Are Electrolyte Supplements Necessary?
It depends! The goal of electrolyte supplementation is to replace lost sweat which supports rehydration and helps maintain thermal balance. More likely circumstances where sweat rate increases include 1) engaging in prolonged intense exercise (>1h), 2) working outdoors 3) engaging in activity at higher temperature, humidity, or elevation.
How Much Fluid do I Need? Calculating Sweat Rate
Sweat rate can vary greatly from person to person for the same activity; a useful way to personally assess how much sweat must be replaced by fluid is by measuring your sweat rate:
1. Before exercise, weigh yourself in a minimal amount of clothing you can train in.
2. Take defined amount of fluid with you for the training session and drink as needed during the session….e.g. 20 oz.
3. After the workout, towel off excess sweat and weigh yourself again in minimal clothing.
Example: let’s say I run for one hour. I weigh 150.2 lbs. initially and drank 20 oz. (1.25 lb.) of water during the workout. After the workout I weighed 148.3 lbs:
Fluid loss = initial weight – final weight – weight of fluid consumed.
150.2 – 147.3 – 1.25 = 1.65 lbs. = 16 oz./hr.
For high intensity exercise extending 90 minutes or more, it becomes increasingly important to ensure fluid regulation and fuel supply. Sip a drink containing electrolyte (and carbohydrates) throughout exercise.
Comparison of Electrolytes
The below table compares popular electrolyte brands versus the reference ranges in 1 L (33.8 oz.) of human sweat. Electrolytes are reported in milligrams (mg) and values reported are per the manufacturer serving size. Replacement of sodium and potassium lost through sweat are more important than calcium and magnesium, which are lost at a lower rate and easier to replace through diet. Certain products such as Tailwind, regular Gatorade, Skratch also incorporate a tangible amount of carbohydrate to support training performance (but you may require additional carbohydrate supplementation).
Many of these products cost a premium for extremely low cost individual components. The lowest cost and most customizable way to supplement electrolytes it to make your own.
| Product | Serving | Sodium (Na+) | Potassium (K+) | Magnesium (Mg+) | Calcium (Ca+) | Carbohydrate Added / Simple Sugar Type | |
|---|---|---|---|---|---|---|---|
| Human Reference Range (in 1L of sweat) | 500-2000 | 100-500 | 0-100 | 0-100 | |||
| BodyArmor Flash IV | 1 pack / 7 g | 500 | 700 | 65 | 80 | 1g | |
| Dripdrop ORS | 1 stick / 10 g | 330 | 185 | 39 | 0 | 9g (sucrose and fructose) | |
| Gatorlyte | 1 pack / 15 g | 420 | 300 | 95 | 100 | 12g (sucrose)) | |
| Liquid IV | 1 stick / 16g | 560 | 370 | 0 | 0 | 13g (sucrose and glucose) | |
| LMNT | 1 pack / 6 g | 1000 | 200 | 60 | 0 | 2g | |
| Nunn Sport | 1 tab / 5 g | 300 | 150 | 25 | 13 | 4g (glucose) | |
| Pedialyte | 1 pack / 9 g | 260 | 180 | 0 | 0 | 7g (glucose) | |
| Saltstick Fast Chews | 2 tabs / 3.2 g | 100 | 30 | 6 | 10 | 2g (glucose) | |
| Tailwind Endurance | 1 scoop / 27g | 310 | 90 | 12 | 27 | 25g (glucose and sucrose) | |
| Gatorade | 1 pack / 35 g | 230 | 70 | 0 | 0 | 34g (sucrose and glucose) | |
| Skratch Hydration | 1 scoop / 22 g | 400 | 50 | 50 | 50 | 19g (sucrose and glucose) | |
| Mustard Packet* | 1 pack / 7g | 80 | 0 | 0 | 0 | 0 g | |
| Pickle Juice* | 1 shot / 30 mL | 260 | 0 | 0 | 0 | 0 g | |
| Pedialyte Advanced | 1 pack / 17 g | 650 | 370 | 0 | 0 | 12g (glucose + fructooligosaccharides)) |
If you would like other products added to this table, email me and I will add.
Do Electrolytes Prevent Exercise-associated Muscle Cramps?
The cause of exercise-associated muscle cramps is not well understood and not attributable to a single factor. [1] Many studies in endurance athletes show no association between cramping and level of hydration and blood electrolyte concentrations. System-wide full body cramping or bilateral cramping does appear to have a stronger association with hydration status and blood electrolytes.
More than likely, hydration status and blood electrolytes are a contributing factor for cramping, but more recent evidence suggests that exercise-associated muscle cramps may be mediated by muscle fatigue that alters neuromuscular control. Note in the table above there is an * by pickle juice and mustard. The beneficial action of these sodium sources may not be the sodium itself as it relates to cramp prevention. Rather they are sources of acetic acid, a compound of interest related to prevention or shortening the duration of cramps [2-4]. The proposed mechanism of acetic acid is to decrease alpha motor neuron activity through oropharyngeal neural reflexes. In short, a strong sensory stimulus could cause alpha motor neurons to become less excited which could prevent or reduce the severity of a cramp.
Ready to start?
Get started with nutrition coaching
References
1. Miller KC, McDermott BP, Yeargin SW, Fiol A, Schwellnus MP. An Evidence-Based Review of the Pathophysiology, Treatment, and Prevention of Exercise-Associated Muscle Cramps. J Athl Train. 2022 Jan 1;57(1):5-15.
2. Hooper Marosek SE, Antharam V, Dowlatshahi K. Quantitative Analysis of the Acetic Acid Content in Substances Used by Athletes for the Possible Prevention and Alleviation of Exercise-Associated Muscle Cramps. J Strength Cond Res. 2020 Jun;34(6):1539-1546.
3. Hoffman MD, Stuempfle KJ. Muscle Cramping During a 161-km Ultramarathon: Comparison of Characteristics of Those With and Without Cramping. Sports Med Open. 2015;1(1):24.
4. Miller KC, Mack GW, Knight KL, Hopkins JT, Draper DO, Fields PJ, Hunter I. Reflex inhibition of electrically induced muscle cramps in hypohydrated humans. Med Sci Sports Exerc. 2010 May;42(5):953-61.
Instagram: @kmcgrath.phd Facebook: @1modusenergy
Disclosure: I’m a a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. This help support keeping my website ad-free.
