Tag: electrolytes

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Electrolytes

Electrolytes

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.

ProductServingSodium (Na+)Potassium (K+)Magnesium (Mg+)Calcium (Ca+)Carbohydrate Added / Simple Sugar Type
Human Reference Range (in 1L of sweat)
500-2000100-5000-1000-100
BodyArmor Flash IV1 pack / 7 g50070065801g
Dripdrop ORS1 stick / 10 g3301853909g (sucrose and fructose)
Gatorlyte1 pack / 15 g4203009510012g (sucrose))
Liquid IV1 stick / 16g5603700013g (sucrose and glucose)
LMNT1 pack / 6 g10002006002g
Nunn Sport1 tab / 5 g30015025134g (glucose)
Pedialyte1 pack / 9 g260180007g (glucose)
Saltstick Fast Chews2 tabs / 3.2 g100306102g (glucose)
Tailwind Endurance1 scoop / 27g31090122725g (glucose and sucrose)
Gatorade1 pack / 35 g230700034g (sucrose and glucose)
Skratch Hydration1 scoop / 22 g40050505019g (sucrose and glucose)
Mustard Packet*1 pack / 7g800000 g
Pickle Juice*1 shot / 30 mL2600000 g
Pedialyte Advanced1 pack / 17 g6503700012g (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.  

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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.

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Beverage Hydration Index

The beverage hydration index provides the relative hydrating ability of different fluids relative to water. How do different drinks compare and what makes some beverages more hydrating than others?

Fuel your goals – contact me to explore nutrition coaching.

It’s useful to understand how different beverages can help maintain daily water balance in the body. Understanding how some beverages promote longer-term fluid retention, especially considering prolonged exercise and/or warmer climates is of practical benefit.

Common perception is that regular water and sports drinks containing electrolytes are more beneficial for hydration, and drinks such as coffee, tea, soda, and alcohol are dehydrating. Is this true?

In 2016, a team of researchers in the UK performed a fascinating study [1] comparing how well 13 different drinks were retained in the 2-4 hours immediately after consumption. Seventy-two volunteers consumed 1L of different fluids and then had their urine output monitored to indicate how much had been retained.

Correcting for differing water content, each beverage was given a Beverage Hydration Index (BHI) score. Still water was used as the reference point, with a rating of ‘1’. The higher the BHI, the more fluid was retained.

Comparing the 13 different beverages to water:

  • Oral rehydration solution aka ORS (e.g., Diarolyte, Pedialyte), orange juice, and milk are statistically more hydrating than water
  • Teas, sodas, and sports beverage (e.g., Powerade) statistically provide similar hydration to water
  • Black coffee and lager appear only very mildly dehydrating relative to water

The BHI highlights that there are several factors influencing the hydrating and dehydrating properties of different fluids, through changes in the rate at which the fluid is emptied from the stomach and absorbed in the small intestine versus how much is extracted in urine.

  • Volume of liquid consumed and rate of consumption influence rate of stomach emptying and absorption. To improve fluid retention it’s preferable to frequently sip fluids than to chug large volumes. Fast consumption of large volumes will more often than not result in the water passing through without as much storage in the body water pool. Why pee more without all the hydration benefit?
  • Other nutrients can strongly modulate hydration properties. Electrolytes, carbohydrate, protein, and fats in beverages delay stomach emptying and fluid absorption to varying degrees – the presence of these nutrients in fluids support hydration.
  • Presence of diuretics such as caffeine and alcohol can increase rate of excretion, and therefore can have a dehydrating effect. However, this appears to be highly dependent on other nutrients in the drink as well as the concentration of caffeine and alcohol. Low amounts of caffeine and alcohol are not especially dehydrating compared to water.

24-h hydration status does not appear to be very different in people drinking just water versus water plus a variety of other drinks, including water, cola, and fruit juice, provided that an adequate total volume is consumed. [2] Therefore, regarding specific drink selection within context of your overall nutrition and goals, consider the following:

  • Am I drinking enough overall fluid day to day to maintain hydration?
  • Am I sweating due to intense and/or prolonged training, training in warmer or more arid environments with infrequent opportunity to drink?
  • Do I need increased energy availability for prolonged training, or quickly restore muscle glycogen (for a second training bout)?
  • Protein: Will the milk help me better meet daily protein requirements?
  • Do I need additional calories or are zero-calorie options a better choice?
  • Is my stomach empty? BHI is an isolated measurement that was evaluated in the fasted state. Food will slow down fluid absorption and excretion rate.

Notes about caffeine and alcohol

A single high dose of caffeine, for example that contained in an energy drink (100 -200 mg) is unlikely to have a massive dehydration effect; as dosages approach and exceed 300 mg the additional volume of urine excreted may become significant. [3]

Alcohol content of the lager used in the study did not increase urine excretion over other drinks, but the effect of the alcohol may have been modulated by other nutrients in the beer. Counter to this idea, a different study specifically reported 12% greater urine excretion after ingestion of 1 L lager beer containing 4% alcohol compared with the ingestion of the same volume of a nonalcoholic control beer. [4]

While a few of the studied drinks were more hydrating than water, there are many drinks that are very similar to water which will support daily hydration needs. A few recommendations:

  • Start the day with a glass of water
  • EATING water will also support hydration. Consider that nearly all whole vegetables and fruits are >95% water by weight.
  • Replenish fluids during and after training. ORS is an excellent choice for prolonged intense exercise to replace sweat. Additional carbohydrates may be necessary to maintain energy availability for extended training. It’s lowest cost to make your own, or purchase products such as Pedialyte, Nuun, DripDrop.
  • Milk is an all-star as a post-workout beverage to support rehydration, total protein intake, and glycogen re-synthesis. Ron Burgundy is wrong!
Beverage Hydration Index

[1] Maughan, RJ, Watson, P., et al, A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index, Am J Clin Nutr 103: 717-723, 2016.

[2] Tucker M.A., Ganio M.S., et al. Hydration status over a 24-h period is not affected by ingested beverage composition. J Am Coll Nutr 34:318–27, 2015.

[3] Maughan R.J., Griffin J., Caffeine ingestion and fluid balance: a review. J Hum Nutr Diet 16:411–20, 2003.

[4] Hobson R.M., Maughan R.J. Hydration status and the diuretic action of a small dose of alcohol. Alcohol, 45:366–73, 2010.

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Make Your Own Endurance Fuel

Contact me if you’re looking for a personalized nutrition strategy. Get the most out of training and recovery for your event.

Make your own endurance fuel at ~3x lower cost, with a wide possibility of flavors and customizations. That’s cash towards your next race or investment into training, nutrition, and gear!

Endurance fueling – practice makes perfect

Single and multi-stage endurance events result in sizeable losses to energy stores, water, and electrolytes. Your endurance fuel should offset these losses and mitigate fatigue from dehydration and lower availability of fuel to contracting muscles. Experimentation and practice of fluid and food intake in training is important to quantify your appropriate level of carbohydrate and salt intake for events.

The risk of developing gastrointestinal (GI) distress increases twofold for those not accustomed to fluid and food ingestion during exercise,[1] and >30% of athletes exhibit one or more GI symptoms during exhaustive endurance events. [2] It’s likely attributable to a combination of maldigestion and malabsorption of nutrients, changes in transit time of nutrients through the gut, and improper fluid and nutrient intake. Experimentation and continued practice can be the difference between an all-time best and a DNF/DOR. Use training time wisely to understand what works/doesn’t work for you. Consider that your gut may not behave the same at hour one versus hour eight or more.

A good liquid endurance fuel will:

  • Replace water. As little as 2% decrease in body water can impair performance [3], and insufficient fluid replacement may increase the frequency of GI symptoms.[4] Replacement rate can vary considerably based on climate, exertion, body composition, and other factors, but a good base is in the 0.45-0.75 L/h range for extended submaximal efforts.[5]
  • Replace salt. Electrolyte replacement depends primarily on sweat rate, dietary practices, acute consumption, and genetics.
  • Attenuate energy deficit (provide calories).
  • Be near isotonic. Fluid should have similar concentration of solutes as blood plasma (275-295 mOsm/kg). Drinking a fluid with similar osmotic pressure as body fluids supports body water-electrolyte balance.
  • Encourage drinking. Should be tasty enough to make you want to sip. Sipping frequently is better than periodic gulping to maximize fluid and nutrient uptake.

Endurance fuel components and taste

Summary of ingredients of popular endurance fuels and the taste they impart:

Making your own endurance fuel

Endurance Fuel

Weighing the powders: to precisely weigh out powders, you’ll need a digital scale that can measure to the tenths of grams to make individual servings. I find it’s more practical to prepare in larger batches (in which case you can use a food scale to the hundredths). After mixing, place in a large mason jar, shake well and store for later use.

  • Electrolytes: Sweating rate and electrolyte concentration in sweat is variable based on physiology, intensity of exercise, and environment. The below table summarizes the main components of sweat on a per liter basis. For the recipe, I selected moderate levels. This endurance fuel, similar to popular products on the market includes major and minor electrolytes, with sodium and chloride the most important. If you’re getting sufficient potassium, calcium, and magnesium from your diet, adding them to your electrolyte is unlikely to provide benefit.
  • Carbohydrate (CHO): Glucose, or combinations of glucose + fructose, and sucrose rapidly replace muscle glycogen and maintain blood glucose required for muscle contraction, and support water absorption.[1,7] A good base for long submaximal efforts is 30-50g/hr,[5] supplementing with carbohydrates from food or gels as appropriate. For high intensity efforts, pushing upwards of 100g/hr is possible (with gut training and use of multiple transportable carbohydrates). [6] The recipe uses 70g/L of glucose (resulting in an intake rate of 35g-50g CHO/hr with my estimate total fluid intake rate).
  • Caffeine: Caffeine is an established ergogenic aid for sustained endurance exercise, primarily by reducing perception of pain [8,9], enhancing cognitive performance, [10] and increasing time to fatigue in skeletal muscle contraction.[11] Addition of caffeine is entirely optional; a moderate “topping off” dosage for multi-hour events is in the 70-125mg/hr range, with a pre-dosage of 3-6mg/kg BW 30-90 min before event start. Many prefer to supplement with caffeine separately using gels or other means.
  • Flavorings: This recipe is fairly tart using 2g of citric acid per liter; adjust this amount up or down to your preference. To change the flavor, Nature’s Flavors powders come in a brilliant variety. For the recipe, I used 2g apple powder which in combination with the citric acid provides a sour apple flavor, much like a Jolly Rancher candy.

Composition and cost comparison

After extensive personal testing on multi-hour training runs in both hot/arid and hot/humid climates and a elevation trail 50K on a hot day, here’s the final comparison. I was still happy drinking it until I finished just under 7 hours later.

If you’re training extensively, you’ll easily save several hundred dollars per year on fuel by making your own. Have fun and reach out anytime if you have questions!

Make your own endurance fuel at ~3x lower cost, with a wide possibility of flavors and customizations. That’s cash towards your next race or investment into training, nutrition, and gear!

[1] de Oliveira, E.P.; Burini, R.C.; Jeukendrup, A., Gastrointestinal complaints during exercise: prevalence, etiology, and nutritional recommendations, Sports Med. 44, S79-85, (2014).

[2] Romijn, J. A.; Coyle, E. F.; et al., Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity. American Journal of Physiology: Endocrinology and Metabolism, 265, E380–E391, (1993).

[3] Jeukendrup, A.; Gleeson, M., Henry. Sports Nutrition, Human Kinetics; 2nd edition (2009).

[4] Smith, J.W.; Bello, M.L.; Ffion, G., A Case-Series Observation of Sweat Rate Variability in Endurance-Trained Athletes, Nutrients, 13, 1807, (2021).

[5] Tiller, N.B.; Roberts, J.D.; et al., International Society of Sports Nutrition Position Stand: nutritional considerations for single-stage ultra-marathon training and racing, J Int Soc Sports Nutr., 16(1), 50, (2019).

[6] Trommelen, J.; Fuchs, C.J.; et al., Fructose and Sucrose Intake Increase Exogenous  Carbohydrate Oxidation during Exercise, Nutrients, 9(2), 167, (2017).

[7] Giso, C.V.; Summers, R.W.; Schedl, H.P.; Bleiler, T.L., Intestinal water absorption from select carbohydrate solutions in humans. J. Appl. Physiol. 73, 2142, (1992).

[8] Laurent. D.; Schneider, K.E.; Prusaczyk, W.K.; et al., Effects of caffeine on muscle glycogen utilization and the neuroendocrine axis during exercise. J Clin Endocrinol Metab, 85, 2170, (2000).

[9] Grossman, A; Sutton, J.R., Endorphins: What are they? How are they measured? What is their role in exercise?, Med Sci Sports Exerc, 17 ,74, (1985).

[10] Ivy, J.L.; Costill, D.L.; et al., Influence of caffeine and carbohydrate feedings on endurance performance. Med Sci Sports Exerc, 11, 6, (1979).

[11] Kalmar, J.M.; Cafarelli, E. Effects of caffeine on neuromuscular function. J Appl Physiol, 87, 801, (1999).

[12] Vitale, K; Getzin, A., Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations. Nutrients, 11(6), 1289, (2019).

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.