Product Description
Cramping is a signal — your body telling you the minerals keeping your muscles firing have been sweated out faster than you're replacing them. Most drink mixes hand you two or three electrolytes and call it done. That's not enough.
EFS delivers a clinically effective dose of all five electrolytes, 30g of carbohydrates, and 1,175mg of total electrolytes in an isotonic formula your body can actually absorb. Zero artificial ingredients. This is what serious endurance fueling looks like.
All Five Electrolytes, at Doses That Actually Work Sodium, potassium, chloride, calcium, and magnesium — all five at clinically supported levels, not token amounts. At 1,175mg total electrolytes per serving, EFS covers your bases the way two-electrolyte mixes never can.
Isotonic Formula for Fast, Comfortable Absorption EFS mixes to a 7% carbohydrate solution — matching your body's own fluid concentration — so your gut absorbs it immediately. Faster delivery, less distress, no heavy mid-effort bloat.
30g of Multiple Transportable Carbs, No Artificial Anything Glucose and fructose absorb through separate gut pathways simultaneously, letting your body process more fuel per hour without GI overload. No artificial flavors, sweeteners, or colorants — and no Vitamin C, which research shows can impair endurance performance when taken mid-exercise.
Your gut has two separate carbohydrate transport channels — one for glucose, one for fructose. Running both at a 2:1 ratio lets EFS deliver more total carbs per hour without overloading either pathway. The isotonic concentration means the mix absorbs quickly without pulling water from your bloodstream or causing that waterlogged feeling. Citric and malic acids support oxygen uptake and energy production at the cellular level, while L-glutamine — equivalent to roughly 9g of whey protein — protects gut integrity and supports glycogen recovery without the digestive burden of whole protein.
How to Use First Endurance EFS Drink Mix
Pre-Workout: Mix one scoop in 16–20oz of water and drink 30 minutes before training or racing to top off glycogen and electrolyte levels before you start sweating.
During Exercise: Drink one serving every 30–45 minutes during efforts lasting over an hour. Adjust concentration based on sweat rate, conditions, and body size — more scoops in hot weather, longer efforts, or if you're a heavy sweater.
Stack It: Add First Endurance Liquid Shots to your bottles during high-intensity efforts or long races to increase carbohydrate intake without adding another container to carry.
EFS is used by professional cyclists, triathletes, and ultra-endurance athletes who train in some of the most demanding conditions in sport. Two-time World Hillclimb Champion Phil Gaimon and Team USA Biathlete Vincent Bonacci count on EFS to stay fueled without GI issues through their hardest efforts. At 4.6 stars across 140 reviews at The Feed, it's one of the highest-rated hydration products in the catalog.
Stop guessing at your electrolyte and carb needs on race day. EFS puts everything you need in one bottle — and nothing you don't.
- Gluten free
- Vegan
- 0g
- 0g
- 25g
- 300mg
- 30g
- 0g
Nutrition Facts
Lemon Lime / Single Serving (Best By 5/2026)
Serving Size: 1 Packet
Serving Per Container: 1
| Amount Per Serving | ||
|---|---|---|
| Calories | 120 | |
| % Daily Value* | ||
| Total Fat 0g | 0% | |
| Saturated Fat 0g | 0% | |
| Trans Fat 0g | ** | |
| Cholesterol 0mg | 0% | |
| Sodium 300mg | 13% | |
| Total Carbohydrate 30g | 10% | |
| Dietary Fiber 0g | 0% | |
| Sugars 25g | ** | |
| Protein 0g | 0% | |
| Caffeine 0mg | ** | |
| Potassium 160mg | 5% | |
| Magnesium 150mg | 38% | |
| Calcium 100mg | ** | |
| Chloride 465mg | ** | |
* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
** Daily Value (DV) not established
Always Happy Promise: Don't like a product? Tell us within 30 days of receipt and we'll make it right and make you happy. Here at The Feed, we want you to love your experience and the sports nutrition products you purchase. If, for any reason, you are not satisfied with your nutrition specific purchase, tell us.
We do not accept returns on food items that have been opened, but we will issue a store credit if you are unsatisfied. In the event of a return, you must first contact us before sending back a return shipment.
Consumable products over $40 receive a 50% store credit. This includes specialty nutrition products such as ketones or supplements/vitamins.
First Endurance EFS Drink Mix FAQ's
Everything you need to know before getting started.
Take one serving 30 minutes before training or racing to prime your glycogen and electrolyte levels. During exercise, drink one serving every 30–45 minutes for efforts lasting over an hour. It works both as a pre-load and an during-effort fuel source.
EFS is the everyday training and racing workhorse — 30g carbs and 1,175mg electrolytes per serving. EFS-PRO doubles the carbohydrate content and increases electrolytes further, making it the choice for the most extreme efforts and conditions. If you're doing sessions over four hours or racing in serious heat, EFS-PRO is the step up.
Yes to both. EFS contains no gluten, no animal-derived ingredients, and no artificial flavors, colors, or sweeteners.
For efforts up to about two hours, EFS alone can cover most athletes' carb and electrolyte needs. For longer sessions or high-intensity racing where you need 90g+ of carbs per hour, stack EFS with First Endurance Liquid Shots to hit your target without adding bulk.
The glucose: fructose ratio in the EFS formula is 2:1 Glc:Fru.