Formulation
How your Level is built
LEVELEN is one electrolyte formula made at increasing sodium levels. A lab analysis of the sweat you lose in training decides which Level is yours. This page covers the science, the method and every ingredient, with sources.
Why one formula fails
Athletes do not sweat the same
A one-size-fits-all electrolyte drink assumes athletes lose roughly the same amount. The research behind LEVELEN shows how far apart they are, even with a similar diet, body type and size. [1]
Sodium lost per hour differed by more than 100-fold between athletes in LEVELEN's research with the Philadelphia Eagles and Philadelphia Flyers. [1]
Sweat volume per hour differed by more than 37-fold from one athlete to another. [1]
The lowest and highest sweat rates seen across thousands of athletes tested. The average was 1.68 liters per hour. [1]
The range of sweat sodium concentration across 44 professional football players in a single preseason. [3]
Size and sex explain only a little of the difference. Larger athletes tend to sweat more and men tend to sweat more than women, yet two athletes of similar size and sex can have very different sweat volumes. [1] In identical conditions, football players lost over 9 liters of sweat a day compared with about 3 liters for runners. [1]
Electrolyte loss varies even more than fluid loss. As electrolytes run low, performance can slip gradually and without warning, and when depletion becomes more extreme, muscle cramps can set in. The point where that happens is different for every athlete. [1]
Why blood tests miss it
Your blood looks normal
The body pulls blood sodium back to its normal range of 135 to 145 mmol/L, usually within about an hour, even after cramping. A blood test taken later will most likely read normal and cannot show what you lose while you train. [1]
Why guidelines miss it
Guidelines cannot see your sweat
General hydration guidelines cannot tell one athlete what they need, and no metric accurately predicts an athlete's hydration needs. That is why LEVELEN tests the sweat itself. [1]
What the extremes look like
30 grams in a day
During preseason two-a-days, average sodium loss in NFL linemen was 12.5 grams a day, and one player lost more than 30 grams in one day. Replacing 30 grams from a standard sports drink would take about 65 liters of it. [3]
The patented method
The Sweat Test, step by step
LEVELEN's method is covered by U.S. Patent 9,421,226 B2, granted in 2016 to Dr. Arthur Bartolozzi and Dr. Sandra Fowkes Godek. In plain terms, it measures how much an athlete sweats over time and how much sodium that sweat carries during hard exercise, assigns the athlete to a sodium group, and matches the drink to that group. [2] Here is how you collect your sample at home. [1]
Plan a normal session
Test during the activity, intensity and conditions you are training for, for example a hot-day run if you are training for a hot marathon. Aim for a continuous workout close to one hour.
Clean and patch
Clean the outside of your forearm below the elbow (the side facing up when your palm faces down) with the alcohol swab and let it dry. Apply the sweat patch just before you start.
Weigh in
Empty your bladder and weigh yourself with minimal or no clothing. Note the weight and, if you can, the temperature and humidity. From now until you weigh out, record every ounce or milliliter you drink.
Train and collect
Remove the patch when the gauze is fully saturated, usually 30 to 45 minutes in (wear it at least 30 minutes and up to an hour). Use the tweezers so you never touch the sample, place the gauze in the vial, snap the lid shut, seal the bag and keep training.
Weigh out
Wipe off your sweat and weigh yourself again with minimal or no clothing. Note your weight, the workout length and intensity, and the fluid you drank on the information card.
Mail it to the lab
Send the card and sample back in the return mailer, and photograph the tracking label in case the package is lost.
Get your Sweat Profile
The lab measures sodium, potassium and chloride in your sweat and calculates your sweat rate. Your Individual Sweat Profile and Dashboard are emailed to you, normally within 1 to 2 weeks after your sample arrives.
If you held or gained weight during the test, you drank too much and the test needs to be redone with less fluid. [1]
Why the method matters
Real sweat, measured directly
Collected during your own workout
Collected while you work
Stimulated sweat tests are medically approved for detecting cystic fibrosis. Sweat produced by a chemical stimulus differs from sweat produced by heat during exercise, and studies show the stimulated method gives higher electrolyte concentrations than true thermal sweating. LEVELEN collects eccrine sweat produced during your own workout. [1]
Each electrolyte measured
Nothing estimated
Many tests measure chloride and estimate sodium from it. LEVELEN analyzes each electrolyte independently. Sodium and chloride usually track together, but the lab has seen many cases where they differ widely, which would make an estimate wrong. [1]
Your Level
How a Level is assigned
Sodium is the electrolyte you lose fastest, so it is the main one the lab assesses. Chloride is lost at a highly predictable rate relative to sodium. [1] Your Level is set by the electrolyte concentrations in your sweat, and it is spelled out in your Individual Sweat Profile. [7] Under the patented method, each athlete is assigned to the sodium level they most closely match. [2]
The LEVELEN scale runs from Level 1 to Level 5. Levels 1 and 2 describe lighter salt losses that a standard sports drink already covers, so LEVELEN makes its mix only in Levels 3, 4 and 5, where a generic drink falls short. Nutrition and ingredients are identical at every Level; only the electrolyte content changes. [7]
Your Sweat Profile includes: sweat rate, sodium concentration and sodium loss per hour, potassium concentration, chloride concentration and chloride loss per hour.
Your Dashboard includes: sweat rate, recommended fluid intake, your rate of fluid and electrolyte loss, your recommended LEVELEN Level, and a hydration and electrolyte plan built from your results.
Levels 1 and 2
Level 3
Level 4
Level 5
Ingredients
What is in the mix, and why
From the current LEVELEN labels. [8] Mix one level scoop in every 14 oz of water: 56 g for the flavored mixes, 42 g for Neutral. The flavored versions add natural flavors, citric acid, green tea extract and fruit and vegetable juice powder for color; Neutral leaves them out. [8]
| Ingredient | What it does | In which mix |
|---|---|---|
| Sodium chloride | Replaces the sodium and chloride lost in sweat. Sodium is the most rapidly depleted electrolyte; the amount is what changes from Level to Level. | All |
| Dextrose (glucose) | Used instead of sucrose, fructose or high fructose corn syrup to help absorb and retain electrolytes and to limit the stomach upset linked to digesting complex sugars. | All |
| Maltodextrin | A second carbohydrate, listed with dextrose on the label. | All |
| Magnesium (magnesium dihydrate lactate) | Supports cell membrane transfer so the body retains electrolytes and fluid. 32 mg per serving. | All |
| Vitamin and mineral blend | Calcium lactate gluconate, vitamin C (ascorbic acid), vitamin E, biotin, niacinamide, pantothenic acid, vitamin B12, vitamin B6 (pyridoxine) and sodium selenite. | All |
| Malic acid, apple cider vinegar powder, tricalcium phosphate | Listed on the label as part of the base formula. | All |
| Natural flavors, citric acid, green tea extract, fruit and vegetable juice powder | Flavor and color for the flavored mixes. | Flavored only |
| Potassium | 0 mg per serving. Left out deliberately; see below. | None |
Ingredient roles come from LEVELEN's published formulation notes. [1] [7] All ingredients are suitable for tested athletes: none appear on anti-doping lists. Gluten-free and vegan-friendly. Precaution: people with hypertension or renal disease, or who take diuretics, should consult a physician before using LEVELEN. [8]
The potassium question
Why LEVELEN has no potassium
Many sports drinks add potassium. LEVELEN leaves it out on purpose. When you train, your muscle fibers break down and release potassium, and the body regulates potassium efficiently even at modest activity levels, so it does not need replacing during exercise. [1]
Contrary to popular belief, potassium deficiency does not cause muscle cramping. Abnormally high blood potassium (hyperkalemia) is dangerous and can be fatal, so LEVELEN avoids potassium supplementation. Leaving it out does not reduce the mix's ability to address cramping. [1]
Abstract
Sodium chloride, no potassium
Ten NFL players received about 4,500 mg of sodium and 6,926 mg of chloride a day above their normal diet, in drinks with added sodium chloride and no potassium, over the first 11 days of preseason. They kept normal pre-practice body mass, with no hyperkalemia or hyperchloremia. The authors concluded that sodium supplementation without added potassium helped the players maintain fluid and electrolyte balance. [4]
Peer-reviewed paper, 2009
Potassium rose without supplements
In a separate NFL training camp study, players' resting blood potassium rose by days 5 and 9 of two-a-days with no potassium added beyond their normal diet and the team's sports drinks, which the authors attributed to muscle breakdown from heavy training in the heat. [3]
Sodium chloride and the research
The studies behind the formula
Dr. Fowkes Godek's research library on the LEVELEN site holds roughly 30 abstracts, 9 publications and several presentations, grouped under electrolyte management, muscle cramping, sweat rates and thermoregulation. [1] These are the studies LEVELEN has published in full or as abstracts.
Peer-reviewed paper, 2009
Blood electrolytes in NFL preseason
Six NFL players were tracked through preseason camp. Blood sodium fell from 140.4 mmol/L at baseline to 136.9 by day 3 and was held at low-normal levels at the cost of reduced plasma volume. The authors concluded that eating and drinking more sodium is important for professional football players to maintain plasma volume in the first week of preseason. [3]
Abstract
Sodium chloride without potassium
Ten NFL players given about 4.5 g of sodium a day without added potassium maintained fluid and electrolyte balance through the first 11 days of preseason, without hyperkalemia or hyperchloremia. [4]
Abstract
Blood measures during cramping
Seven NFL players with exercise-associated muscle cramps were compared with seven matched players who did not cramp. Blood chloride was clinically low (under 100 mmol/L) in six of the seven during cramping and rose after IV treatment. The authors suggest low blood chloride may play a part in cramping; in this group, cramping was not linked to sweat sodium concentration or total sodium loss. [5]
How to use it
Turn your results into a plan
Your plan is built from three things: your Individual Sweat Profile, how long you train or compete, and your sport. [1] Here is the math the Dashboard uses.
Know your sweat rate
Sweat rate equals pre-weight minus post-weight plus fluid consumed, divided by workout time (kilograms, liters and hours). Example: (73 kg minus 72 kg plus 0.5 L) divided by 1 hour equals 1.5 liters per hour. [1]
Set your fluid target
Your Recommended Fluid Intake on the Dashboard is 60 to 70% of your sweat rate. Use that figure, not your sweat rate, for planning. [1]
Find your total
Multiply your recommended intake by the length of the session. Example: a 5-hour triathlon session at 1.2 L per hour is 6.0 L of LEVELEN at your Level. [1]
Split it before, during and after
Drink about 35 to 40% of the total in the 24 hours before, 35 to 40% during, and 20 to 30% after. In the example: 2 to 2.5 L before, 2 to 2.5 L during, and 1 to 2 L after. [1]
Sweat rate calculator
Estimate your sweat rate
The same formula LEVELEN's Fluid Loss Calculator uses. [9] Sweat rate changes with heat, intensity and clothing, so run it in conditions like your event.
Enter all four values. Use kilograms or pounds for weight, and record everything you drank between weigh-ins.
Sodium per hour, by Level and fluid intake
Arithmetic from the published sodium per liter. Your Dashboard's recommended intake governs; this table only shows what each Level delivers at a given intake.
| Fluid per hour | Level 3 (900 mg/L) | Level 4 (1,200 mg/L) | Level 5 (1,500 mg/L) |
|---|---|---|---|
| 0.50 L | 450 mg | 600 mg | 750 mg |
| 0.75 L | 675 mg | 900 mg | 1,125 mg |
| 1.00 L | 900 mg | 1,200 mg | 1,500 mg |
| 1.25 L | 1,125 mg | 1,500 mg | 1,875 mg |
| 1.50 L | 1,350 mg | 1,800 mg | 2,250 mg |
Timing by sport
From LEVELEN's sport guidance. Severity labels (Low/Mild, Moderate/Significant, Severe) come from the fluid loss result on your Sweat Profile. Starting more than 36 hours ahead adds no benefit. [1]
| Sport | Start before | During | After |
|---|---|---|---|
| Football | 24 hours before a game or hard practice; 36 hours if fluid loss is Severe | Drink available fluids at your recommended rate. In two-a-days, keep taking LEVELEN through the whole period. | Keep rehydrating with available fluids at your recommended rate |
| Hockey, basketball, soccer, lacrosse | 24 hours; 36 hours if fluid loss is Severe | LEVELEN on the bench if you can; otherwise available fluids at your rate | Continue through tournaments and playoffs |
| Cycling | 24 hours; 36 hours if fluid loss is Extreme | Carry LEVELEN on the bike; pack single servings for long rides | 6 hours (Low/Mild), 12 (Moderate/Significant), 24 (Severe) |
| Distance running | Up to 36 hours for your longest events; 24 hours for shorter ones | Course water is often all there is, so the before and after matter most | 6, 12 or 24 hours by fluid loss result |
| Triathlon | Up to 36 hours for long events; 24 hours for shorter ones | Stock LEVELEN in transition and on the bike | 6, 12 or 24 hours by fluid loss result |
| CrossFit and lifting | Up to 24 hours before | Through the workout | Add Neutral to your post-workout drink or protein shake |
Flavors
Three flavors, same science
Every flavor comes in Levels 3, 4 and 5, with the same sodium per liter at each Level. [7]
Crisp citrus
Lemon-Lime
Tastes like frozen lemonade with a touch of lime. It started as a custom request from one of LEVELEN's professional clients. 56 g scoop per 14 oz. [7] [8]
Light strawberry
Strawberry-Citrus
A lightly sweet strawberry with a mild hint of citrus, flavorful enough to enjoy and mild enough for the hottest days and hardest workouts. 56 g scoop per 14 oz. [7] [8]
Mild and clean
Neutral
Made at the request of endurance athletes. Mildly sweet in water, and it mixes into protein shakes or sports drinks without overpowering them. 42 g scoop per 14 oz. [7] [8]
FAQ
Formulation questions
Why is there no potassium?
Your body releases potassium as muscle fibers break down during exercise and keeps blood potassium balanced without supplements. Potassium deficiency does not cause cramping, and too much potassium (hyperkalemia) is dangerous. [1] More on potassium.
Should I worry about taking in too much salt?
Competitive athletes can lose large amounts of salt, but the amount is highly individual. The goal is to replace what you lose, not to add sodium you do not need, which is why your Level is based on your own Sweat Test. [1]
Can I still eat salty food?
In most cases, keep your normal diet. LEVELEN is for immediately before and during training and competition. A few athletes' results call for more electrolyte replacement, and for them LEVELEN recommends more salt in the diet alongside the mix. [1]
My blood test was normal. Why test my sweat?
The body restores blood sodium to its normal range, usually within an hour, even after cramping, so most athletes test normal whether or not they cramp. A blood test cannot show your real-time losses. [1]
Does my Level change?
Year to year, LEVELEN's studies show results stay the same unless your diet, weight, medications or activity change a lot, so retest once a year. Season to season, acclimation shifts your sweat: in cool weather you sweat less but at a higher concentration, and in warm weather you sweat more at a lower concentration. Multi-season and multi-sport athletes may want several tests a year. [1]
Is LEVELEN safe for tested athletes?
None of the ingredients appear on anti-doping lists. [8]
Who should check with a doctor first?
People with hypertension or renal disease, or who take diuretics, should consult a physician before using LEVELEN. [8]
What if my Sweat Profile shows Level 1 or 2?
Your salt losses are on the lighter end, and a standard sports drink covers them, which is why LEVELEN only makes Levels 3, 4 and 5. Your Dashboard still gives you a fluid plan based on your sweat rate. Questions: support@levelen.com.
How long do results take?
Results are emailed to you, normally within 1 to 2 weeks after your sample arrives. [1]
Sources
Citations
LEVELEN. Hydration Sports Science: FAQs, sweat testing and research library. levelen.com. Archived copy.
Bartolozzi AR, Fowkes Godek S; HEAT Sport Sciences, Inc. Exercise physiology electrolyte management. U.S. Patent 9,421,226 B2. Granted August 23, 2016. Google Patents.
Fowkes Godek S, Bartolozzi AR. Changes in blood electrolytes and plasma volume in National Football League players during preseason training camp. Athletic Training & Sports Health Care. 2009;1(6):259-266. doi:10.3928/19425864-20091019-03. PDF.
Abstract: Blood, urine and body mass measures of fluid and electrolyte balance in NFL players supplemented with sodium chloride but no potassium during pre-season. Undated abstract, Fowkes Godek research program, published on levelen.com. PDF.
Abstract: A comparison of blood measures while NFL players are experiencing EAMC and after IV treatment when EAMC are alleviated. Undated abstract, Fowkes Godek research program, published on levelen.com. PDF.
Abstract: Ice slushie ingestion decreases core body temperature in male football players prior to a standard pre-season practice. Undated abstract, Fowkes Godek research program, published on levelen.com. PDF.
LEVELEN. LEVELEN Electrolyte Mix: formulation, flavors, ingredients and nutrition (Level 3, 900 mg; Level 4, 1,200 mg; Level 5, 1,500 mg sodium per liter). levelen.com product information page.
LEVELEN product labels, current packaging: Neutral and flavored mixes, Levels 3 to 5 (ingredients, nutrition facts, mixing instructions, precautions). Shown on the product pages.
LEVELEN. Fluid Loss Calculator and worksheet. levelen.com. Archived copy.
Know your Level
Find your Level with the Sweat Test
The Sweat Test gives you your sweat rate, your sodium loss and your Level, so you can fuel with the mix made for that Level.