Updated for 2021

After months of research-driven tinkering, testing, and trial, we’ve updated the formulas for EFS and EFS-PRO hydration mixes. Given the technical–and, frankly, revolutionary–nature of both formulas, we compiled a list of changes to quickly highlight and explain the differences and confirm what’s stayed the same.

With the new EFS and EFS-PRO, you’ll never have to take additional electrolyte pills/tablets again.

Key Features

What’s new?

The big changes to both formulas involve targeting mental toughness. EFS and EFS-PRO have long led the industry in supporting physical performance, but–until now–endurance hydration mixes have neglected the mental side of suffering. Mental toughness is arguably as important as physical support because, without it, an athlete can’t push beyond their perceived limits in order to reach their true potential.

EFS

Patented Suntheanine® L-theanine: An amino acid that signals a calming response in the brain. Helps maintain focus under duress, supporting mental toughness when your legs are screaming at you to stop.

  • Flavor: Tested, tested, rejected, tested again. Though flavor’s not strictly a technical or performance-enhancing feature, it’s easily among our favorite changes.
  • More calories – Now 10% more calories per serving (110 vs 100)
  • Improved mixability. Goes into solution easily. More like powdered sugar now vs granulated sugar.

 

EFS-PRO

Patented Suntheanine ® L-theanine: An amino acid that functions as a calming neurotransmitter. Helps maintain focus under duress, supporting mental toughness when your legs are screaming at you to stop.

  • Flavor: Tested, tested, rejected, tested again. Though flavor’s not strictly a technical or performance-enhancing feature, it’s easily among our favorite changes. Very mild flavors.
  • PharmaGABA: The neurotransmitter that promotes calm focus. Keeps your brain balanced, so you can maintain control and push through pain-induced panic.
  • Improved mixability. Goes into solution easily. More like powdered sugar now vs granulated sugar.

 

What stayed the same?

EFS

  • Electrolytes: Far outpaces the competition, including between double and triple the electrolyte content as other hydration mixes. Only EFS-PRO is better at preventing cramps.
  • Fueling: Delivers more carbohydrates than the competition in an osmotically balanced 7% solution. More fuel that processes faster without GI distress.

EFS-PRO

  • Electrolytes: Provides even more electrolytes than EFS–truly professional-grade cramp prevention. No other hydration mix is as effective.
  • Fueling: More advanced carbohydrates optimally balance fuel consumption. The only source of carbs you need during a workout.
  • Scalable mixability: EFS-PRO can be mixed at higher concentrations to deliver more electrolytes and fuel without GI distress. It’s even easier to absorb and digest than EFS. 

Details of the new features

Patented Suntheanine ®
Activates your brain to maintain alertness and focus under stress, keeping your responses organized and productive. Helps you overcome a natural inclination to govern or dial back your efforts during the high-stress, high-output moments that define things like race finales, hill repeats, and intervals—the exact moments when you most need to be operating at full capacity but when physical and mental fatigue are screaming at you to stop.

Suntheanine is a patented source of L-theanine that represents the purest, most reliable product available. Since it’s pharmaceutical grade, Suntheanine is what was used for the majority of the clinical research that informed our formula redesign, making it the obvious choice to meet our uncompromising standards.

We tailored our EFS and EFS-PRO formulas with a measured amount of Suntheanine to maintain a steady, constant calming effect across the length of a race or workout, rather than a daily dose that may produce a positive effect for a short time but fades as the amino acid is metabolized.

Learn more about the Suntheanine L-theanine here.

Flavor
Some might say we spent way too much time and energy testing, formulating, rejecting, and revising flavors. Anyone who’s hit a wall where sweetness fatigue or the prospect of another mouthful of salty, chemical-tasting sludge knocked them out of competition or upended a day’s training plan knows that flavor and mixability can’t be over-improved. We ran through several batches of flavors, leaving most of them on the drawing room floor before finally settling on the winning menu.

We’re damn proud of what we came up with–mostly because we actually like how it tastes. Truly novel for a performance hydration mix.

PharmaGABA
PharmaGABA is the actual neurotransmitter that promotes calm focus. It keeps your brain balanced, so you can shrug off stress and the pain-induced panic that make you dial back your efforts during high-stress, high-output moments in races or training sessions. Including Suntheanine and PharmaGABA in EFS-PRO provides a double-dose of support for mental toughness. Learn more about PharmaGABA here.

Scalable mixability
EFS-PRO is 100% soluble in water and uses branched-chain cluster dextrin (CCD) as the primary fuel source. Its perfect solubility means it won’t congeal or thicken into sludge, and CCD is isotonically aligned with your body’s internal chemistry, which means it doesn’t overload the osmotic balance in your GI tract, even when you take advantage of EFS-PRO’s solubility to mix it at double or even triple concentrations to increase electrolyte and carbohydrate delivery.

More fuel, more electrolytes, no sludge, no uptake issues–EFS-PRO effectively deletes the ceiling for delivery and uptake of the crucial tools your body needs to perform in the most demanding conditions.

When to go PRO

One of the most common questions we get pertains to when to use EFS-PRO instead of EFS. In extremely hot conditions, we recommend using EFS-PRO exclusively. We also recommend it for grueling, high-exertion sufferfests.

EFS-PRO’s scalable mixability means the electrolyte and fuel content can be ramped up as needed to meet whatever conditions or exertions a given day brings. It’s for the most extreme applications: blistering summer days, racing and sweating in extreme heat, and all-day outings with high output.

April 20, 2021 — First Endurance

Comments

Michael said:

Hi Julia,

We have an all-new, completely redesigned, high carb EFS-PRO coming out on Jan 8. There’s a 100% guarantee.

Julie A said:

I have used EFS for nearly 15 years. I love it, it really works better than other sport drinks. I have even used the pro on occasion. However, the new version is causing me so many issues. I’m not sure what about it is the source, but I would like to figure it out. It causes mental confusion, nausea, diarrhea, and muscle weakness to name a few. I’m not going to use the pro version anymore, but will go back to the regular version. Do you have any information on what the source of these issues is? Thanks.

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