EFS Drink Mix

$34.99 USD

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PREMIUM ENERGY & HYDRATION MIX

Our award winning EFS mix has been redesigned to help you train and race like never before.  Backed by science and packed with 30g of carbohydrates per serving, the new EFS formula redefines fueling to help you go further, faster.

✓ Increases energy & improves performance
✓ Clinically effective dose of all 5 electrolytes to prevent cramping & dehydration
✓ Isotonic for rapid rehydration
✓  Zero Artificial Ingredients

Size
Flavor
Minus Plus
More details Right
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

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

FUELING & HYDRATION, EVOLVED

DISCOVER THE DIFFERENCE

The all-new, scientifically formulated EFS is engineered to maximize performance by delivering a precise combination of Multiple Transportable Carbohydrates (MTC’s) so you can consume more carbohydrates without GI distress.

The lightly flavored isotonic mix improves performance, enhances hydration and combats fatigue more effectively than ever before.

RACE FEARLESSLY

NEVER WORRY ABOUT CRAMPING AGAIN

CLINICALLY EFFECTIVE DOSE OF ALL 5 ELECTROLYTES.

Unlike most drink mixes, EFS delivers a clinically effective dose of all 5 electrolytes (sodium, potassium, chloride, calcium, magnesium) in the levels shown to prevent cramping, so you can train and race without worrying about cramping.

Total electrolyte content (Na, Ca, Mg, Cl, K+) in mg
Based on 1 serving (12/23)

PERFORMANCE-DRIVEN INNOVATION

ONCE YOU TRY IT, YOU'LL NEVER USE ANYTHING LESS

“The latest EFS formula is a breakthrough in fueling and hydration. With more carbs and electrolytes than competitors, you’ll finish the race as strong as you started.”

–Phil Gaimon (2x World Hillclimb Champion)

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

SCIENTIFICALLY FORMULATED FOR RAPID REHYDRATION

REPLENISHES ESSENTIAL ELECTROLYTES QUICKLY

The isotonic EFS formula combines advanced research and technology to replace the fluids and electrolytes lost during exercise faster for superior performance and sustained endurance.

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

8th Place Unbound (2024)

GO FARTHER, FASTER

FUEL FOR MORE

The scientifically validated EFS formula helps you maintain peak performance, and optimize energy levels while others struggle to keep pace.

WHY CHOOSE EFS?


EFS

OTHER DRINK MIX
Scientifically validated 2:1 glucose: fructose ratio of carbohydrates to maximize endurance and performance. Single-source carbs; prone to energy dips.
Delivers a clinically effective dose of all 5 electrolytes to prevent cramping & dehydration. Limited electrolytes, not clinically effective. Doesn't prevent cramping or dehydration.
Isotonic formula that quickly replenishes the fluids and electrolytes lost during exercise. Non-isotonic; slower fluid absorption.
No artificial flavors, sweeteners or colors. No fillers. Often contains artificial flavors, artificial sweeteners and artificial colors. May contain fillers.

PERFORMANCE BENEFITS

Delivers immediate & sustained energy-for peak performance

Prevents cramping and dehydration—delivers 1175mg of electrolytes

Ideal carbohydrate ratio-for 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.

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

"Beyond the increase in carbs/serving, I think the new flavors are the biggest advancement."
Jeffrey Rocco, MD

A SYSTEM THAT PUTS ENDURANCE FIRST

Each First Endurance product is exceptional on its own, but together they become a synergistic fueling system that allows you to train harder and race stronger than ever before.

"EFS has light flavor that’s gentle on the stomach, allowing me to fuel up as much as I need without any issues."
Vincent Bonacci

Team USA Biathlete

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 acid 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

Delivering nutrients means nothing if your body can’t sign for the package, so we sourced every ingredient for purity and bioavailability.The carbs’ low osmolality provides superior fluid absorption and reduces GI distress.

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.

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

NUTRITION FACTS



30 servings per container

Serving size one scoop (35g)


Amount per serving

Calories 120


% Daily Value•

Total Fat Og

0%

Saturated Fat Og

0%

Trans Fat Og


Cholesterol 0mg

0%

Sodium 300mg

13%

Total Carbohydrate 30g

11%

Dietary Fiber Og

0%

Total Sugars 25g


Includes 25g Added Sugars

50%

Protein Og


Vitamin D Omcg

0%

Calcium 100mg

8%

Iron 0mg

0%

Potassium 160mg

4%

Magnesium 150mg

35%

Chloride 465mg

20%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.


INGREDIENTS: Cane Sugar, Dextrose, L-Glutamine, Citric Acid, Maltodextrin, Salt, Dimagnesium Malate, Dipotassium Phosphate, Dicalcium Malate, Natural Flavor.

Q&A

Q: What makes EFS different from other hydration or fueling products?

A: EFS delivers high quality carbohydrates (30g/scoop) to keep you energized along with a clinically effective dose of all 5 electrolytes to prevent cramping and dehydration — all in a clean, easy to digest formula with no artificial flavors, colors, or stevia. It's also designed to be scalable and taste great even during long efforts.

Q: How should I mix EFS?

A: We suggest mixing 1 scoop of EFS in a small water bottle (1.5-2 scoops/large bottle) and adjusting from there, depending on desired carb/hour, sweat-rate, taste preference, body size and conditions (temp, etc..). 

Q:What are the main differences between this formula and the prior version?

A: The new EFS delivers more carbs and electrolytes (possible because of new technology), no longer contains Suntheanine (because of athlete & customer requests), or BCAA's (the latest research shows they can cause GI distress and may delay carb absorption and digestion). We also reduced the flavor and sweetness (because of athlete & customer requests).

Q: How is EFS different than EFS-PRO?

 A: Though EFS is itself a step above the competition, EFS-PRO supports the most demanding efforts in the most extreme conditions by providing 2x more carbs and more electrolytes/serving. 

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 glycogen and electrolyte levels before an event or race.

 Q: Is EFS gluten free?

A: Yes, EFS and EFS-PRO are both gluten free.

 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. In other words, if you are a smaller person and normally consume a somewhat reduced amount, you will still get the same benefits.

 Q: How much EFS should I use during my training and racing?

 A: For best results, have one serving 30 minutes before exercise & use as needed during exercise. Additional calories and electrolytes can be added with Liquid Shots.

Q: Is EFS vegan friendly?
A: Yes.

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

A: The glucose: fructose ratio in the EFS formula is  2:1 Glc:Fru.

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 of the free form amino acid glutamine per serving which is the equivalent of 9g whey protein. Protein naturally contains glutamine.

Clinical evidence supporting the use of 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 exercise, they don’t taste very good during exercise, and they 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 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 and dehydration problems?

A: Yes, cramping stems from electrolyte imbalance, electrolyte depletion and/or dehydration. EFS provides a clinically-effective dose (of all 5 key electrolytes) to prevent cramping and dehydration. The combination of all five electrolytes delivers a potent 1175 mg 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 not necessary with EFS.

Overall rating: 4.87013 / 5 from 154 reviews.

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Review highlights

Reviews

Great

"No GI distress with this. When used I seem to be able to fuel adequately for my rides. Great flavors that help break the sweetness up, big fan of sour watermelon. However, I find on long hot rides, the flavors can get a little strong after a few hours and find myself just wanting water."

— CB (5/5)

Outstanding product with great flavors

"Love this product and use it for all my rides. The flavor is great and I have stopped cramping on long rides since switching to EFS."

— Eric K. (5/5)

Exactly what I need

"Tastes good and doesn't clump. Good mix of all the electrolytes. My new fave drink."

— Nathan T. (5/5)

No upset stomach and great power

"I love this stuff. I accidentally forgot my EFS when I left it on the counter at home before flying out of state with my bike last fall. I used a competitors product purchased at a bike shop and got an upset stomach. EFS is engineered well and it works extremely well and is easy to digest."

— Scott M. (5/5)

"Best products to be a fast cyclist"

— Scott (5/5)

Great tasting quality product

"I've been using this product for about 6 months to help me stay fueled through my training. I am a CrossFit athlete training multiple workouts a day, this keeps my glucose stores fueled and keeps me hydrated, really happy with this."

— Dan (5/5)

Best taste ever!

"I mix this with the High Carb, 1:1 ratio and the results have been awesome! Started training and only using FE and its been going really really good. Not a single cramp, even on longer 60 mile XC rides."

— Gus E. (5/5)

EFS for the win!

"I've been using EFS to fuel my runs and OCR races, and I love it. It mixes well, is flavored just right (not too strong or overpowering like many are), and it provides enough carbs and electrolytes for an hour+ grueling OCR race. So glad I found First Endurance!"

— Chris M. (5/5)

EFS got me from LA to Boso

"Last year I and 24 others biked from LA to Boston. EFS helped get me through without cramping, feeling great the next day. I swear by the stuff and won’t ride without EFS in my bottled."

— Rich B. (5/5)

EFS is something far above any standard

"Runs have gotten much easier … less fatigue during time on my feet especially . Beats the lactic burn especially because I preload with EFS … tastes so good , no gut bombs or issues period . Feels like lubrication for your muscles honestly and perfect fuel for endurance . Just finished a 25k preloaded on EFS …… ran a 9:15 pace , finished in 2:25:38 …. i honestly felt so good the entire pace and when I crossed the finish line I couldn’t believe that was my last loop . . !! Thank you First Endurance 🙏"

— Gregg G. (5/5)

Q&A