The latest research shows you can almost double the amount of carbohydrates that can be absorbed without GI distress when fueling with Multiple Transportable Carbohydrates (MTC’s) in specific ratios. The key is to consume specific carbohydrates in the right ratios.

EFS was engineered to maximize carbohydrate utilization by delivering a precise combination of MTC's, glucose and sucrose for next-level endurance you’ll notice the first time you use it.

"When you nail your fueling it's pretty remarkable to see that you can actually get stronger as the race unfolds."
Hannah Otto

Leadville 100 Champion (2022)

INDUSTRY-LEADING ELECTROLYTE LEVELS TO PREVENT CRAMPING

We know how frustrating it is to have your day wrecked because you’re seized up with debilitating muscle cramps. It’s the number one issue most athletes face. That’s why we engineered EFS.

Unlike most hydration mixes, EFS delivers a clinically effective dose of all 5 electrolytes (sodium, potassium, chloride, calcium, magnesium) in the levels shown to prevent cramping.

A NEW WAY OF THINKING

“The latest EFS formula is a breakthrough in sports hydration. With more electrolytes than competitors and ingredients to improve mental focus, you’ll finish the race as strong as you started.”

–Phil Gaimon (2x World Hillclimb Champion)

PERFORMANCE REDEFINED

We spared no expense upgrading the EFS drink mix, investing in the latest research-driven innovation and technology. The isotonic formula delivers complete nutrition that supports physical and mental performance, redefining the limits of endurance nutrition so you can redefine your limits of endurance.

Pro Tip: For best results have a serving of EFS 30 minutes prior to training and racing.

PATENTED TECHNOLOGY

The brain plays an essential role in endurance and performance. Mental toughness and presence of mind are equally as important as fitness. You have to be able to suffer and handle stress when your body is begging you to stop.

That’s why the reimagined EFS includes Suntheanine ®, a patented innovation that gives you the mental toughness you need to push further and find a gear you didn’t know you had.

Suntheanine® is protected by over 40 U.S. and international patents for its various physiological efficacies and L-isomer specific production processes.

FUEL FOR THE FINALE

FINISH STRONGER

To keep your performance going after two hours of exercise, recent research shows BCAAs taken during exercise – not before or after – keep the flow of fuel sources from carbs and fats mobilized and upsized when you need them the most.The final sprint, the push to the summit, grinding out the last interval - BCAAs are critical when you’re on the limit but there’s still more work to do. In EFS, BCAAs unlock a final emergency fuel source when all other options – and all of your competitors – are exhausted.

"The new EFS drink mix tastes great, helps keep you focused during long and hard training sessions, and fuels the body properly."
Matt Hanson

5x IRONMAN / 5x 70.3 Champion / Holds the record for the fastest full-distance IRONMAN (7:39:25)

PERFORMANCE BENEFITS

Suntheanine® boosts mental toughness to help you push through suffering

Prevents cramping and dehydration—delivers 1160mg of electrolytes

Carbs from multiple sources provide immediate and sustained fuel

7% osmolality ensures bioavailability and reduces GI distress

Citric and malic acids promote oxygen uptake and energy production

New taste profile eliminates the flavor vs function compromise

NO MORE GUESSWORK

EFS provides everything you need to maximize endurance and performance. Our industry-leading electrolyte levels help you stay hydrated and avoid cramping.

With the latest amino acid technology and ideal carbohydrate sources, EFS refuels working muscles faster than ever. Plus, the new flavor technology eliminates the formula over flavor compromise.

With EFS, you can train and race with confidence knowing you don’t have to worry about gaps in your nutrition.

"Beyond the importance of Suntheanine, I think the new flavors are the biggest advancement."
Jeffrey Rocco, MD

A SYSTEM THAT PUTS ENDURANCE FIRST

EFS is for use during exercise to prevent cramps, maintain fuel levels, and support mental toughness when it’s needed most. It can be supplemented with Liquid Shots before and during an event, and Ultragen helps consolidate gains during recovery between sessions. 

Regardless of your training load, a daily dose of our MultiV and Optygen lines help you lay a foundation to achieve your goals.

"On-the-bike taste was great. I felt amazing on the bike today! I had a PR on the top half of the climb. Surprised by this, because I had skied hard the day before."
Doug Davis

Cat I Cyclist

RESEARCH

BIOAVAILABILITY IS THE BEST ABILITY
From the carbohydrates (osmotically balanced with your body in a 7% solution) to the electrolytes (20-100% better absorption rates), every ingredient in EFS is selected and portioned for faster and easier absorption without GI distress.

The inclusion of citric and malic acids also encourages oxygen uptake and production of ATP (the body’s energy source), helping your cells use the fuel once it’s delivered.

PREMIUM INGREDIENTS FOR PURITY AND PURPOSE

We prioritize purity by using only Suntheanine, the original and cleanest L-theanine, and free-form amino acids, which have a purity level of 99-100%.

We also omit ingredients with no value—even the ubiquitous vitamin C, which features in virtually every other mix despite research that shows it reduces endurance when taken during exercise. EFS still provides immune system support courtesy of theanine, just without impacting performance.

NO RESPECT FOR THE STATUS QUO

Our approach to product design eschews unexamined ingredients, traditional processes, and trendy minimalism in favor of research-based innovation, premium ingredient sourcing, and the uncompromising expectations of elite athletes. We’re always ready to show our work and support our products with the scientific literature that informs our design choices, but we also know what virtually every athlete and publication using or reviewing our products learns firsthand: First Endurance products speak for themselves, and you can feel the difference right away.

Download Research Packet

SUPPLEMENT FACTS



Supplement Facts
Serving Size: 1 scoop (32 g)
Servings per Container: 30
Amount Per Serving %DV
Calories-110 Calories from fat-0
Total Carbohydrate 26 g 9%
Sugars 16 g **
Calcium (as DiCalcium Malate) 100 mg 8%
Magnesium (DiMagnesium Malate) 150 mg 36%
Chloride (as sodium chloride) 450 mg 20%
Sodium (as sodium chloride) 300 mg 13%
Potassium (as di-potassium phosphate) 160 mg 3%
L-Glutamine 1750 mg *
Branched Chain Amino Acids (L-Leucine, L-Isoleucine, L-Valine) 250 mg *
L-Theanine 50 mg *
*Daily Value Not Established
**Percent Daily Values are based on a 2,000 calorie diet.
Other ingredients: Sucrose, Maltodextrin, Glucose, Citric Acid, Natural Flavor, Stevia Extract.

Q&A

Q: How is EFS different than EFS-PRO?

 A: Compared to EFS, EFS-PRO has a more premium ingredients list, delivers more carbs and electrolytes, and includes PharmaGABA® for added mental toughness support. Though EFS is itself a step above the competition, EFS-PRO supports the most demanding efforts in the most extreme conditions by providing even more fuel and cramp prevention while doubling down on First Endurance’s revolutionary approach to supporting your brain like it’s a key muscle for endurance athletics. 

Q: Are there other benefits to drinking EFS or EFS-PRO, besides for training and racing?

A: Absolutely. EFS and EFS-PRO can be used to top off electrolytes and help you calm down so you can get a good night’s sleep the night before (or two nights before) an event or race. When you’ve invested an entire season’s prep in peaking for a specific day, the calming effects of EFS or EFS-PRO can help ensure restless nights leading up to that day don’t undercut your form. 

 Q: Do EFS or EFS-PRO have any artificial flavors or colors?

A: No, but it tastes so good you’d be forgiven for thinking we were cheating.

 Q: Do I need to take a full serving of EFS or EFS-PRO to get a benefit? 

A: No. A higher concentration increases calories and electrolytes. While our recommended serving concentration is designed to maximize theanine’s effects in a steady dose, ingesting reduced amounts will still produce a proportionally scaled effect in terms of promoting calm focus. In other words, if you are a smaller person and normally consume a somewhat reduced amount, you will still get the same benefits.

 Q: Do EFS or EFS-PRO have any stimulants in it?

No. In fact, it does the opposite, calming you down and maintaining a cool, collected approach to whatever you’re doing, whether that’s racing, training, or resting up the night before an event.

 Q: Can I use EFS and EFS-PRO with caffeine?

Yes. The calming effects of EFS and EFS-PRO affect you according to the baseline for caffeine consumption that you’ve established through your daily caffeine habit—err, intake. Keep drinking tea or coffee as usual. 

 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. Athletes should consume one serving for every 30 minutes of intense exercise. Adjustments should be made based on body weight, training state, heat, individual sweat rates and preference. Use one serving for every 30 minutes as a starting point and adjust as necessary from there.  Additional calories and electrolytes can be added with Liquid Shots.

 Q: How should I mix EFS?

A: USE DIRECTIONS
SMALL SERVING: Mix 1 scoop with 21-22oz of water

LARGE SERVING: Mix 1 ¼ scoop with 24-26oz of water

BEFORE: Consume 1 bottle 30 minutes before exercise.

DURING: Consume EFS as needed.

TIP: For additional calories and electrolytes, double the concentration or supplement
with Liquid Shot.

Q: Is EFS vegan friendly?
A: Yes.

Q: Is EFS gluten-free?
A: Yes.

Q: What's the glucose:frucose ratio in the formula?

A: The glucose: fructose ratio in the EFS formula is  6:1 Glc:Fru.

Q: Is there any way to get too much Theanine from EFS or EFS-PRO?

A: Only if you macro-dose (200mg or more in a single or repeated shot). Even if theanine is administered in a single macro-dose, the effect is just a too-calm calm that fades as the theanine leaves your body—Nothing serious or harmful. Click here to learn more about dosing and uptake. Since our EFS or EFS-PRO serving is limited to a gradually administered 80g every hour, you won’t hit that dose of theanine, even with continued use as directed. That’s because theanine is water-soluble, it metabolizes fast and doesn’t accumulate . Once ingested, it’s half gone after 60-90 minutes, and it’s gone completely in 24 hours.  

 Q: Does EFS or EFS-PRO help me hydrate better than water?

A: We won’t name them, but there’s a growing list of competitors in the sports hydration game making the claim that their product hydrates better or faster than water alone. This is a so-what claim predicated on evidence that not only doesn’t apply to endurance athletics, but actually hampers performance during long-term endurance events. For their rationale and claims support these companies cite WHO and other medical guidelines for treating serious dehydration in disease and severe exposure conditions, not the sports nutrition guidelines for healthy athletes in endurance competitions. Also important is the need for more fuel, and these drinks fall short in the fuel department. Check out Dr. Bucci’s extended consideration of these claims here.

 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.

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 exerciseProteins don’t taste very good during exerciseProteins can reduce the glycemic index of a drink, further reducing its ability to be quickly absorbedThere is considerably more evidence supporting free form amino acids than complete protein

 Q: Are EFS and EFS-PRO safe for kids?

Yes. Just make sure they pay it back during their turns at the front. 

 Q: I am prone to cramping during longer training and racing. Will EFS help me with cramping problems?

A: Nutritionally, cramping stems from electrolyte imbalance, electrolyte depletion and/or dehydration. EFS provides the most potent electrolyte profile available. The combination of all five electrolytes delivers a potent 1160mg per serving, helping to prevent cramping. The 300mg 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.

 Q: How should I use EFS/EFS-PRO for races or training that lasts more than three hours?

A: New research suggests athletes can ingest more and more carbs per hour. For detailed information, check out this blog.