EFS Electrolyte Powder Drink

EFS Electrolyte Powder Drink

Prevents Cramping & Dehydration

With the highest electrolyte content available, EFS drink mix provides everything you need to maximize endurance and performance during exercise.

Endurance Drink Mix
Prevents Cramping & Dehydration
Contains Malic Acid

As low as $24.95

In stock

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More Electrolytes Than Any Other Drink

We hydrated with the new EFS formula exclusively all spring during ski and bike adventures and can say that you will notice the difference." 

We Recommend Together

Detailed Information

EFS drink mix provides everything you need to maximize endurance and performance during exercise. You’ll notice the difference right away too. With the latest amino acid technology, superior mineral bioavailability and the addition of Malic Acid, EFS drinks refuel working muscles faster than ever before. Plus they taste great, not chalky or overpoweringly sweet.

With the highest electrolyte content available (1160mg of all 5 electrolytes/serving), there’s no need to carry those extra electrolyte pills or add anything else. You can train and race with confidence knowing you don't have to worry about cramping or dehydration. Times have changed.


  1. EFS saved my ride Review by Pat

    In June, I was pushing to do a century ride in 5 hours. But lack of hydration and electrolytes shut that down real quick at mile 52. Luckily the rest area had EFS which I promptly drank 3 water bottles loaded with Grape EFS. My leg cramps were so bad that I couldn't walk and my riding buddy got the "magic potion" otherwise I would have had to quit. Because of EFS, I was able to continue the ride. Thank you 1st Endurance, I am so grateful for your Product (Posted on 9/18/2017)

  2. Best on market for all around performance. Review by William

    Been using EFS for over 7 years. Tired others along the way, but none have ever met the performance of EFS. The EFS product information is accurate and consistent, and other suppliers have not met this standard. (Posted on 11/1/2016)

  3. Works Amazing Review by Johnny Meyerle

    This stuff really works. I use it before and during my rides and races. It always gives me that extra boost to beat and crush my opponents! (Posted on 10/18/2016)

  4. Mind blowing Review by Paul

    I have always had some cramping after 5-6 hours on the bike. I recently did a 305 mile ride. About half of it was in very hot humid conditions. No muscle cramps at all! (Posted on 9/12/2016)

  5. Perfect for ultra running Review by Richard

    I got turned on to First Endurance from a bud who was an ultra endurance mt biker. In my first 50k run, I exclusively used EFS in the water bottle and EFS shots for nutrition. I had no cramping or other issues. As soon as I finished, I slugged down a bottle of Ultragen. I was less sore after that trail 50k than after my first road marathon the year before (without First Endurance). EFS is in every bottle or reservoir for every run. (Posted on 7/1/2016)

  6. Works for me when I go long Review by William

    Works for me when I go long (Posted on 12/21/2015)

  7. Cramp Crushing and Easy to Stomach!! Review by Chris

    I have used EFS in training and racing every distance triathlon from sprint to Ironman with fantastic success. As someone diagnosed with Ulcerative Colitis, I need to be extremely careful what I use on the race course. EFS is easy on the tummy and contains just the right mix of electrolytes for those of us who are digestively challenged! Get it, try it, LOVE IT! (Posted on 8/8/2014)

  8. Awesome!!!! Review by hikingshoes

    I wanted some type of powder so I could take it with me on my backpacking trips and my cycling. I've been using EFS going on two weeks ,on the second day of my workout I could feel the differences. This will be in my pack,at the gym, and on my bike each time I'm out. (Posted on 2/25/2014)

  9. IT ACTUALLY WORKS!!!!!!!!!!!! Review by ZERO

    I'm in the Marine Corps station on a Japanese Island, OKINAWA. The locals love their fitness as noted by regular 5K, 10K, 1/2 Marathon, Fulls year rd. I tried to run 14mi but repeatedly failed due to cramps. The first time I ran with EFS in my camel bak, I completed it an felt like I could do it again. I'm now using it to training for the Naha Marathon. I'm fully confident I'll be cramp free. (Posted on 9/22/2013)

  10. Hydration Review by Vero

    Racing is something that I am starting to learn how to do and I decided to get this product because my boyfriend made me taste it and it was great. The things that I like about it is the fact that it keeps the electrolytes in, the fact that there is not a bunch of crap added to it and no overload of sugar. Not only does this product help me push my boundaries, I know this may be too much information but I have caught a bug lately that has given me dirrhea and this drink is helping me big time with the hydration and electrolytes. (Posted on 2/11/2013)

  11. Awesome Review by Cycling Nut

    I was at my local bike shop getting a professional fit and the employee that was doing the fit suggested this to me. I bought a canister of the grape and it is awesome. I rode with my cousin the next day and had a personal best up a long HC climb and I felt the best I had all season. I will never drink anything else. EFS is just awesome!!!!!! (Posted on 8/23/2012)

  12. Great all the time! Review by Jeff

    Great product. No cramping ever when using, even training and racing in very hot conditions. Love the fact that it is very light flavor and can go down easily when it gets hot. Another great product!!! (Posted on 8/12/2012)

  13. No cramps finally Review by Brian

    I regularly had cramps with literally dozens of other drinks. I even went as far as to heavy and light dose the different products to get relief, but there wasn't a golden ticket for my cramping. EFS is one of those drinks that works exactly as prescribed and is THE only drink mix that allows me to ride without cramps. (Posted on 2/22/2012)

  14. Best drink mix. Period Review by Owen

    This stuff has always kept me from crampimg and never upsets my stomach. (Posted on 1/21/2012)

  15. works Review by joe

    Just starting using this efs and seen results as soon as i started it, my son runs xc, and is running better times and recovers very quick.I cant believe how well it works
    (Posted on 9/5/2011)

  16. great product Review by david

    i have used the efs drink for over 2 years now. i have done 2 ironman and several other tris. i train and race with the efs drink and think it is great. i have a very sensitive stomach so i am thrilled to have found something that works for me. also i have not used salt tablets so far, even with training in heat (washington dc area) since it seems to provide enough sodium for me too. (Posted on 8/9/2011)

  17. One word "AMAZING" Review by Amanda

    I used EFS drink mix before running a half marathon this year and it was my best friend. I ran the same race last year and didn't do as well as I'd hoped. I sweat A LOT and I had an electrolyte imbalance. I was told about EFS from a friend, so I decided to try it. I have never felt better on a long run EVER!! I felt great the whole race. I improved my time by 10 minutes. About 2 hours after my race I drank 12 more ounces of it and I felt great the whole day. I loved it!! It tastes great too. Very happy!!! (Posted on 7/25/2011)

  18. This Stuff Works!!!!!!!! Review by George

    This stuff really works, I've tried everything else and still cramped bad. I started taking EFS and I don't bonk anymore and the cramping has stoped. I'll won't use anything else and will only use EFS............ (Posted on 7/24/2011)

  19. It really works!!!! Review by mitchell

    It was great! I was getting head aches when I played in some rugby tournaments this summer. I was drinking alot of water and eating bannans but it didn't help me one bit. I went to the vitamine shop two days before a game in 90° weather, talked to the manager and he told me to try EFS. I played two games started to get a headache put a scoop in a bottle, downed it and I started to feel great the stuff really worked and I will continue to use it. (Posted on 7/21/2011)

  20. EFS has enhanced my training levels more than I thought was possible Review by H Romero

    I have been using EFS for a little over a month while on a very tough half ironman training program. I workout for about 10 to 15 hours per week and find myself in the top 3rd for most races. EFS has a great taste and is not too sweet or salty. It goes down very easy and I am able to drink 24oz per hour while running with a 165bpm heart rate. Before using EFS I was taking a gel every 20 min during runs and every 30 during biking. Now I take 1 gel per hour during runs and none on the bike if the ride is less than 3 hours. The biggest effect it has had on me is increased energy. I carry the gels like before but don't feel the need to take them. I have enough energy for the workout and extra at the end; but before I felt on empty all the time. The powder mixes very well by just shaking your run flask or bike bottle and completely dissolves in minutes. Something else I like is that it is CLEAR. Looks like water and will not stain your white jersey. I have had it hot, frozen then melted, and lukewarm and it is still refreshing each time I take a sip. So far I have had the grape and lime and loved them both. Good luck and I hope this helped. (Posted on 7/17/2011)

  21. consider it dialed Review by JM

    I tried it once, will never go back. funny thing is, i didn't really have too many complaints with my old nutrition, but once i tried EFS, it was over. Bloating on the run is a non-issue, gluten free is a huge plus. Works great with liquid shot as well, on the bike and run. amazing product, my nutrition is officially dialed! (Posted on 7/12/2011)

  22. great product Review by filolaos

    one of the best in the market (Posted on 7/7/2011)

  23. The Best Review by Matt Sheeks

    EFS pretty much destroys any other electrolyte drink available. It goes down easy, tastes great, and doesn't leave my stomach upset.

    In addition, EFS contains higher electrolyte concentrations then other products, and contains electrolytes that other products simply don't have (namely calcium and magnesium). So if you are looking for max benefit out of a glucose-electrolyte replacement drink, this would be the one.

    Aside from the holy grail of endurance supplementation, iron, the next three important nutrients to supplement with would be calcium, magnesium, and zinc. Cal, Mag, and Zinc have all been associates with improvements in endurance performance (see Peak Performance online for studies). Since EFS does contain calcium and magnesium, you are actually benefiting the short-term (electrolyte replacement) and long term (performance increase via mineral supplentation) by taking EFS. (Posted on 5/16/2011)

  24. Yummy! Review by Meredith

    I recently started using the lemon-lime EFS and it is YUMMY! I diluted it with a little more water to make it in a 16 ounce water bottle. It works great for bike rides. I love that it is clear and does not stain my water bottles. Now, if there were an easy way to mix it on the fly while riding my bike.... (I'm taking suggestions!) (Posted on 3/30/2011)

  25. Success with EFS Review by dean

    What is EFS: Electrolyte Fuel System.

    It comes in two formats powder/drink and liquid shot format. This write up will be about the drink/powdered format.

    I have only once previously tried with 1st Endurance and have finally purchase a full 25 serving bucket to use long term. For me, I think the 25 serving will last about 2 months or about 800 miles of riding. I'm gonna try to track how long it really last. I am three weeks in on the Fruit Punch flavor. I have heard the Grape flavor is great (that will be my next purchase)

    just lost my write up... have to do it again..sucks!

    I decided to forego my usual hydration/electrolyte mixture and go all the way for this weekend's race, Showdown at Sundown, with Fruit Punch flavor of 1st Endurance EFS.

    Benefits/ Features of EFS

    highest electrolyte content - over 1000mg compared to 162 to 430mg per 12 ounces.
    prevents cramping and dehydration
    mix at varying strengths (just about all powders are)

    Other info (per 12oz)

    96 calories
    200% DV of vitamin C
    16g of sodium
    24g of carbohydrates

    What are electrolytes (salts)? Calcium, potassium, sodium, and magnesium) and anions (of chloride, carbonates, aminoacetates, phosphates, and iodide). These are nutritionally called macrominerals. These are lost through perspiration or other forms of dehydration, particularly in heat stress situations.

    Why are electrolytes important? They allow cells to generate energy, maintain the stability of their walls, and to function in general. They generate electricity, contract muscles, move water and fluids within the body, and participate in myriad other activities.

    I started the bike leg with 32oz of Fruit Punch EFS. Premixed just short of 3 scoops with 32oz of water. Only one water/aid station on the bike and entered T2 with half consumed. I was sipping pretty much all day and was surprised with how much I had left. I even forced myself to take in extra liquid when I realized I how much I had left. I use the Oasis One-Twelve hydration system (single behind the saddle set up).

    What I noticed/like about EFS Sports drink from this weekends event and training

    was not dehydrated
    muscles still functined for the run
    very granular/not powdery - so no clumping and dissolves "quickly"
    clear, no artificial colors
    lots of electrolytes - I am not a heavy sweater, so it actually may be overkill for me, but I do not think anyone had been harmed by overdosing on electrolytes
    light flavor, no artificial flavoring. No candy like taste.

    What I dislike about EFS drink (just my opinion, everyone has personal taste)

    "Over" sodium taste. Yes, I can continue to dilute but that will water down the flavor and electrolyte content per serving.
    That "over" sodium taste gives it a "heavy" taste, similar to the older Gatorade Endurance formula.

    If I was a heavy sweater or the event was on a very hot day (ei Hawaii World Championship) I would not be complaining about this.. The race would a lot have to have lost of aid stations. Showdown at Sundown had only one water station on the bike.

    In conclusion I give 1st Endurance EFS Sports Drink rate an 8 out of 10.

    I will be going back to my "special" hydration mixture. But my pre-race hydration will be EFS Energizing Sports Drink! I will continue to use for my training rides and find that perfect ratio to eliminate the "over" sodium flavor. (Posted on 3/28/2011)

  26. Perfect Sport Drink Review by Laura Wheatley

    My favorite flavor is tart lemon-lime; the salty-sweet taste reminds me of a margarita! I no longer use salt tabs since the electrolyte content is so high, and I love that despite great flavor the drink is CLEAR so it doesn't stain my water bottles! (Posted on 3/27/2011)

  27. Excellent Review by Charlie W.

    I am so glad I chose to buy this product. Simply stated it has great taste. It is energizing and the cramps are gone. The drink is energizing and the thick feeling left in my mouth from using another product is gone. I am a devoted user. (Posted on 3/25/2011)

  28. Not too sweet Review by Savannah

    I would describe this product as "mellow". It is not overly sweet, so you do not get sick of the taste after a few hours. Plus, it seems to just get processed. This is one of those types of products that you don't want to notice. You just want it to work, and EFS Drink does just that. (Posted on 3/24/2011)

  29. No more bonk!!!!!! Review by Beth

    I live in a very hot climate, and I love long distance events. I have bonked more times than I would like to note. EFS is such a help. The electrolyte content keeps me on the bike and the run. No more bonk and no more sour stomach. It is light and clean. (Posted on 3/18/2011)

  30. The Only Drink for Me Review by Kelly

    During my first year of half-ironman training I struggled with nutrition. Every drink I tried upset my stomach. I started planning my long run routes around available bathrooms. Then I found EFS Drink. In the past year that I have used EFS, I have not had any tummy trouble during racing or training. The fact that I love the Grape and Fruit Punch flavors is a huge bonus!! There is no other drink for me. (Posted on 3/16/2011)

  31. Tasty! Review by Jeff Vanis

    I have tried the whole range of products from water to custom blended nutrition without ever being able to dial in exactly what my body needs... until now. I have only used single servings until this point, but plan on mixing up some double strength bottles in the near future.

    EFS is a great product, with a bit of flavor to give you more than water, plus packing a great amount of electrolytes. I have been using this for longer bike rides and runs so far and found it to be very gentle on the stomach, something that is often hard to find.

    I have only tried the Grape flavor so far, but look forward to trying the others in the near future. The taste is not too strong, but also enough that you know it is not just water. Grape has always been one of my favorites since childhood, and needless to say, EFS Drink does not disappoint!

    I have also been using one serving of EFS Drink in pair with a serving of PreRace before long workouts to ensure my body is stocked up and ready to go. This will become a race-day ritual! (Posted on 3/15/2011)

  32. Perfect! Review by Colleen

    I've struggled to find a product with a good combination of the electrolytes that I need during training and racing, and a flavor that I like. The Grape EFS drink is perfect. It's not too sweet, but definitely a great taste. I use one to two scoops in a normal bike bottle and the only problem I have is not chugging it! I'm a salty sweater and find that it replenished what I'm losing during my long and hard workouts - no cramps at all either! I've finally found the perfect combo - Can't wait to try other flavors! (Posted on 3/13/2011)

  33. Hands down best drink on the market! Review by Jill

    I tried EFS several years ago in an attempt to find a drink with higher electrolytes vs. calories. I had been struggling with finding a nutrition plan that would work for me over the longer distances. I sweat a lot and loose a lot of electrolytes in the process. EFS works great delivering energy and electrolytes in a formula that TASTES GREAT. This to me is the most important factor. I WANT to drink and that means I'm more apt to drink when I need to. The flavors are all great, none of them are too sweet, even at the end of a 5 hour ride in the GA heat. (Posted on 3/11/2011)

  34. Light drink taste with all the electrolytes (and more!) Review by Anthony

    I love clean crisp taste of the lemon lime, and very subtle grape and orange flavors. The sweet sticky products just bog me down after a few hours. I've had problems with cramping in the past and haven't had any trouble what-so-ever since turning exclusively to EFS. If I think I need the extra calories, I dump in some vanilla liquid shot. I can't do the fruit punch flavor though, reminds me of cotton candy. (Posted on 3/7/2011)

  35. My Perfect Endurance Drink! Review by Kati

    I have yet to find a flavor that I don't like, so I drink them all - I even mix flavors for new flavor combos! I really do drink only coffee, water, ultragen and EFS - (and EFS mixed w/ PreRace on special mornings) I bring a bottle along for a long swim, have a bottle after a medium workout that didn't require any nutrition or Ultragen, it comes along in a flask on my long runs, always, always on the bike - I can't say enough about how well EFS sits in my stomach. It's Gluten Free and the balance of sugars does what so many other sports drinks have failed to do for me - allow me to train and race stomach cramp free!! (Posted on 3/6/2011)

  36. Love EFS! Review by Mandy

    I made the switch to EFS last year and I have never looked back. I love that this isn't super sweet or sugary like other sports drinks I have tried. I never get stomach issues or cramps since I started using it. I used this on all of my long bike rides and runs last summer - this stuff rocks. EFS drink has the perfect mix of carbohydrates and electrolytes to get me through the longest or highest intensity sessions. Mild Grape is my favorite! (Posted on 3/1/2011)

  37. Great nutrition, no stomach issues Review by Christina

    In the past for ironman distance I have had GI issues, especially on the run. with the EFS drink I have eliminated my GI issues and it tastes much better than other nutritional drinks i have had to make myself drink. This is actually enjoyable. Fruit punch is my go-to flavor though I have had some friends say it is too sweet. It depends on how concentrated you make it as well. I fully recommend trying this product - especially if you have a sensitive stomach. (Posted on 2/28/2011)

  38. OUTSTANDING!! Review by Cooper Tri Machine

    Not only is it very effective, it taste awesome! Works like a charm and I have tested all of them out there. I'm converting from Hammer Nutrition products due to effectiveness and much better flavor! (Posted on 2/26/2011)

  39. Don't leave home without it Review by Hillary Biscay

    EFS has become my go-to fuel for all of my swim and bike workouts. I use a scoop in each bottle and find that it is the perfect mix of carbs and electrolytes to get me through even the longest or highest intensity sessions. I like all the flavors but Mild Grape is my fave! (Posted on 2/26/2011)

  40. Made The Switch Review by Triguy

    Recently made the switch from those other products that always left me bloated and cramping on the run. Since starting with EFS I have had some of the strongest training sessions I have ever experienced with zero cramping. Can't wait to use your product in upcoming half and full IM events this year. (Posted on 2/22/2011)

  41. No more cramps! Review by Josh

    Before last year, I used several different drinks to try to get me through events, but usually ended up battling cramps at some point. Then I switched to EFS Drink, and the cramps stopped. It blends the electrolytes and calories you need without the overpowering taste of other drinks. The grape flvor is light and refreshing. Good-bye cramps! Thanks First Endurance! (Posted on 2/22/2011)

  42. Best drink ever Review by Rick Reehl

    I have been using HEED for a while because I did not know better. I tried EFS and realized that HEED was just Kool Aid. EFS is simply the best drink out there. Check the labels and see for yourself. I will never go back to any Hammer products now that I have discovered your product line. (Posted on 2/22/2011)

  43. No more cramps Review by Josh Scobey

    Before last year, I used several different drinks to try to get me through events, but usually ended up battling cramps at some point. Then I switched to EFS Drink, and the cramps stopped. It blends the electrolytes and calories you need without the overpowering taste of other drinks. The grape flvor is light and refreshing. Good-bye cramps! Thanks First Endurance! (Posted on 2/21/2011)

  44. Best electrolyte drink... Review by alexander

    I used Gatorade when training for Ironman, because that is what was served during the race. I had no history or background knowledge on nutrition, as I signed up for Ironman as a novice. That was back in '08. Since then I have tried many different electrolyte drinks. I found that while I didn't experience the "explosive effects" that Gatorade had on many of my friends, I found it bloated my stomach and was hard to drink when I was thirsty. It was so syrupy that I couldn't drink it. I had to supplement my gatorade with electrolyte replacement pills in order to effectively replenish my electrolytes during exercise. Robert was giving away samples in IM CDA '10 and I took a sample of this and the EFS shot. I no longer had to use both electrolyte pills and electrolyte drinks. In addition, I much preferred the taste of EFS Fruit Punch over any gatorade or Hammer flavor. (Posted on 2/16/2011)

  45. Just right - Fruit Punch Review by Chris Garges

    I've tried all of the flavors of the newly redisigned EFS over the past year. While none of them are "bad", the Fruit Punch has been my "go to" flavor. It has just the right amount of sweetness to it. The Mild Grape is great if you want to double up dosage for a long event.

    The electrolyte count in EFS is second to none. There's no need for salt tablets, EFS has you covered. I've also experienced no GI issues (I've raced up to 70.3 distances).

    Good Stuff! (Posted on 2/16/2011)

  46. Great taste, great results! Review by Janet

    Starting in 2010, I switched to the EFS sports drink and have never looked back. I absolutely love the fruit punch flavor and the best thing about that is it helps me to drink it more, which I really need.

    I used a blend of water, EFS sports drink and the liquid shots to get through my first full distance triathlon last year and I had no issues whatsoever with my nutrition. I am so thankful to FE for providing such quality products! (Posted on 2/15/2011)

  47. Refreshing and powerful Review by JC Ramirez

    I was already a fan of EFS drink version 1.0. Revamped with more electrolytes and aminos, the stuff that was already great has been made awesome. Though all the flavors are good, for me, grape is IT. For racing Ironman, I can pack in the calories into one bottle without an overpowering sugary flavor. (Posted on 1/19/2011)

  48. friendly on the stomach Review by Richie

    Lemon Lime is my favorite. EFS is great for athletes who get digestive issues during workouts, runs in the heat, etc. It settles much better in the stomach than drinks like gatorade. The flavor is pretty strong, so I usually add more parts water than what is directed on the box. (Posted on 1/18/2011)

  49. Best quality, great taste! Review by Donna

    When I race and train, I like having the confidence that I'm fueling my body with the best products available. Not only does the EFS drink taste great, but it also contains the highest electrolyte content of any drink on the market. I've had no cramping issues since I started using the EFS drink, and I'm always sure to drink enough because it tastes great! (Posted on 1/17/2011)

  50. Awesome, light taste that won't give you stomach cramps! Review by Sarah Haskins

    When it comes to hydrating during a race or workout; nothing out on the market rehydrates you better than EFS. What I love about this sports drink, is that it is not too sugary like other drinks I have tried that had left me feeling bloated and off. The taste is light and refreshing and although I like all the flavors, the lemon lime is my favorite. The drink is also includes vitamin C, potassium and sodium which keeps you going through those longer cycling rides or brick workouts. I always remember to pack my EFS with me on the plane and racing/training trips. (Posted on 1/12/2011)

  51. Amazing! Review by mike

    Simply amazing! (Posted on 1/8/2011)

  52. Thirsty anyone?...not anymore Review by Mix

    I have been using this product everyday I ride with Bissell pro cycling team. It is one thing I love having on my bike. I always look forward to reaching down and taking the bottle out for a drink. No sick feeling, even after 10 of them (which I drunk in one race over 6hrs). Has everything you need to be your best. Awesome! (Posted on 12/2/2010)

  53. Make the switch...never look back. Review by Snak Snak

    This is the only sports drink on the market that has eliminated my muscle cramps during intense training/racing. I've tried all the other well known products with less than desireable results. EFS goes down easy, tastes great and never upsets my stomach. Cramping is now a thing of the past. 1 scoop 30 mins before a race plus 2 scoops an hour for me is the best ratio. You won't be dissapointed with this life-giving nectar from the Gods (aka First Endurance). (Posted on 11/15/2010)

  54. Perfect for any triathlete Review by Jimmy

    This product is amazing...No more getting tired during those 75 to 100 milers. I put 2 scoops in 2 bottles and grab a Liquid Shot and off I go. I've never had any kind of a cramp or discomfort in my stomach during or after my workout. Its a very smooth drink, alot like a sports drink, but nothing like an energy drink or mix. Try it.... and keep hammering it. (Posted on 11/11/2010)

  55. Everything you need in a drink Review by James

    Ever since I switched to EFS for my primary electrolyte source cramps are a thing of the past. Depending on the ride, 1-2 scoops per bottle is perfect for me. I used to have to supplement my electrolyte drink with pills and other sources to get the right amount of sodium and calories. Once I switched to EFS I found I didn’t need the supplements anymore because of the higher electrolyte content and calories. EFS has the perfect balanced to sustain me for any 1:30-2:30 hr. race. If I’m doing an endurance race over 2:30 hrs I just add some EFS Liquid Shot to get some extra calories. Best of all is the flavor; my favorite is Fruit Punch which tastes kind of like a fruit punch sweet tart. Thanks First Endurance for an awesome product. (Posted on 11/9/2010)

  56. Keeps cramps away! Review by Megan

    I used to get severe calf cramps during every swim I'd do, and it would end my workouts disastrously and painfully. I started drinking EFS Energy Drink for training after giving it a try per a friend's suggestion, and quickly noticed the cramps stayed at bay during my long swim sessions. I now rely on EFS as my go-to sports drink, and it is so easy on my stomach. I used to rely on Cytomax, but EFS is not as overpowering on the sweet-side as Cytomax, and I don't have any stomach discomfort with EFS whatsoever, like I would get after two bottles of Cytomax! Plus, the flavors are amazing. My favorite is the new Fruit Punch! (Posted on 11/8/2010)

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Q: What is EFS?
A: EFS 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 contain Vitamin C?
A: EFS 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. Click here for more info.

Q: What electrolyte upgrades can we find in the new EFS?
A: There are now 300mg of sodium per serving in the new EFS drink (previous formula had 270mg). This represents the highest sodium content in any electrolyte drink on the market. The EFS formula now offers over 1,160mg 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 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: The new EFS drinks now have Malic Acid, why is this important?
A: The new EFS drink contains 700mg of Malic Acid, which was not found in the previous formula. 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: Did the flavors change?
A: Yes, the new formulas went through extensive flavor testing in the most demanding races in the world. Our pro athletes tested the new formulas during the Tour de France, Ironman Hawaii and various other cycling, triathlon and running races. We used this extensive feedback to create all new low sweetness, mild flavors that are very palatable during a wide variety of environmental conditions. The new EFS formulas are all free of any artificial sweeteners, colors and flavors. All formulas use 100% natural flavors and contain NO color. This allows athletes to use EFS not having to worry about staining water bottles. The new flavors, especially the Grape and Orange do well up to 2X the recommended concentration.

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 Branched Chain Amino Acids and Glutamine. Clinical evidence supporting the use of Branched Chain Amino acids 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 ‘NEW’ 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 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
  • Replenish electrolyte loss

Q: How does it taste?
A: EFS is a light, great-tasting energy drink that’s sweetened and flavored with 100% natural ingredients. Because EFS is low in sweetness, there is no need to dilute the recommended serving allowing you to drink it full strength. Unlike energy drinks that contain complete proteins, EFS is not chalky and thick. The benefit is a potent, easy to digest energy drink which delivers all the nutrients like they were intended (full strength). EFS is available in four refreshing flavors: Lemon-Lime, Fruit Punch, Mild Grape, and Orange Splash.

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, 17
heat, 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?
A: The following symptoms will all benefit from use of EFS

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 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. The high sodium content in EFS may even help reduce the drinks propensity to freeze. (this has not been tested).

Q: Should I use EFS 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 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 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) cells experience damage from cellular oxidation 3) electrolytes are depleted and 4) amino acids are depleted.

1) EFS 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.

2) EFS provides the most potent electrolyte profile available. The combination of all five electrolytes deliver a potent 1040mg per serving, helping to prevent cramping. The 300mgs 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.

3) 2000mg of Amino Acids offers the same BCAA and Glutamine levels as 9g Whey Protein. These amino acids have clinically shown to improve performance, reduced post-exercise muscle damage, improve muscle glycogen resynthesis, reduced central fatigue and improved rate of perceived exertion.

Q: What’s the carbohydrate source in EFS?
A: EFS 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.

Q: I am prone to cramping during longer training and racing. Will EFS help me with cramping problems?
A: Nutritionally cramping stem from electrolyte imbalance, electrolyte depletion and/or dehydration,. EFS provides the most potent electrolyte profile available. The combination of all five electrolytes deliver a potent 1040mg per serving, helping to prevent cramping. The 300mgs 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 many servings are in a container of EFS?

A: There are 25 servings per container of EFS

C of A

Click here for Certificate of Analysis archive.


Clinical research shows endurance athletes require much higher levels of electrolytes than most sports drinks provide to prevent cramping and dehydration (4). The new EFS drinks now contains over 1,160mg of all 5 electrolytes per serving, more than any electrolyte drink on the market.

The Amino Acids in the EFS 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.

The new EFS formulas utilize two unique sources of calcium and magnesium. DiCalcium malate and Dimagnesium malate have superior bioavailability compared to other mineral sources. In a bioavailability study, absorption rates were between 20% and 100% higher using DiCalcium and DiMagnesium malates (1).

EFS drinkS contains 700mg of Malic Acid to stimulate 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 to make ATP more efficiently, even under low oxygen, or hypoxic conditions.

(1) Chaturvedi, P, et al,. Comparison of calcium absorption from various calcium containing products in healthy human adults: a bioavailability study. KGK Synergize FASEB 2006.
(2) Bassit RA, et. al, Branched-chain amino acid supplementation and the immune response of long-distance athletes. Nutrition. 2002 May;18(5):376-9
(3) Jentjens RL. Underwood K. Achten J, Currell K, Mann CH, Jeukendrup AE. Exogenous carbohydrate oxidation rates are elevated after combined carbohydrate sources during exercise in heat. J Appl Physiol. 2006 Mar; 100 (3):807-16.
(4) Brouns, F., et al. 1992 Rationale for upper limits of electrolyte replacement during exercise. Int J Sport Nutr 2:229-38.

Click here to download the EFS research packet in Adobe Acrobat format.


Supplement Facts
Serving Size: 1 scoop (32g)
Servings per Container: 25
Amount Per Serving%DV
Calories-96 Calories from fat-0
Total Carbohydrate (Complex carbohydrates, Dextrose, Sucrose) 24g
Sugars 16g **
EFS Total Electrolyte Blend (Ca, Mg, Cl, Na, K) 1160mg *
Calcium (as DiCalcium Malate) 100mg 10%
Magnesium (DiMagnesium Malate) 150mg 38%
Chloride (as sodium chloride) 450mg 10%
Sodium (as sodium chloride) 300mg 15%
Potassium (as di-potassium phosphate) 160mg 6%
Malic Acid (from DiCalcium and DiMagnesium Malate) 700mg *
AjiPure Amino Acid Blend (L-Glutamine, Leucine, Iso-Leucine, Valine) 2,000mg *
*Daily Value Not Established
**Percent Daily Values are based on a 2,000 calorie diet.

Ingredients: Complex carbohydrates, sucrose, dextrose, AjiPure Amino Acid Blend (L-Glutamine, Leucine, Iso-Leucine, Valine), Electrolyte blend (chloride, sodium, potassium, magnesium, calcium), citric acid, natural flavors, ascorbic acid.